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  Subjects -> ELECTRONICS (Total: 154 journals)
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 1)
Advances in Electronics     Open Access   (Followers: 3)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 5)
Advances in Microelectronic Engineering     Open Access   (Followers: 2)
Advances in Power Electronics     Open Access   (Followers: 7)
Aerospace and Electronic Systems, IEEE Transactions on     Hybrid Journal   (Followers: 104)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 12)
Annals of Telecommunications     Hybrid Journal   (Followers: 5)
APL : Organic Electronics and Photonics     Hybrid Journal   (Followers: 2)
APSIPA Transactions on Signal and Information Processing     Open Access   (Followers: 6)
Archives of Electrical Engineering     Open Access   (Followers: 9)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 5)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 10)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 16)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 15)
Biomedical Instrumentation & Technology     Hybrid Journal   (Followers: 5)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 5)
BULLETIN of National Technical University of Ukraine. Series RADIOTECHNIQUE. RADIOAPPARATUS BUILDING     Open Access   (Followers: 2)
Bulletin of the Polish Academy of Sciences : Technical Sciences     Open Access  
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 13)
China Communications     Full-text available via subscription   (Followers: 4)
Circuits and Systems     Open Access   (Followers: 10)
Consumer Electronics Times     Open Access   (Followers: 4)
Control Systems     Hybrid Journal   (Followers: 26)
Electronic Design     Partially Free  
Electronic Markets     Hybrid Journal   (Followers: 5)
Electronic Materials Letters     Hybrid Journal   (Followers: 3)
Electronics     Open Access   (Followers: 9)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 5)
Electronics Letters     Hybrid Journal   (Followers: 20)
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 23)
Energy Harvesting and Systems : Materials, Mechanisms, Circuits and Storage     Hybrid Journal   (Followers: 1)
EPJ Quantum Technology     Open Access  
EURASIP Journal on Embedded Systems     Open Access   (Followers: 9)
Facta Universitatis, Series : Electronics and Energetics     Open Access  
Frequenz     Hybrid Journal   (Followers: 3)
Frontiers of Optoelectronics     Hybrid Journal   (Followers: 2)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 20)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 3)
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 15)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 13)
IEEE Consumer Electronics Magazine     Full-text available via subscription   (Followers: 18)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 12)
IEEE Journal of the Electron Devices Society     Open Access   (Followers: 3)
IEEE Power Electronics Magazine     Full-text available via subscription   (Followers: 7)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 10)
IEEE Transactions on Audio, Speech, and Language Processing     Hybrid Journal   (Followers: 13)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 26)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 17)
IEEE Transactions on Electron Devices     Hybrid Journal   (Followers: 8)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 14)
IEEE Transactions on Power Electronics     Hybrid Journal   (Followers: 21)
IEICE - Transactions on Electronics     Full-text available via subscription   (Followers: 8)
IEICE - Transactions on Information and Systems     Full-text available via subscription   (Followers: 7)
IET Microwaves, Antennas & Propagation     Hybrid Journal   (Followers: 6)
IET Power Electronics     Hybrid Journal   (Followers: 14)
IET Wireless Sensor Systems     Hybrid Journal   (Followers: 10)
IETE Journal of Education     Open Access   (Followers: 2)
IETE Journal of Research     Open Access   (Followers: 9)
IETE Technical Review     Open Access   (Followers: 4)
Industrial Electronics, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 3)
Informatik-Spektrum     Hybrid Journal  
Instabilities in Silicon Devices     Full-text available via subscription  
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 2)
International Journal of Advanced Electronics and Communication Systems     Open Access   (Followers: 5)
International Journal of Advanced Research in Computer Science and Electronics Engineering     Open Access   (Followers: 20)
International Journal of Advances in Telecommunications, Electrotechnics, Signals and Systems     Open Access   (Followers: 3)
International Journal of Aerospace Innovations     Full-text available via subscription   (Followers: 12)
International Journal of Antennas and Propagation     Open Access   (Followers: 7)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 1)
International Journal of Biomedical Nanoscience and Nanotechnology     Hybrid Journal   (Followers: 6)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 4)
International Journal of Computer & Electronics Research     Full-text available via subscription   (Followers: 2)
International Journal of Control     Hybrid Journal   (Followers: 13)
International Journal of Electronics     Hybrid Journal   (Followers: 2)
International Journal of Electronics & Data Communication     Open Access   (Followers: 4)
International Journal of Electronics and Telecommunications     Open Access   (Followers: 3)
International Journal of Granular Computing, Rough Sets and Intelligent Systems     Hybrid Journal   (Followers: 1)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 1)
International Journal of Nano Devices, Sensors and Systems     Open Access   (Followers: 4)
International Journal of Nanoscience     Hybrid Journal  
International Journal of Numerical Modelling:Electronic Networks, Devices and Fields     Hybrid Journal   (Followers: 2)
International Journal of Power Electronics     Hybrid Journal   (Followers: 8)
International Journal of Review in Electronics & Communication Engineering     Open Access   (Followers: 2)
International Journal of Sensors, Wireless Communications and Control     Hybrid Journal   (Followers: 3)
International Journal of Superconductivity     Open Access  
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 2)
International Journal on Communication     Full-text available via subscription   (Followers: 11)
International Journal on Electrical and Power Engineering     Full-text available via subscription   (Followers: 10)
International Transaction of Electrical and Computer Engineers System     Open Access  
Journal of Biosensors & Bioelectronics     Open Access   (Followers: 2)
Journal of Advanced Dielectrics     Open Access   (Followers: 1)
Journal of Artificial Intelligence     Open Access   (Followers: 5)
Journal of Circuits, Systems, and Computers     Hybrid Journal   (Followers: 1)
Journal of Computational Intelligence and Electronic Systems     Full-text available via subscription  
Journal of Electrical and Electronics Engineering Research     Open Access   (Followers: 4)
Journal of Electrical Bioimpedance     Full-text available via subscription   (Followers: 2)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 2)

        1 2 | Last

Journal Cover   IEEE Transactions on Power Electronics
  [SJR: 2.866]   [H-I: 128]   [21 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0885-8993
   Published by Institute of Electrical and Electronics Engineers (IEEE) Homepage  [176 journals]
  • IEEE Power Electronics Society Information
    • PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Table of Contents
    • PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • IEEE Transactions on Power Electronics publication information
    • PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • EditorialReflections on 2015 and Entering the Active Content Age
    • Authors: Lehman; B.;Chung, H.S.H.;
      Pages: 3 - 4
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Modulation Methods for Three-Level Neutral-Point-Clamped Inverter
           Achieving Stress Redistribution Under Moderate Modulation Index
    • Authors: Ma; K.;Blaabjerg, F.;
      Pages: 5 - 10
      Abstract: This letter investigates the loss and thermal behaviors of a three-level neutral-point-clamped (3L-NPC) inverter undergoing moderate modulation index, which is typically presented during minor voltage sags of the power grid or speed changes of the electric machines. A series of new space vector modulation methods is then proposed to relocate the thermal loading among the power devices. It is concluded that with some of the proposed modulation methods, the device loading in the 3L-NPC inverter can be effectively modified and optimized, and the junction temperature of the most stressed devices can be also relieved. The control ability of dc bus midpoint potential, which is one of the crucial considerations for the 3L-NPC topology, is also investigated when applying the proposed modulation methods.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Modeling and Efficiency Analysis of Multiphase Resonant-Switched
           Capacitive Converters
    • Authors: Pillonnet; G.;
      Pages: 11 - 14
      Abstract: This paper presents an analytical method to evaluate pertinent data of the resonant capacitive switching converter, especially the voltage gain and power efficiency. Instead of long transient simulation time, the proposed model uses frequency decomposition to speed-up computation. This method is valid for N-phase operation, and extends the recently published studies on this promising topology outside zero-current/voltage switching conditions. Thanks to this tractable expression, we also reveal the intrinsic efficiencies over the voltage gain of two- and three-phase structures working at the resonant frequency in step-down operation. These results help to gain better understanding of multiphase operation, and encourage additional studies to use the full capability offered by the resonant-switched capacitor converter especially for power on-chip integration.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Optimal Inductor Current in Boost DC/DC Converters Operating in Burst Mode
           Under Light-Load Conditions
    • Authors: Reverter; F.;Gasulla, M.;
      Pages: 15 - 20
      Abstract: This letter analyzes how the efficiency of boost dc/dc converters operating in burst mode under light-load conditions can be improved by an appropriate selection of the inductor current that transfers energy from the input to the output. A theoretical analysis evaluates the main power losses (fixed, conduction, and switching losses) involved in such converters, and how do they depend on the inductor current. This analysis shows that there is an optimal value of this current that causes minimum losses and, hence, maximum efficiency. These theoretical predictions are then compared with experimental data resulting from a commercial boost dc/dc converter (TPS61252), whose average inductor current is adjustable. Experimental results show that the use of the optimal inductor current, which was around 340 mA for an output voltage of 5 V, provides an efficiency increase of 7%.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Simple Method for Sinusoidal Input Currents of Matrix Converter Under
           Unbalanced Input Voltages
    • Authors: Lei; J.;Zhou, B.;Bian, J.;Qin, X.;Wei, J.;
      Pages: 21 - 25
      Abstract: When matrix converter works under unbalanced input voltages, sinusoidal input currents could be obtained if the input power factor angle in conventional control strategy is modified based on the positive and negative sequence components of input voltages. Some existing literature realized this goal by using sequence component separation, which was usually complicated and/or storage-consuming. Instead, a simple realization method is proposed by this letter to obtain sinusoidal input currents, which constructs the expected input power factor angle by filtering the square of input voltage vector with a notch filter. The proposed method is easy to implement, since no sequence extraction algorithm is required. Experimental results demonstrate that compared with the existing realization methods, the proposed method reduces the computation time and storage space with identical performance of improving input currents quality.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Impedance-Based Analysis of Grid-Synchronization Stability for Three-Phase
           Paralleled Converters
    • Authors: Wen; B.;Dong, D.;Boroyevich, D.;Burgos, R.;Mattavelli, P.;Shen, Z.;
      Pages: 26 - 38
      Abstract: Grid synchronization stability issues and subsynchronous oscillations between synchronous generators exist in electrical power systems. Three-phase voltage-source converters (VSCs) are being installed more and more in the grid to improve efficiency or to utilize renewable energy sources. The same stability issues between VSCs are also reported and analyzed using a small-signal model of phase-locked loops (PLLs). This paper proposes a different impedance-based analysis method. The proposed method shows that synchronization instability in a VSC system is due to the negative incremental resistance behavior of grid-tied inverters' impedance when they are modeled in the d–q frame. System can be stabilized simply by changing the inverter's PLL design. Experimental results verify the analysis and the proposed method.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • An SD Card Flash-Memory-Based Implementation of a Multioptimal Three-Phase
           PWM Generator
    • Authors: Neacsu; D.O.;Zheng, Y.;Lehman, B.;
      Pages: 39 - 51
      Abstract: This paper demonstrates for the first time the use of a very large secure digital card flash memory to the design of a three-phase pulse width modulation (PWM) generator and describes the hardware and software used for implementation. The new digital architecture differs from the conventional counter-based implementation, and it follows a preprogrammed optimal PWM pattern that is read from memory with magnitude and phase as coordinates. This architecture allows the inclusion of multiple optimization criteria within the PWM pattern. This digital architecture becomes valuable since the switching instants can be set in any conceivable manner, away from the rigid constraint of a repetitive sequence of states on each PWM period. Experimental results validate that the proposed new architecture allows simple and low cost implementation of complicated PWM patterns with harmonic reductions that could not otherwise be achieved for low cost.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • 3-D-Printed Air-Core Inductors for High-Frequency Power Converters
    • Authors: Liang; W.;Raymond, L.;Rivas, J.;
      Pages: 52 - 64
      Abstract: This paper presents the design, modeling, and characterization of 3-D-printed air-core inductors for high-frequency power electronics circuits. The use of 3-D modeling techniques to make passive components extends the design flexibility and addresses some of the fabrication limitations of traditional processes. Recent work [1]– [9] has demonstrated the feasibility of incorporating air-core inductors in high-frequency ( > 10 MHz) switching power converters. These implementations have used discrete wire wound solenoids and toroids, and planar components that use printed circuit board traces or microfabrication techniques to make air-core inductors. However, realizations of such components have limitations in performance and applicability including open paths conducive to the flow of leakage fields, and difficulties in achieving optimal cross section to minimize loss. Along with the current effort of involving 3-D printing technology to make inductors [10], [11], we propose the use of 3-D printing and casting/plating techniques as a simple and accessible alternative that adds flexibility and functionality to the air-core inductor design for high-frequency power conversion at moderate to high-power (e.g., tens to thousands of watts) and high-voltage (greater than 100 V) levels. In this paper, we present several examples of air-core inductors realized using 3-D printing and casting/plating techniques to give an idea of the geometries that are possible to design. Moreover, we show that some of these designs can lead to improved electrical performance. This paper also describes the tools used by the authors to design, fabricate, and characterize the electromagnetic performance of the air-core inductors. The s- ftware used to generate the 3-D scaffolds for the inductors are freely available and easily accessible. Readers are encouraged to explore more possibilities of geometries that can lead to better performance with the ease of manufacturing. As progress in additive manufacturing continues, we envision 3-D printing of a complete scaffold structure that after plating (or casting) will contain all resonant passive components of an RF switching converter. Toward this goal, we present a 70-W prototype 27.12-MHz resonant inverter that incorporates some of the 3-D-printed components developed for this paper.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Precise Dimming and Color Control of LED Systems Based on Color Mixing
    • Authors: Lee; A.T.L.;Chen, H.;Tan, S.;Hui, S.Y.R.;
      Pages: 65 - 80
      Abstract: This paper proposes a closed-loop nonlinear scheme for precisely controlling the luminosity and correlated color temperature (CCT) of a bicolor adjustable light-emitting diode (LED) lamp. The main objective is to achieve a precise and fully independent dimming and CCT control of the light mixture emitted from a two-string LED lamp comprising warm-white and cool-white color LEDs, regardless of the operating conditions and throughout the long operating lifetime of the LED lamp. The proposed control method is formulated using the nonlinear empirical LED model of the bicolor white LED system. Experimental results show that with the proposed closed-loop nonlinear approach, both CCT and dimming control of the bicolor lamp is significantly more accurate and robust to ambient temperature variations, ambient light interference, and LED aging than the conventional linear approach used in existing products. The maximum error in luminous flux employing the proposed closed-loop nonlinear approach is 3%, compared with 20% using the closed-loop linear approach. The maximum deviation in CCT is only 1.78%, compared with 27.5% with its linear counterpart.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Novel PWM High Voltage Conversion Ratio Bidirectional Three-Phase DC/DC
           Converter With Y–Δ Connected Transformer
    • Authors: Jin; K.;Liu, C.;
      Pages: 81 - 88
      Abstract: In order to solve the problem of high voltage conversion ratio between dc bus and energy storage unit, a novel bidirectional three-phase dc/dc converter applicable to high-power condition is proposed in this paper. With the new PWM strategy and inherent ability of increasing voltage conversion ratio of Y–Δ connected transformer, the voltage conversion ratio is doubled. With the new PWM strategy, the effective duty cycle range of three-phase dc/dc converter is expanded, which results in halved filter inductance. Three-phase full-bridge structure is connected to the dc bus, while current-tripler unit is connected to the battery. As three-phase interleaved structure is adopted, not only current stress of switches decreases but also the frequency of input and output current ripple increases to three times of switching frequency, which leads to smaller filters and extended lives cycle of batteries. The operating principle and characteristics of the converter are analyzed in detail. A prototype with the 360-V dc bus converted to 48 V/42 A batteries was built and the results are given based on the experiments.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Comprehensive DC Power Balance Management in High-Power Three-Level
           DC–DC Converter for Electric Vehicle Fast Charging
    • Authors: Tan; L.;Wu, B.;Rivera, S.;Yaramasu, V.;
      Pages: 89 - 100
      Abstract: With the increasing popularity of electric vehicles, there is an urgent demand to shorten the charging time, so the development of high-power charging stations with fast chargers is necessary to alleviate range anxiety for drivers. The charging station based on the neutral-point-clamped (NPC) converter can bring many merits, but it has unbalanced power problems in the bipolar dc bus. To solve this issue, comprehensive dc power balance management (PBM) in conjunction with high-power three-level dc–dc converter based fast charger is proposed in this paper. The active dc power balance management (APBM) is proposed to assist the central NPC converter in balancing power so that the additional balancing circuit is eliminated; while the passive dc power balance management (PPBM) is proposed to eliminate the fluctuating neutral-point currents and to ensure the balanced operation of fast chargers. The principles of APBM and PPBM are researched, the efficient integration between them is studied, and the overall control scheme for the fast charger is proposed. The power balance limits of APBM are explored, while the circulating currents of PPBM are analyzed. Simulation and experimental results are presented to verify the effectiveness of the proposed fast charger with PBM functions.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A 98.7% Efficient Composite Converter Architecture With
           Application-Tailored Efficiency Characteristic
    • Authors: Chen; H.;Sabi, K.;Kim, H.;Harada, T.;Erickson, R.;Maksimovic, D.;
      Pages: 101 - 110
      Abstract: A dc–dc boost composite converter architecture is introduced that can lead to optimized efficiency over a range of operating points dictated by the application requirements. The composite converter system employs dissimilar modules to minimize the ac power losses in the indirect power conversion paths. It is composed of three converter modules: buck converter, boost converter, and a dual active bridge converter that operates as a dc transformer (DCX). Each module processes partial power, with reduced voltage rating. With the same semiconductor area and same magnetics volume, substantial efficiency improvements and reductions in capacitor size are achieved relative to a conventional boost architecture. It is possible to design each module to optimize efficiency over a wide operating range, including pass-through modes that exhibit very low loss. A 10-kW boost composite converter is experimentally demonstrated having 98.7% efficiency at a critical partial power point, with similar very high efficiencies achieved over a wide operating range.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Series-Input Parallel-Output Modular-Phase DC–DC Converter With
           Soft-Switching and High-Frequency Isolation
    • Authors: Mohammadpour; A.;Parsa, L.;Todorovic, M.H.;Lai, R.;Datta, R.;Garces, L.;
      Pages: 111 - 119
      Abstract: Multiphase soft-switching high-frequency isolated dc–dc converter is proposed for power conversion in modular stacked HVDC power transmission and distribution system. Input-series output-parallel connection of current-fed full-bridge dc–dc converter modules is proposed to increase voltage blocking capability at the input and decrease current ripple at the output. Basic power electronic building block is zero-current switching (ZCS) full-bridge phase-shift pulsewidth-modulated (PWM) dc–dc converter. Phase shift between switches in each leg of the converter is adjusted to control power flow, while phase shift between gate signals of individual phases is selected according to the number of phases in order to minimize ripple of the output voltage. Converter analysis is carried out to develop a simple equivalent boost converter model of the three-phase soft-switching converter suitable for system-level analysis and simulation. Strategies are developed to ensure fast detection of faults and continued operation of the converter in the case of fault in one phase module. To verify the proposed system design and analysis, experimental results on scaled-down laboratory prototype are presented for a three-phase ZCS dc–dc converter.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Coupled Inductors in Interleaved Multiphase Three-Level DC–DC
           Converter for High-Power Applications
    • Authors: Lu; S.;Mu, M.;Jiao, Y.;Lee, F.C.;Zhao, Z.;
      Pages: 120 - 134
      Abstract: This paper investigates and evaluates coupled inductors (CIs) in the interleaved multiphase three-level dc–dc converter. If non-CIs are used in the multiphase three-level dc–dc converter, interleaving operation of the converter will increase inductor current ripple, although the overall output current ripple and common-mode (CM) voltage will become smaller. To reduce inductor current ripple, inverse-CIs are employed. The current ripple in the CI is analyzed in detail. The benefits of the three-level dc–dc converter with CIs under interleaving operation are evaluated. By adding CIs and working under interleaving operation, smaller inductor current ripple, smaller overall output current ripple, and smaller CM voltage can be achieved simultaneously compared with the noninterleaving case. The analysis results are verified by simulations and 10 kW scale-down experiments.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Multilevel Inverter Topologies With Reduced Device Count: A Review
    • Authors: Gupta; K.K.;Ranjan, A.;Bhatnagar, P.;Sahu, L.K.;Jain, S.;
      Pages: 135 - 151
      Abstract: Multilevel inverters have created a new wave of interest in industry and research. While the classical topologies have proved to be a viable alternative in a wide range of high-power medium-voltage applications, there has been an active interest in the evolution of newer topologies. Reduction in overall part count as compared to the classical topologies has been an important objective in the recently introduced topologies. In this paper, some of the recently proposed multilevel inverter topologies with reduced power switch count are reviewed and analyzed. The paper will serve as an introduction and an update to these topologies, both in terms of the qualitative and quantitative parameters. Also, it takes into account the challenges which arise when an attempt is made to reduce the device count. Based on a detailed comparison of these topologies as presented in this paper, appropriate multilevel solution can be arrived at for a given application.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Novel Power Converter Topology for Electrostatic Precipitators
    • Authors: Vukosavic; S.N.;Peric, L.S.;Susic, S.D.;
      Pages: 152 - 164
      Abstract: In this paper, we introduced an improved transformer-based parallel-resonant converter, suitable for high voltage, high power dc loads. The resonant capacitors are connected in parallel with diodes of the high voltage rectifier, thus restraining dv/dt stress in high voltage circuits. The LC tank resonant frequency is well beyond the switching frequency, reducing in this way the VA rating of LC components. With rated load, the output current of the IGBT bridge is equal to zero at switching instants, and the switching losses are very low. Proposed subresonant circuit requires lower primary current for the given output power and it has reduced IGBT losses. Experimental setup delivers 79 kW with an efficiency of 96.78%. The paper explains the switching states of the devised topology, and provides the guidelines for designing the power transformer, the LC tank and controls. Analytical prediction of the performance curves is verified both in laboratory and by the field tests with an electrostatic precipitator plant.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Model Assisted Testing Scheme for Modular Multilevel Converter
    • Authors: Tang; Y.;Ran, L.;Alatise, O.;Mawby, P.;
      Pages: 165 - 176
      Abstract: Systems based on the modular multilevel converter (MMC) concept can be used for a variety of applications including high voltage direct current transmission and flexible alternating current transmission system devices for power system control. In these applications, both the manufacturer and operator are keen to understand the stress conditions that the submodules are subject to. It is important to test for reliability of the submodules as a function of the design and control variables. This paper proposes a model assisted submodule testing scheme for an MMC that can be used in any of the possible applications. The submodules can be thoroughly tested individually before the complete MMC is built. Experimental measurements have shown the validity and accuracy of the proposed method with close attention given to the synchronization between the signals. The current (with dc bias and harmonic components) passing through the submodule, the switching sequence, and the capacitor voltage are shown to be identical to what the submodule would be subjected to when installed in a complete MMC. This test method is capable of facilitating research and development exercises through examining the electromagnetic and electrothermal characteristics.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • New Measuring Technique for Reducing the Number of Voltage Sensors in
           Modular Multilevel Converters
    • Authors: Picas; R.;Zaragoza, J.;Pou, J.;Ceballos, S.;Balcells, J.;
      Pages: 177 - 187
      Abstract: This paper presents a new technique for measuring the capacitor voltages in a modular multilevel converter using a reduced number of voltage sensors. With this technique, the minimum number of voltage sensors per arm is two. Each sensor measures the output voltage of a set of submodules (SMs) connected in series and acquires a new measurement when there is only one SM activated within the set. The acquired value corresponds to the capacitor voltage of the activated SM minus the voltage drops produced in the switches. A simple mathematical model is used to estimate all the SM capacitor voltages, and it is then updated whenever there is a new measurement available. An algorithm that enforces the periodic update of the voltage measurements is also presented. The proposed measuring technique highly reduces the number of voltage sensors; hence reducing the complexity and costs of the signal conditioning and data acquisition stages. Simulation and experimental results are presented to demonstrate the efficiency of the proposed technique.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Dynamic Voltage Restorer Based on Three-Phase Inverters Cascaded Through
           an Open-End Winding Transformer
    • Authors: de Almeida Carlos; G.A.;dos Santos, E.C.;Jacobina, C.B.;Mello, J.P.R.A.;
      Pages: 188 - 199
      Abstract: This paper investigates a dynamic voltage restorer (DVR) composed of two conventional three-phase inverters series cascaded through an open-end winding (OEW) transformer, denominated here DVR-OEW. The DVR-OEW operating with either equal or different dc-link voltages is examined. The proposed topology aims to regulate the voltage at the load side in the case of voltage sags/swells, distortion, or unbalance at the grid voltage. A suitable control strategy is developed, including space-vector analysis, level-shifted PWM and its equivalent optimized single-carrier PWM, as well as the operating principles and characteristics of the DVR. Comparisons among the DVR-OEW and conventional configurations, including a neutral-point clamped converter-based DVR, are furnished. The main advantages of the DVR-OEW compared to the conventional topologies lie on: 1) reduced harmonic distortion, 2) reduced converter losses, and 3) reduced voltage rating of the power switches. Simulated and experimental results are presented to validate the theoretical studies.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Negative Sequence Current Optimizing Control Based on Railway Static Power
           Conditioner in V/v Traction Power Supply System
    • Authors: Zhang; D.;Zhang, Z.;Wang, W.;Yang, Y.;
      Pages: 200 - 212
      Abstract: In order to bring railway static power conditioner (RPC) into full play in suppressing negative sequence current in the V/v traction power supply system, the reason of negative sequence current and compensation mechanism were analyzed, and the mathematical model with minimum negative sequence current under the constraint of voltage fluctuation, power factor, device capacity, transformer winding capacity, and energy conservation was set up. For solving the small-scale multidimensional nonlinear and constrained optimization problem, an intelligent algorithm based on sequential quadratic programming (SQP) method is proposed through a comparative analysis of existing optimization algorithms and the traditional analytical method. The proposed algorithm is capable to complete an optimizing computation process in several milliseconds with the precision of 0.1 A, and its computational efficiency and precision can meet the needs for real-time control of RPC. A self-adaption real-time optimization computing platform was built in combination with detectable analogue quantities of traction power supply system and RPC, including catenary network voltages, feeder currents, and compensation currents. Simulation and engineering experimentation results are provided to illustrate that the model and its computation are effective and feasible.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Grid-Current-Feedback Active Damping for LCL Resonance in
           Grid-Connected Voltage-Source Converters
    • Authors: Wang; X.;Blaabjerg, F.;Loh, P.C.;
      Pages: 213 - 223
      Abstract: This paper investigates active damping of LCL-filter resonance in a grid-connected voltage-source converter with only grid-current feedback control. Basic analysis in the s-domain shows that the proposed damping technique with a negative high-pass filter along its damping path is equivalent to adding a virtual impedance across the grid-side inductance. This added impedance is more precisely represented by a series RL branch in parallel with a negative inductance. The negative inductance helps to mitigate phase lag caused by time delays found in a digitally controlled system. The mitigation of phase-lag, in turn, helps to shrink the region of nonminimum-phase behavior caused by negative virtual resistance inserted unintentionally by most digitally implemented active damping techniques. The presented high-pass-filtered active damping technique with a single grid-current feedback loop is thus a more effective technique, whose systematic design in the z -domain has been developed in this paper. For verification, experimental testing has been performed with results obtained matching the theoretical expectations closely.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Full-Bridge Reactive Power Compensator With Minimized-Equipped Capacitor
           and Its Application to Static Var Compensator
    • Authors: Isobe; T.;Shiojima, D.;Kato, K.;Hernandez, Y.R.R.;Shimada, R.;
      Pages: 224 - 234
      Abstract: This paper discusses reactive power compensators from the point of stored energy in the capacitor, and proposes a single-phase full-bridge configuration of semiconductor switches to be used with reduced equipped capacitance for reactive power compensation. By applying this concept to shunt-type static var compensator, a static synchronous compensator can be achieved with reduced-sized capacitor. Additionally, the switching loss can be reduced due to its distinctive capacitor voltage waveform, which swings at the double of the line frequency. Modulation technique and capacitor voltage control method based on the reduced capacitance and high-voltage ripple in the capacitor are proposed. The concept and control method were confirmed with small-scale experiments.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Improved Design of Sliding-Mode Controllers Based on the Requirements of
           MPPT Techniques
    • Authors: Montoya; D.G.;Ramos-Paja, C.A.;Giral, R.;
      Pages: 235 - 247
      Abstract: In many grid-connected applications, a dc/dc switching converter is usually connected between the PV modules and the inverter. This paper presents an improved procedure to design a sliding controller for the PV system, which drives the PV voltage to follow a reference provided by an external MPPT algorithm and mitigates the perturbations caused by the irradiance changes and oscillations in the bulk voltage. By considering that the switching surface is the linear combination of the input capacitor current and the PV voltage error, the proposed design exhibits advantages in comparison with existing solutions that rely in the linearization of inner current loop dynamics. The proposed integral procedure, by taking also into account the effects in the closed-loop system dynamics of a reference filter, ensures a stable sliding regime in all the desired operation range of the system, while the settling time and overshoot of the PV voltage required by an MPPT algorithm are provided. Differently from a previous similar but less rigorous approach, the switching function and reference filter parameters are obtained by numerically solving a set of nonlinear equations. Simulations and experiments were used to demonstrate the efficiency of the proposed solution in presence of environmental and load perturbations.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • High Weighted Efficiency in Single-Phase Solar Inverters by a
           Variable-Frequency Peak Current Controller
    • Authors: Levron; Y.;Erickson, R.W.;
      Pages: 248 - 257
      Abstract: This paper discusses a control method that achieves high weighted efficiency in solar microinverters. A challenge in microinverters is to achieve high efficiency over a range of output powers. To address this challenge, the proposed controller presents two primary benefits that enable such an efficiency profile, a switching frequency that scales with power, and a low peak current that enables efficient magnetic design of the inductor. At high powers, the switching frequency increases to minimize the root-mean-square (rms) current, and at low powers, the switching frequency decreases to minimize the switching loss. Since the peak inductor current is low, the inductor may be designed with fewer turns of wire, or with lower flux density, and is thus highly efficient. The proposed constant peak current switching scheme is implemented by a cycle-by-cycle predictive controller that uses a fast integrator to control the switching period, achieving high bandwidth and stability. This controller senses only the peak inductor current and, therefore, does not require expensive average current sensors. We demonstrate a low-cost inverter prototype with a 300-W solar panel. The prototype uses standard silicon devices and a small inductor of 360 μH to achieve a weighted efficiency of 99.15%.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Bus Voltage Control With Zero Distortion and High Bandwidth for
           Single-Phase Solar Inverters
    • Authors: Levron; Y.;Canaday, S.;Erickson, R.W.;
      Pages: 258 - 269
      Abstract: Single-phase inverters must include an energy storage device, typically a high-voltage bus capacitor, to match the inverter constant input power to its pulsating output power. Because of its increased cost, the size of this bus capacitor must be minimized. However, when the bus capacitor is small, the bus voltage includes a high ripple at the ac line second harmonic frequency, which causes harmonic distortion. The bus voltage controller must filter this ripple, while regulating the bus voltage efficiently during transients, and must therefore balance a tradeoff between two conflicting constraints, low-harmonic distortion and high bandwidth. This paper analyzes this tradeoff, and proposes a new control method for solving it without using addition hardware. Instead of reducing the distortion by lowering the loop gain, the new controller employs a digital FIR filter that samples the bus voltage at an integer multiple of the second harmonic frequency. The filter presents a notch that removes the second harmonic ripple, enabling a design that operates with zero distortion and high bandwidth simultaneously, and is suitable for inverters with small bus capacitors. The proposed controller is tested on a microinverter prototype with a 300-W photovoltaic panel and a 20-μF bus capacitor.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Power Electronic Circuits for Magnetic Energy Harvesters
    • Authors: Moon; J.;Leeb, S.B.;
      Pages: 270 - 279
      Abstract: Compared to many other energy harvesting schemes, harvesting energy from magnetic fields offers potential advantages for energy extraction and sensing. A magnetic energy harvester provides great flexibility for sensors and monitoring applications for condition-based monitoring of electromagnetic actuators, including vibration and thermal monitoring. A core must be managed or operated with carefully timed saturation to ensure maximum power extraction, a complex problem given the nonlinear saturation characteristics of a magnetic core [1]. This paper presents a simulator-friendly “circuit model” for a magnetic core, and uses this model to design and demonstrate several power electronic circuit solutions for harvesting energy. The circuit model has an excellent accuracy to represent the core regardless of the level of saturation. The design techniques to enhance power harvest are proposed, and verified through simulation and experiments, substantially boosting the amount of power harvest.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Modeling and Analysis of a Fast and Robust Module-Integrated Analog
           Photovoltaic MPP Tracker
    • Authors: Maity; S.;Sahu, P.K.;
      Pages: 280 - 291
      Abstract: Analog circuitry-based photovoltaic (PV) maximum power point (MPP) tracking (MPPT) technique is attractive due to its low cost and capability of easy integration with normal dc–dc switching converters. However, realization of classical digital MPPT algorithms using analog circuitries is a challenging task. It necessarily requires to store the information of module voltage/current and power in order to find the desired MPP. While at the same time, improper design of digital MPPT controllers may cause poor tracking performances or limit cycle oscillations to manifest, which are generally seen as being undesirable. This paper proposes a fast and robust analog PV MPP tracker without imposing any external control or perturbation. The fast dynamic performances with absolute robustness are ensured here by integrating the concepts of Utkin's equivalent sliding mode control law and fast-scale stability analysis of actual switched converter systems. Moreover, the superiority of the proposed MPP tracker (in terms of high-tracking performances) over classical ones, and its impact in series-connected converters configuration are analytically demonstrated through the procedure developed in this paper. Finally, the analytical results have been validated by means of simulations and experiments.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Power Balance of Cascaded H-Bridge Multilevel Converters for Large-Scale
           Photovoltaic Integration
    • Authors: Yu; Y.;Konstantinou, G.;Hredzak, B.;Agelidis, V.G.;
      Pages: 292 - 303
      Abstract: Multilevel cascaded H-bridge converters are promising candidates for large-scale photovoltaic power plants. They allow direct connection to medium-voltage distribution networks without the presence of bulky line frequency power transformers. Owing to the stochastically variable nature of irradiance level, ambient temperature, and other factors, power levels in the three phases are expected to be unequal. The power imbalance condition creates unexpected problems with this topology, which was initially designed to operate under balanced power conditions. To deal with this issue, the paper proposes three novel zero-sequence injection methods as an expansion to the conventional zero-sequence injection method. Results obtained from simulations and a 430-V 8-kW three-phase seven-level cascaded H-bridge prototype are presented to verify the effectiveness and feasibility of the proposed methods.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Distributed Architecture Based on Microbank Modules With
           Self-Reconfiguration Control to Improve the Energy Efficiency in the
           Battery Energy Storage System
    • Authors: Zhang; Z.;Cai, Y.;Zhang, Y.;Gu, D.;Liu, Y.;
      Pages: 304 - 317
      Abstract: This paper proposes a new distributed battery energy architecture based on the microbank module (MBM) for dc microgrids. The benefits of the proposed architecture include: 1) no voltage sharing problem and no overcharge/overdischarge problem; 2) high compatibility and reliability; 3) high energy utilization efficiency; 4) reduced volume and weight of the battery management system (BMS). The proposed MBM consists of a microbidirectional dc/dc converter, a micro-BMS and a cell bank. Moreover, taking advantage of the battery recovery effect, a self-reconfiguration discharge strategy is also proposed to further enhance the battery performance and discharge efficiency of the new battery energy storage system (BESS). To optimize the proposed control, an efficiency analytical model considering the battery recovery effect is proposed using the curve fitting method. Owing to the bidirectional capability, soft switching capability and high efficiency, the dual active bridge (DAB) converters are chosen as the microbidirectional dc/dc converters. A hybrid modulation strategy with variable switching frequency combining the conventional phase-shift modulation and triangular current modulation is proposed for the DAB converter to reduce the dominant loss and improve the efficiency in wide load range based on the minimum loss model. A 1.5-kW experimental testing platform consisting of four MBMs and four 12 V/100 Ah lithium battery modules was built to verify the proposed architecture with the control and the proposed model. The experimental results show that the discharge time of the proposed distributed BESS is increased significantly under wide operation condition with the self-reconfiguration control. The discharge efficiency of the BESS is improved by 7.1% with the idling time of 5 min under the power level of 1.5 kW.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A High-Efficiency Flyback Micro-inverter With a New Adaptive Snubber for
           Photovoltaic Applications
    • Authors: Rezaei; M.A.;Lee, K.;Huang, A.Q.;
      Pages: 318 - 327
      Abstract: Based on the hybrid operation of interleaved flyback micro-inverter in discontinuous and boundary conduction modes (DCM and BCM), a novel adaptive snubber is proposed in this paper. The proposed snubber limits the drain-to-source voltage overshoot of the flyback's main switch during the turn-off process, enabling the use of lower voltage MOSFETs. It also recovers the stored energy in the leakage inductance of the flyback transformer and provides soft switching for the main flyback switch by limiting the rising slope of the MOSFET voltage during the turn-off process resulting in higher efficiency. Exploiting the natural resonant of the flyback converter in BCM, the adopted controller provides ZVS and ZCS for the main switch during the BCM operation. The operation of the flyback micro-inverter with associated controllers is analytically studied, and considerations for an optimum design aiming to higher efficiency are presented. Performance of the flyback micro-inverter with the proposed adaptive snubber and the corresponding controllers is experimentally verified based on a 250W interleaved flyback micro-inverter hardware setup.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • High-Frequency-Link-Based Grid-Tied PV System With Small DC-Link Capacitor
           and Low-Frequency Ripple-Free Maximum Power Point Tracking
    • Authors: Shi; Y.;Li, R.;Xue, Y.;Li, H.;
      Pages: 328 - 339
      Abstract: This paper proposes a grid-tied photovoltaic (PV) system consisting of modular current-fed dual-active-bridge (CF-DAB) dc–dc converter with cascaded multilevel inverter. The proposed converter allows a small dc-link capacitor in the three-phase wye-connected PV system; therefore, the system reliability can be improved by replacing electrolytic capacitors with film capacitors. The low-frequency ripple-free maximum power point tracking (MPPT) is also realized in the proposed converter. First of all, to minimize the influence resulting from reduced capacitance, a dc-link voltage synchronizing control is developed. Then, a detailed design of power mitigation control based on CF-DAB dynamic model is presented to prevent the large low-frequency voltage variation propagating from the dc-link to PV side. Finally, a novel variable step-size MPPT algorithm is proposed to ensure not only high MPPT efficiency, but also fast maximum power extraction under rapid irradiation change. A downscaled 5-kW PV converter module with a small dc-link capacitor was built in the laboratory with the proposed control and MPPT algorithm, and experimental results are given to validate the converter performance.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Bidirectional Resonant DC–DC Step-Up Converters for Driving
           High-Voltage Actuators in Mobile Microrobots
    • Authors: Tang; Y.;Khaligh, A.;
      Pages: 340 - 352
      Abstract: Electroactive polymer (EAP) actuators have been investigated to convert electrical energy into mechanical deformation in autonomous microrobots. The use of dielectric EAP actuators comes with several challenges to address requirements such as high excitation voltages, explicit driving signals, and low conversion efficiency. External bulky and heavy power sources are used to generate and provide required excitation voltages. The development of a miniature, high voltage gain, and highly efficient power electronic interface is required to overcome such challenges and enable autonomous operation of miniature robots. In this paper, a bidirectional single-stage resonant dc–dc step-up converter is introduced and developed to efficiently drive high-voltage EAP actuators in mobile microrobots. The converter utilizes resonant capacitors and a coupled inductor as a soft-switched LC network to step up low input voltage. High-frequency soft-switching operation owing to LC resonance allows small footprint of the circuit without suffering from switching losses, which in turn increases the efficiency. The circuit is capable of generating explicit high-voltage actuation signals, with capability of recovering unused energy from EAP actuators. A 4-mm × 8-mm, 100-mg, and 600-mW prototype has been designed and fabricated to drive an in-plane gap-closing electrostatic inchworm motor. Experimental validations have been carried out to verify the circuit's ability to step up voltage from 2 to 100 V and generate two 1-kHz, 100-V driving voltages at 2-nF capacitive loads.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Cascade Point of Load DC–DC Converter With a Novel Phase Shifted
           Switched Capacitor Converter Output Stage
    • Authors: Challa; S.R.;Kastha, D.;Patra, A.;
      Pages: 353 - 368
      Abstract: This paper presents the analysis, design, modeling and control of a cascaded two-stage step-down dc–dc converter with a conventional synchronous buck converter in the first stage and a new phase shifted switched capacitor (PSSC) buck converter in the second stage. Higher efficiency and higher power density compared to the conventional multiphase buck converter are the prominent features of the proposed architecture which make it suitable as a point of load converter, widely used in powering computing, communication and networking equipment. The first stage buck converter is operated at high switching frequency with extended duty ratio and is designed for high efficiency. The second stage PSSC converter with low input voltage attains high efficiency when operated at a fixed conversion ratio with low switching frequency and a simple constant current charging technique. A laboratory prototype converter achieved a peak efficiency of 86.8% at 30 -A load current while operating at 12 -V input voltage and 1.3 -V output voltage. The capacitor-based output power stage drastically reduces the number of inductors compared to the multiphase buck converter. A low frequency small signal model of the converter and a state feedback controller for the output voltage are developed analytically. The closed-loop transient performance of the converter using this state feedback controller is also verified experimentally.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Tradeoffs Aware Design Procedure for an Adaptively Biased Capacitorless
           Low Dropout Regulator Using Nested Miller Compensation
    • Authors: Maity; A.;Patra, A.;
      Pages: 369 - 380
      Abstract: An adaptively biased, low dropout regulator (AB-LDR) that uses the nested Miller type frequency compensation has been explored in the literature for system-on-chip applications. However, those are mostly focused to solve only specific issues without accounting for all the design tradeoffs. Due to this, additional components/circuits are needed to mitigate the issues like Q -peaking and poor dynamic response in capacitorless condition. In this paper, the various design tradeoffs particularly relevant to the nested Miller compensated regulator architecture, are clearly brought out. Then a detailed design procedure for the same architecture is proposed to achieve a low quiescent current, wide dynamic range, desired dynamic response and a high current efficiency over a given load range. An AB-LDR has been implemented in standard 0.18- \mu m CMOS technology to validate the effectiveness of the proposed approach. Experimental results show a very good agreement with the theoretical analysis.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Multi-input Step-Up Converters Based on the Switched-Diode-Capacitor
           Voltage Accumulator
    • Authors: Hou; S.;Chen, J.;Sun, T.;Bi, X.;
      Pages: 381 - 393
      Abstract: This paper introduces the application of a switched-diode-capacitor voltage accumulator (SDCVA) on conventional boost converter. This study aims to obtain two different kinds of multi-input step-up converters with high voltage gains, low component stresses, low ripples, simple control, and high conversion efficiencies: one is based on the parallel SDCVA and the other based on the serial SDCVA. The double-input step-up converter based on the parallel SDCVA and the double-input step-up converter based on the serial SDCVA are, respectively, taken as an example to do theoretical analysis, including operating principles and performance analyses when they work individually and simultaneously. The two proposed converters are implemented with a voltage closed-loop control at the switching frequency of 30 kHz. Experimental results obtained from the implemented prototypes are provided to validate the feasibility and effectiveness of the proposed converters.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Steady-State Analysis and Design of Class-D ZVS Inverter at Any Duty Ratio
    • Authors: Wei; X.;Sekiya, H.;Nagashima, T.;Kazimierczuk, M.K.;Suetsugu, T.;
      Pages: 394 - 405
      Abstract: This paper presents steady-state analytical expressions of the class-D zero-voltage switching inverter at any duty ratio along with a design example. The obtained expressions include stead-state voltage and current waveforms, output power capability, peak switch voltage, peak switch current, output power, and power conversion efficiency as functions of the duty ratio. Additionally, switching-timing allowance due to antiparallel diodes of switching devices can be predicted from the analytical results. The analytical expressions are verified by showing quantitative agreements with PSpice simulations and circuit experiments.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Novel Transformer-less Interleaved Four-Phase Step-Down DC Converter
           With Low Switch Voltage Stress and Automatic Uniform Current-Sharing
    • Authors: Chuang; C.;Pan, C.;Cheng, H.;
      Pages: 406 - 417
      Abstract: In this paper, we propose a novel transformer-less direct current (dc) converter that features low switch voltage stress and automatic uniform current sharing. An interleaved four-phase voltage divider operating from a 400 V dc bus is used to achieve a high step-down conversion ratio with a moderate duty ratio. Based on the capacitive voltage division, the proposed converter achieves two major objectives, i.e., increased voltage conversion ratio, due to energy storage in the blocking capacitors, and reduced voltage stress of active switches and diodes. As a result, the proposed converter permits the use of lower voltage rating MOSFETs to reduce both switching and conduction losses, thereby improving the overall efficiency. In addition, due to the charge balance of the capacitors, the proposed converter enables automatic uniform current sharing of the interleaved phases without adding extra circuitry or complex control methods. The operation principles and performance analyses of the proposed converter are presented, and its effectiveness is verified by a 500 W output power prototype circuit that converts 400 V input voltage into 24 V output voltage.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A DCM-Only Buck Regulator With Hysteretic-Assisted Adaptive
           Minimum-On-Time Control for Low-Power Microcontrollers
    • Authors: Fu; W.;Tan, S.T.;Radhakrishnan, M.;Byrd, R.;Fayed, A.A.;
      Pages: 418 - 429
      Abstract: A 40-mA buck regulator operating in the inherently stable Discontinuous Conduction Mode (DCM) for the entire load range is presented. A pulse frequency modulation control scheme is implemented using a proposed hysteretic-assisted adaptive minimum-on-time controller to automatically adapt the regulator to a wide range of operating scenarios in terms of input, output, and passive component values while ensuring compensationless DCM operation with minimized inductor peak current. Thus, compact silicon area, low quiescent current, high efficiency, and robust performance across all possible scenarios can be achieved without any calibration. Moreover, power gating is employed in the analog circuits of the proposed controller to further improve efficiency at sub-mA loads. The regulator is integrated within a low-power microcontroller in 90-nm CMOS to power its digital core while allowing maximum flexibility in the powering options of the microcontroller and the choice of the passive components. It occupies 0.1 mm2 and achieves 92% peak efficiency, and 78.5% and 86% efficiency at 200-μA and 40-mA loads, respectively. It handles an input in the range of 1.8–4.2 V, an output in the range of 0.9–1.4 V, an inductor in the range of 4.7–10 μH, and an output capacitor in the range of 2.2–10 μF without any calibration or reoptimization.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Study on the Single-Stage Forward-Flyback PFC Converter With QR Control
    • Authors: Xie; X.;Li, J.;Peng, K.;Zhao, C.;Lu, Q.;
      Pages: 430 - 442
      Abstract: The single-stage forward-flyback power factor correction converter with quasi-resonant (QR) control is studied in this paper. This converter merges flyback converter and forward converter through a common transformer. Only the flyback subconverter works when the input voltage is lower than the reflected output voltage while both the flyback subconverter and the forward subconverter operate to share the output power in the rest region. The dead zones which exist in the ac input current of traditional forward converter are eliminated and high power factor can be achieved. Two different QR control schemes have been studied. Detailed analysis, optimal design considerations, and comparison for these two QR control modes are provided. Finally, two 120 W experimental prototypes for LED driver were built up to verify the theoretical analysis.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Switching Frequency Stabilization Techniques for Adaptive On-Time
           Controlled Buck Converter With Adaptive Voltage Positioning Mechanism
    • Authors: Tsai; C.;Chen, B.;Li, H.;
      Pages: 443 - 451
      Abstract: Unpredictable continuous conduction mode switching frequency variation that occurs commonly in ripple-based control can lead to serious electronic–magnetic interface noise problems and thus increase the effort required for designing noise filters. Sensorless load current correction and dynamic tolerance window techniques are proposed in this paper to reduce the frequency variations caused by conduction losses without employing complicated circuits such as phase-locked loop or current sensors. The proposed dc–dc buck converter with input voltage ranging from 2.7 to 3.6 V and an output voltage between 1.0 and 1.2 V was fabricated using a standard 0.18-μm CMOS process, and the converter achieved excellent adaptive voltage positioning function. Experimental results show that the switching frequency variation improved approximately 60% over traditional techniques in constant on-time control when the load current was changed from 150 to 1000 mA. The measurement results also show that frequency variation across the entire input/output and loading ranges was lowered to only ±2.6%. The maximum power efficiency was 88.2% at 150 mA with an input voltage of 2.7 V.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Power-Electronics-Based Energy Management System With Storage
    • Authors: Oriti; G.;Julian, A.L.;Peck, N.J.;
      Pages: 452 - 460
      Abstract: This paper demonstrates the functionality of a power-electronics-based energy management system (EMS). The EMS includes batteries and a digitally controlled single-phase voltage source inverter (VSI), which can be controlled as a current source or a voltage source depending on the status of the ac grid and the user's preference. The EMS guarantees that the critical loads are powered when the ac grid fails; in which case, the VSI is controlled as a voltage source. It also accomplishes peak power control by supplying battery power to the local loads while they are powered by the ac grid if the loads get large. The electricity cost savings accomplished by peak shaving are estimated. The EMS functionality is demonstrated by experimental measurements on a laboratory prototype. The control architecture and logic embedded in the EMS are discussed in detail.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Dual Switches DC/DC Converter With Three-Winding-Coupled Inductor and
           Charge Pump
    • Authors: Tang; Y.;Fu, D.;Kan, J.;Wang, T.;
      Pages: 461 - 469
      Abstract: In order to obtain a high step-up voltage gain, high-efficiency converter, this paper proposed a dual switches dc/dc converter with three-winding-coupled inductor and charge pump. The proposed converter composed of dual switches structure, three-winding-coupled inductor, and charge pump. This combination facilitates realization of high step-up voltage gain with a low voltage/current stress on the power switches. Meanwhile, the voltage across the diodes is low and the diode reverse-recovery problem is alleviated by the leakage inductance of the three-winding-coupled inductor. Taking all these into consideration, the efficiency can be high. This paper illustrated the operation principle of the proposed converter; discussed the effect of leakage inductance on voltage gain; the conditions of zero current shutting off of the diodes are illustrated; the voltage and current stress of the power devices are shown; a comparison between the performance of the proposed converter and previous high step-up converters was conducted. Finally, a prototype rated at 500 W has been established, and the experimental results verify the correctness of the analysis.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Analytical Switching Cycle Modeling of Bidirectional High-Voltage Flyback
           Converter for Capacitive Load Considering Core Loss Effect
    • Authors: Huang; L.;Zhang, Z.;Andersen, M.A.E.;
      Pages: 470 - 487
      Abstract: With the advancement of material science, various smart materials with intrinsic capacitive property are emerging. The high-voltage (HV) power electronics converters with bidirectional energy flow functionality for supplying the capacitive load are highly demanded. A switching cycle-based analytical model of an HV bidirectional converter driving capacitive load is beneficial in thoroughly understanding the operational behavior, investigating the energy efficiency, and optimizing the design. In this paper, an HV bidirectional flyback converter for capacitive load is generally discussed in terms of configuration and working principle. Considering the parasitic elements as well as the core loss effect, the converter is modeled with analytical formulas for one switching cycle. The comparison between the model-based calculation results and prototype experiments-based measurement results are used to validate the analytical model.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Operating Conditions Monitoring for High Power Density and Cost-Effective
           Resonant Power Converters
    • Authors: Sarnago; H.;Lucia, O.;Navarro, D.;Burdio, J.M.;
      Pages: 488 - 496
      Abstract: Resonant power conversion is a key enabling technology for many high-performance and high-efficiency systems. Induction heating is an example of such systems, which outperforms conventional heating technologies, leading to a wide spectrum of industrial, domestic, and medical applications. In order to ensure the proper operation of the resonant converter, accurate converter operation monitoring techniques are required. This paper proposes an effective monitoring technique based on the measurement of the resonant capacitor voltage. The proposed monitoring system provides essential information regarding the output power, soft-switching conditions, and input voltage, while featuring a cost-effective implementation. The proposed technique is validated through an FPGA-controlled resonant power converter applied to induction heating, proving the feasibility of this proposal.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Magnetizing Curve Estimation of Induction Motors in Single-Phase
           Magnetization Mode Considering Differential Inductance Effect
    • Authors: Ruan; J.;Wang, S.;
      Pages: 497 - 506
      Abstract: To obtain an accurate magnetizing curve of induction motors at standstill, including both field-weakening region and saturated region, a novel method for estimation of mutual inductance L_{m} is proposed. At first, the reasons causing error of L_{m} identified by conventional ac-current-injection-based method, i.e., fluctuation of static L_{m} and differential inductance effect, are clarified in a theoretical view. To solve the problem, a continuous ac excitation of customized low frequency, with dc offset, is designed to excite the motor in single-phase mode. While dc offset with configurable amplitudes is used to fix the saturation level and restrain variation of static L_{m} , ac excitation maintains identifiability of the inductance. After the estimated L_{m} is retrieved from stator-side reactance, a direct numerical-integration method is proposed to effectively correct the differential inductance effect. The influence of injection frequency is rigorously investigated, which is also a key point for successful estimation. Both simulation and experiments have been implemented to demonstrate the feasibility and validity of the proposed method.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Design and Control of Modular Multilevel Converters for Battery Electric
    • Authors: Quraan; M.;Yeo, T.;Tricoli, P.;
      Pages: 507 - 517
      Abstract: New advanced power conversion systems play an essential role in the extension of range and life of batteries. This paper proposes a new modular multilevel converter with embedded electrochemical cells that achieves very low cell unbalancing without traditional balancing circuits and a negligible harmonic content of the output currents. In this new topology, the cells are connected in series by means of half-bridge converters, allowing high flexibility for the discharge and recharge of the battery. The converter features a cell balancing control that operates on each individual arm of the converter to equalize the state of charge of the cells. The paper shows that the proposed control does not affect the symmetry of the three-phase voltage output, even for significantly unbalanced cells. The viability of the proposed converter for battery electric vehicles and the effectiveness of the cell balancing control are confirmed by numerical simulations and experiments on a kilowatt-size prototype.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • An Integrated Bootstrap Diode Emulator for 600-V High Voltage Gate Drive
           IC With P-Sub/P-Epi Technology
    • Authors: Zhu; J.;Sun, W.;Zhang, Y.;Lu, S.;Shi, L.;Zhang, S.;Su, W.;
      Pages: 518 - 523
      Abstract: An integrated bootstrap diode emulator, including the high voltage field-effect-transistor (HV-FET), the gate control circuit and the back-gate control circuit, is experimentally proposed base on p-sub/p-epi bipolar-CMOS-DMOS technology for the first time. By adopting the gate and the back-gate control circuits, the charging time of the bootstrap capacitor can be improved by about 27% without any latch-up issues. The measured blocking voltage of the proposed HV-FET is higher than 750 V, which can be embedded in the isolation structure without sacrificing the chip area and is suitable for 600-V motor control system application. Finally, a 600-V-class high voltage gate drive IC with the proposed integrated bootstrap diode emulator is fabricated. The chip size is about 2.1 mm2 and the charging duration is about 80 μs with 1-μF bootstrap capacitor.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Piezoelectric Filter Module Used in Harmonics Elimination for
           High-Efficiency Piezoelectric Transformer Driving
    • Authors: Ju; B.;Shao, W.;Feng, Z.;
      Pages: 524 - 532
      Abstract: Switching driving, such as pulse width modulation, has been used in many power circuits because of its high efficiency. However, given the capacitance of a piezoelectric transformer (PT) for high harmonics in a square waveform, using switching technology directly in a driver circuit is difficult without an inductance linked with the PT. This paper proposes a design of a piezoelectric filter module for eliminating harmonic frequencies in the driving of a PT. Compared with a traditional inductor filter, the performance, cost, and space advantages make the module a wiser choice. The particular design of several PFs fabricated on one piece of piezoelectric plate has future integration potential with the transformer. The third harmonic filtering experiment shows that the module exhibits excellent performance on the elimination of harmonics and improvement of the whole converter's efficiency, making the large inductor for wide-range damping of harmonics unnecessary. Efficiency analyses for a simplified push–pull power amplifier model prove the existence of an optimum output waveform for a tradeoff consideration on the circuit efficiency and driving complexity of a PT. This study offers detailed guidance for the future development of novel converter circuits.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Two-Stage Matrix Converter Based on Third-Harmonic Injection Technique
    • Authors: Wang; H.;Su, M.;Sun, Y.;Yang, J.;Zhang, G.;Gui, W.;Feng, J.;
      Pages: 533 - 547
      Abstract: Due to the merits of sinusoidal input currents and excellent conversion efficiency, buck-type active third-harmonic injection converters have received increasing attention in recent years. However, three major problems of these converters still exist in theory and practice. First, the existence of the dc-link capacitor, utilized by early researchers, causes inrush transient and distorts the input currents. Second, in some specific situations, such as wind energy conversion system and flexible ac transmission system, these converters' capabilities of generating input reactive power need sufficient improvements. Third, proper selection of the third-harmonic injection inductor is the key challenge to implement these converters, since the inductor affects not only the current ripple but also the tracking performance of the third-harmonic current. To solve these problems, this paper studies the two-stage matrix converter with third harmonics injection and demonstrates that the dc-link capacitor can be removed by bidirectional implementation and proper control of the rectifier. Then, an algorithm enhancing the input reactive power capability is developed. Thus, sinusoidal input currents are achieved and the reactive power control range is extended significantly. Moreover, the design criteria of the third-harmonic injection inductor are discussed. Finally, the proposed method is verified by simulation and experimental results.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Novel Experimental Identification Method for a Supercapacitor Multipore
           Model in Order to Monitor the State of Health
    • Authors: German; R.;Hammar, A.;Lallemand, R.;Sari, A.;Venet, P.;
      Pages: 548 - 559
      Abstract: Supercapacitors (SCs) impedance modeling represents one important key to get information for SCs health monitoring and simulation. As a matter of fact, SCs behavior is dependent on various parameters such as pore size distribution of electrodes, electrolyte state, temperature, aging, etc. We propose in this study to model SC taking into account physical considerations. Basing on the theory on homogenous structure impedance, we first define the single pore model using the uniform size of pores distribution. In the second step, we attempt to generalize this circuit model considering an electrode with different pores sizes or different penetrabilities of the pores. This model called multipore (MP) model (or multipenetrability model) has been developed by our laboratories. This model allows analyzing the behavior of SC by modeling each group of electrode pores as a branch of an electrical equivalent circuit. This paper is the first in the literature to give a simple and reproducible method for MP model parameters identification. The validity of the identification method will also be verified at different SC aging rates thanks to experimental aging tests.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Systematic Approach to Modeling Impedances and Current Distribution in
           Planar Magnetics
    • Authors: Chen; M.;Araghchini, M.;Afridi, K.K.;Lang, J.H.;Sullivan, C.R.;Perreault, D.J.;
      Pages: 560 - 580
      Abstract: Planar magnetic components using printed circuit board (pcb) windings are attractive due to their high repeatability, good thermal performance, and usefulness for realizing intricate winding patterns. To enable higher system integration at high switching frequency, more sophisticated methods that can rapidly and accurately model planar magnetics are needed. This paper develops a systematic approach to modeling impedances and current distribution in planar magnetics based on a lumped circuit model named as the modular layer model (MLM). Stacked pcb layers are modeled as repeating modular impedance networks, with additional modular impedances representing the magnetic core, air gaps, and vias. The model captures skin and proximity effects, and enables accurate predictions of impedances, losses, stored reactive energy, and current sharing among windings. The MLM can be used to simulate circuits incorporating planar magnetics, to visualize the electromagnetic fields, and to extract parameters for magnetic models by simulations, among many other applications. The modeling results are checked with results of previous theories and finite-element-modeling approaches, with good matching presented. A group of planar magnetic devices, including transformers and inductors with various winding patterns, are prototyped, and measured to validate the proposed approach and clarify the boundaries of its applicability.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Characterization, Modeling, and Analysis of Organic Light-Emitting Diodes
           With Different Structures
    • Authors: Chen; H.;Choy, W.C.H.;Hui, S.Y.R.;
      Pages: 581 - 592
      Abstract: This paper demonstrates that organic light-emitting diodes (OLEDs) of different structures can be characterized and modeled using a combination of the photo–electro–thermal (PET) theory and spectral power distribution modeling. The photometric, electrical, thermal, and chromatic properties of OLED devices are incorporated into a model framework so that the performance of the OLED of different structures can be compared. A concept of luminance uniformity over the OLED surfaces is also introduced for comparing OLED with large surface areas. Experimental results are included to verify the OLED models and compare the characteristics of two different OLED samples. Based on the same PET framework, some differences of OLEDs and inorganic LEDs are addressed and discussed.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Avoiding Si MOSFET Avalanche and Achieving Zero-Voltage Switching for
           Cascode GaN Devices
    • Authors: Huang; X.;Du, W.;Lee, F.C.;Li, Q.;Liu, Z.;
      Pages: 593 - 600
      Abstract: The cascode structure is widely used for high-voltage normally-on wide-bandgap devices. However, the interaction between the high-voltage normally-on device and the low-voltage normally-off Si MOSFET may induce undesired features. This paper analyzes the voltage distribution principle during the turn-off transition as well as the zero-voltage-switching (ZVS) principle during the turn-on transition for cascode GaN devices. The capacitance mismatch between high-voltage normally-on GaN switch and the low-voltage Si MOSFET causes the Si MOSFET to avalanche, and internal high-voltage GaN switch lose the ZVS condition. This issue must be solved in consideration of both power loss and reliability. A simple and effective solution is proposed by adding an extra capacitor to compensate the capacitance mismatch, thereby avoiding Si MOSFET avalanche and achieving true ZVS for cascode GaN devices. The benefits and small penalty of this solution are analyzed in detail. The theoretical analysis is validated by experiments, which are implemented based on a 600-V cascode GaN device. The experiment shows that the proposed method improves the 600-V cascode GaN devices performance significantly in high-frequency applications. The analysis and proposed solution are also applicable to other cascode devices.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Deadtime Effect on GaN-Based Synchronous Boost Converter and Analytical
           Model for Optimal Deadtime Selection
    • Authors: Han; D.;Sarlioglu, B.;
      Pages: 601 - 612
      Abstract: It is widely acknowledged that gallium nitride (GaN)-based power switching devices are superior to conventional silicon (Si) devices in terms of lower semiconductor loss and faster switching speed. However, the deadtime related losses in GaN HEMT-based converters can be detrimental if not optimized, especially when operating at very high switching frequencies. This paper proposes an original analytical model for deadtime optimization for the GaN converters. The proposed model is more accurate than conventional deadtime optimization methods used in Si converters. A GaN-based synchronous boost converter is used as a case study. Circuit simulation and experimental tests are successfully performed to verify the analysis and proposed model.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Transient Hygrothermal-Response of Power Modules in Inverters—The
           Basis for Mission Profiling Under Climate and Power Loading
    • Authors: Bayerer; R.;Lassmann, M.;Kremp, S.;
      Pages: 613 - 620
      Abstract: The number of outdoor applications of power electronics is growing. Therefore, mission profiling with respect to climate conditions has become a new field of interest. The response of moisture inside power electronics can be simulated by the use of an equivalent circuit. It consists of variable and controlled resistors and capacitors to describe diffusivity, permeability, and storage in polymers. Here, voltages represent the concentration of moisture in air or polymers. Such R–C networks allows us to describe 2-D- and 3-D-effects. The coupling to the thermal equivalent networks can be done by voltage outputs, e.g., temperatures. The coupled thermal- and hygro-sub-circuit lead to the overall hygrothermal equivalent circuit. This circuit allows simulating moisture levels based on climate conditions and heating due to the operation of power electronics. Examples demonstrate the possibility that humidity inside cabinets exceeds the ambient conditions due to the desorption of moisture from the heated polymers. It is also demonstrated that condensation of moisture can occur during day and night cycles. Failure models need to be established to conclude with lifetime calculations based on this method.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Influences of Device and Circuit Mismatches on Paralleling Silicon Carbide
    • Authors: Li; H.;Munk-Nielsen, S.;Wang, X.;Maheshwari, R.;Beczkowski, S.;Uhrenfeldt, C.;Franke, W.;
      Pages: 621 - 634
      Abstract: This paper addresses the influences of device and circuit mismatches on paralleling the silicon carbide (SiC) MOSFETs. Comprehensive theoretical analysis and experimental validation from paralleled discrete devices to paralleled dies in multichip power modules are first presented. Then, the influence of circuit mismatch on paralleling SiC MOSFETs is investigated and experimentally evaluated for the first time. It is found that the mismatch of the switching loop stray inductance can also lead to on-state current unbalance with inductive output current, in addition to the on-state resistance of the device. It further reveals that circuit mismatches and a current coupling among the paralleled dies exist in a SiC MOSFET multichip power module, which is critical for the transient current distribution in the power module. Thus, a power module layout with an auxiliary source connection is developed to reduce such a coupling effect. Finally, simulations and experimental tests are carried out to validate the analysis and effectiveness of the developed layout.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • An Analytical Switching Process Model of Low-Voltage eGaN HEMTs for Loss
    • Authors: Wang; K.;Yang, X.;Li, H.;Ma, H.;Zeng, X.;Chen, W.;
      Pages: 635 - 647
      Abstract: This paper proposes an improved analytical switching process model to calculate the switching loss of low-voltage enhancement-mode Gallium Nitride high-electron mobility transistors (eGaN HEMTs). The presented eGaN HEMTs models are more or less derived from silicon MOSFETs models, whereas eGaN HEMTs are different from three aspects: higher switching speed, much more reduced parasitic inductance in switching loop, and absence of reverse recovery. Applying the traditional model to eGaN HEMTs results in inaccurate prediction of switching waveforms and losses. The proposed model considers the effect of low-parasitic inductances, nonlinearity of junction capacitances, and nonlinearity of transconductance. The turn-on and turn-off switching processes are described in detail and the resulting equations can be easily solved. The accuracy of the proposed model is validated by comparing the predicted switching waveforms and converter's efficiency with the experimental results, respectively. Based on the analytical model, the effects of gate resistance, gate supply voltage, and parasitic inductances on switching losses are investigated. Meanwhile, a novel current measuring method based on magnetic coupling is proposed to measure the switching current waveform with improved accuracy.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Five Approaches to Deal With Problem of DC Offset in Phase-Locked Loop
           Algorithms: Design Considerations and Performance Evaluations
    • Authors: Golestan; S.;Guerrero, J.M.;Gharehpetian, G.B.;
      Pages: 648 - 661
      Abstract: The presence of the dc component in the phase-locked loop (PLL) input results in fundamental frequency oscillations in the phase and frequency estimated by the PLL. The removal of these oscillations is a challenging task because of their low frequency. The aim of this paper is to provide a detailed analysis of several approaches that little work has been conducted on their application for addressing the problem of dc offset in the PLL algorithms. These approaches include using the dq-frame delayed signal cancellation (DSC) operator and the notch filter (NF) as the PLL in-loop filtering stages, and using the \alpha \beta -frame DSC operator, the complex coefficient filter, and a cross-feedback network for blocking the dc offset before the PLL input. Design aspects of these methods are presented, some methods to enhance their performances are proposed, and their advantages and disadvantages are evaluated.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • FPGA-Based Experimental Investigation of a Quasi-Centralized Model
           Predictive Control for Back-to-Back Converters
    • Authors: Zhang; Z.;Wang, F.;Sun, T.;Rodriguez, J.;Kennel, R.;
      Pages: 662 - 674
      Abstract: Voltage source back-to-back power converters are widely used in grid-tied applications. This paper presents a quasi-centralized direct model predictive control (QC-DMPC) scheme for back-to-back converter control without a dc-link outer-loop controller. Furthermore, the QC-DMPC is experimentally compared with a conventional proportional-integration (PI) dc-link controller-based DMPC (PI-DMPC) scheme. For the QC-DMPC scheme, the dc-link voltage is directly controlled by a grid-side predictive controller using a dynamic reference generation concept and load-side power estimation. For the PI-DMPC scheme, the dc-link voltage is controlled by an external PI controller. Both schemes are implemented on a field programmable gate array (FPGA)-based platform. Effectiveness of the proposed QC-DMPC is verified by both simulation and experimental data. Moreover, FPGA implementation issues (resource usage and timing information), dc-link control performance, and robustness to parameter variation of the two DMPC schemes are compared in detail. The results emphasize that the QC-DMPC may outperform the PI-DMPC scheme in normal operation but with a slightly higher usage of FPGA resources. However, PI-DMPC scheme is more robust when parameter variations are considered.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Analysis of D-Q Small-Signal Impedance of Grid-Tied Inverters
    • Authors: Wen; B.;Boroyevich, D.;Burgos, R.;Mattavelli, P.;Shen, Z.;
      Pages: 675 - 687
      Abstract: This paper analyzes the small-signal impedance of three-phase grid-tied inverters with feedback control and phase-locked loop (PLL) in the synchronous reference (d-q) frame. The result unveils an interesting and important feature of three-phase grid-tied inverters – namely, that its q–q channel impedance behaves as a negative incremental resistor. Moreover, this paper shows that this behavior is a consequence of grid synchronization, where the bandwidth of the PLL determines the frequency range of the resistor behavior, and the power rating of the inverter determines the magnitude of the resistor. Advanced PLL, current, and power control strategies do not change this feature. An example shows that under weak grid conditions, a change of the PLL bandwidth could lead the inverter system to unstable conditions as a result of this behavior. Harmonic resonance and instability issues can be analyzed using the proposed impedance model. Simulation and experimental measurements verify the analysis.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Common-Mode Voltage Mitigation for Back-to-Back Current-Source Converter
           With Optimal Space-Vector Modulation
    • Authors: Guo; X.;Xu, D.;Wu, B.;
      Pages: 688 - 697
      Abstract: Common-mode voltage (CMV) problem is one of the most important issues for back-to-back current-source converters. In this paper, the theoretical analysis is presented to clarify that the system CMV mainly depends on the CMV difference between a rectifier and an inverter. And then, a new CMV mitigation technique is proposed. Different from the existing methods, the proposed method coordinates the active and zero vectors of both rectifier and inverter in the back-to-back current converter, instead of eliminating zero vectors or optimal selection of a zero vector. In this way, the CMV difference between a rectifier and an inverter is minimized. Consequently, the system CMV can be significantly mitigated. Finally, the experimental tests are carried out on a 10-kVA back-to-back current-source converter, and experimental results verify the effectiveness of the proposed method.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Predictive Duty Cycle Control of Three-Phase Active-Front-End Rectifiers
    • Authors: Song; Z.;Tian, Y.;Chen, W.;Zou, Z.;Chen, Z.;
      Pages: 698 - 710
      Abstract: This paper proposed an online optimizing duty cycle control approach for three-phase active-front-end rectifiers, aiming to obtain the optimal control actions under different operating conditions. Similar to finite-control set model predictive control strategy, a cost function previously constructed based on the desired control performance is adopted here, which is essential for the solving process of the optimizing problem. On the other hand, differently, with respect to the proposed strategy, duty cycle signals are optimized, instead of possible switching states. The determination of optimal duty cycles is made by predicting the effect of duty cycles on instantaneous current variations and minimizing the cost function. Due to the adoption of behavior prediction, the proposed controller inherits the excellent dynamic characteristics of predictive controllers. Moreover, the application of optimal duty cycles determined by cost function minimization automatically ensures optimum operations of converters within each sampling period. Improved transient and steady-state features of the proposed strategy are confirmed by experimental validations and in-depth comparisons with linear controllers, deadbeat predictive controllers, and finite-control set model predictive control strategies.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Zero-Sequence Current Suppression Strategy for Open Winding PMSG Fed by
           Semicontrolled Converter
    • Authors: Nian; H.;Zhou, Y.;Zeng, H.;
      Pages: 711 - 720
      Abstract: The open winding permanent magnet synchronous generator (PMSG) fed by semicontrolled converter takes the advantages of lower expense, simplified driving circuit, and reliable control realization. With a single dc supply, the implementation of open winding configuration in practical application could be much convenient. However, the common dc bus supplied configuration provides a zero-sequence current circuit unavoidably. In order to reduce the harmonic distortion, a zero-sequence current suppression scheme is proposed. The space vector pulse width modulation (SVPWM) technique is adopted to modulate the desired voltage reference in the three-dimensional (3-D) coordinate system by distributing duty cycles for active and zero vectors. With a comprehensive investigation on the semicontrolled configuration, the achievable modulation region for αβ0 voltage vector reference is analyzed. Finally, the zero-sequence current suppression method with 3-D-SVPWM technique is implemented in a 1 kW open winding PMSG experimental system.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Deadbeat Predictive Power Control of Single-Phase Three-Level
           Neutral-Point-Clamped Converters Using Space-Vector Modulation for
           Electric Railway Traction
    • Authors: Song; W.;Ma, J.;Zhou, L.;Feng, X.;
      Pages: 721 - 732
      Abstract: This paper presents an alternative approach to address the control and modulation problem of single-phase three-level converters applied in the high-speed railway electrical traction drive system. Following the principle of deadbeat predictive direct torque control of ac motors, this paper discusses an improved direct power control (DPC) method based on a deadbeat active and reactive power prediction technique. Comparing with the conventional PI-based DPC scheme, the proposed deadbeat predictive DPC scheme can provide these advantageous features: lower current harmonics and THD index, lower active and reactive power ripples, and fewer adjusted parameters. Moreover, compared with PI-based DPC with the PI parameters optimization, this approach can also easily obtain fast dynamic response but without the main voltage orientation. A single-phase three-level space vector pulse width modulation (SVPWM) with inherent neutral-point voltage balancing capability is adopted, which can be combined with DPC scheme as an overall control and modulation system. A series of simulation and experimental tests have been conducted to demonstrate an excellent performance of the deadbeat predictive DPC. In addition, the neutral-point-voltage balancing ability of the adopted SVPWM method has been verified.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A New Multiple-Frequency Small-Signal Model for High-Bandwidth Computer
           V-Core Regulator Applications
    • Authors: Hsiao; S.;Chen, D.;Chen, C.;Nien, H.;
      Pages: 733 - 742
      Abstract: A new multifrequency small-signal control model for high-bandwidth dc buck regulator is proposed. The describing function approach is taken to model the duty-cycle modulator, incorporating the effects of not only the modulating frequency f_{m} , the switching frequency f_{s} , and the two sideband frequencies f_{s}-f_{m} and f_{s}+ f_{m} . This model is significantly more accurate than the conventional average model and the recently proposed two-frequency model for applications with high control bandwidth-to-switching frequency ratio and high input-to-output voltage step down ratio, such as the v-core voltage regulators. The model is verified by simulations and experiments.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Delay-Dependent Stability of Single-Loop Controlled Grid-Connected
           Inverters with LCL Filters
    • Authors: Wang; J.;Yan, J.D.;Jiang, L.;Zou, J.;
      Pages: 743 - 757
      Abstract: LCL filters have been widely used for grid-connected inverters. However, the problem that how time delay affects the stability of digitally controlled grid-connected inverters with LCL filters has not been fully studied. In this paper, a systematic study is carried out on the relationship between the time delay and stability of single-loop controlled grid-connected inverters that employ inverter current feedback (ICF) or grid current feedback (GCF). The ranges of time delay for system stability are analyzed and deduced in the continuous s-domain and discrete z-domain. It is shown that in the optimal range, the existence of time delay weakens the stability of the ICF loop, whereas a proper time delay is required for the GCF loop. The present work explains, for the first time, why different conclusions on the stability of ICF loop and GCF loop have been drawn in previous studies. To improve system stability, a linear predictor-based time delay reduction method is proposed for ICF, while a time delay addition method is used for GCF. A controller design method is then presented that guarantees adequate stability margins. The delay-dependent stability study is verified by simulation and experiment.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Sliding-Mode Control for a Three-Phase Unity Power Factor Rectifier
           Operating at Fixed Switching Frequency
    • Authors: Guzman; R.;de Vicuna, L.G.;Morales, J.;Castilla, M.;Matas, J.;
      Pages: 758 - 769
      Abstract: This paper presents an improved variable hysteresis-band current-control in natural frame for a three-phase unity power rectifier. The proposed control algorithm is based on three decoupled sliding-mode controllers combined with three independent Kalman filters. The use of Kalman filters instead of a nonadaptive state observer improves the quality of the estimated signals in presence of noise, increasing the immunity of the control loop in noisy environments. To reduce drastically the computational load in the Kalman algorithm, a reduced bilinear model is derived which allows to use a Kalman filter algorithm instead of an extended Kalman filter. A fast output-voltage control is also presented which avoids output-voltage variations when a sudden change in the load or a voltage sag appears. Moreover, a fixed switching frequency algorithm is proposed which uses a variable hysteresis-band in combination with a switching decision algorithm, ensuring a switching spectrum concentrated around the desired switching frequency. The overall control proposal has been fully integrated into a digital signal processor. Selected experimental results are introduced to validate the theoretical contributions of this paper.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Split-Phase Control: Achieving Complete Soft-Charging Operation of a
           Dickson Switched-Capacitor Converter
    • Authors: Lei; Y.;May, R.;Pilawa-Podgurski, R.;
      Pages: 770 - 782
      Abstract: Switched-capacitor (SC) converters are gaining popularity due to their high power density and suitability for on-chip integration. Soft-charging and resonant techniques can be used to eliminate the current transient during the switching instances, and improve the power density and efficiency of SC converters. In this paper, we propose a split-phase control scheme that enables the Dickson converter to achieve complete soft-charging (or resonant) operation, which is not possible using the conventional two-phase control. An analytical method is extended to help in the analysis and design of split-phase controlled Dickson converters. The proposed technique and analysis are verified by both simulation and experimental results. An 8-to-1 step-down Dickson converter with an input voltage of 150 V and rated power of 36 W is built using GaN FETs. The converter prototype demonstrated a five fold reduction in the output impedance (which corresponds to conduction power loss) compared to a conventional Dickson converter, as a result of the split-phase controlled soft-charging operation.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Circulating Current Suppression of the Modular Multilevel Converter in a
           Double-Frequency Rotating Reference Frame
    • Authors: Bahrani; B.;Debnath, S.;Saeedifard, M.;
      Pages: 783 - 792
      Abstract: The modular multilevel converter (MMC) has attracted significant interest for medium-/high-power energy conversion applications due to its modularity, scalability, and excellent harmonic performance. One of the technical challenges associated with the operation of the MMC is the circulation of double-frequency harmonic currents within its phase legs. This paper proposes a circulating current control strategy in a double-frequency rotating reference frame, which, contrary to the existing solutions that are based on approximate/inaccurate models, relies on an experimentally identified nonparametric model of circulating currents to determine the coefficients of the controller. Minimizing the squared second norm of the error between the open-loop transfer function of the system and a desired one, the coefficients of the controller are determined. To guarantee the stability of the closed-loop system, the minimization problem is subjected to a few constraints. The validity and effectiveness of the proposed control strategy is confirmed, and its dynamic performance is compared with that of an existing solution by experimental results.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Monolithic High-Performance Buck Converter With Enhanced Current-Mode
           Control and Advanced Protection Circuits
    • Authors: Wang; L.;Zhao, M.;Wu, X.;
      Pages: 793 - 805
      Abstract: A monolithic high-performance step-down dc–dc converter for high power point-of-load application is presented in this paper. A novel adaptive quadratic slope compensation method and an adaptive antijittering ramp scheme are proposed to enhance the performance of widely used peak current-mode control. A fast overcurrent detection method together with a robust driver control logic design has been introduced to increase the circuits' reliability. The dc–dc converter has been designed and fabricated in a 0.35-μm Bipolar-CMOS-DMOS process with an area of 6 mm2. With the proposed enhanced current-mode control, our design allows more flexibility on inductor selection, switching frequency, and output voltage. Experimental results have shown great adaptability for various application configurations. This converter has also shown fast line step response and low PWM jittering. It can operate at beyond 9-A peak current and up to 1.4-MHz switching frequency with supply voltage from 2.35 to 6 V. Measured peak efficiency is 96.6% and over 92% efficiency for 6-A output current is realized as well.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • An FPGA-Based Advanced Control Strategy of a Grid­Tied PV CHB
    • Authors: Coppola; M.;Di Napoli, F.;Guerriero, P.;Iannuzzi, D.;Daliento, S.;Del Pizzo, A.;
      Pages: 806 - 816
      Abstract: In this paper, an advanced control strategy for grid­tied photovoltaic (PV) cascaded H­bridge (CHB) inverter is proposed. The circuit topology consists of a proper number of power cells (H­bridge configuration) connected in series and supplied by individual PV modules. The adopted control method is a mixed staircase­PWM technique performed by means of a sorting algorithm to determine cells' switching state. The cells' state is related to the need of charging or discharging a particular cell much more than the others by calculating the voltage error at each dc­link (e.g., by considering the difference between the maximum power point tracking (MPPT) reference and the measured quantity). A dedicated P&O MPPT permits to control independently the voltage of each dc­link; thus, increasing the power extraction even in mismatched conditions. In order to prove the effectiveness and feasibility of the proposed approach, a set of experiments are performed on a laboratory prototype of a single­phase five­level PV CHB. The control section is implemented on FPGA by using a dSPACE real­time hardware platform; thus, obtaining fully dedicated digital circuits. Experimental results show good performance in terms of MPPT efficiency, total harmonic distortion, and power factor in both normal operation and mismatch conditions.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Switching-Converter-Only Multiphase Envelope Modulator With Slew Rate
           Enhancer for LTE Power Amplifier Applications
    • Authors: Sankman; J.;Song, M.K.;Ma, D.;
      Pages: 817 - 826
      Abstract: With ever-growing energy crisis in wireless communication, effective envelope tracking solutions are in high demand for efficient operation of power amplifiers. Conventionally, a linear regulator is utilized to assist a switching converter to achieve fast tracking performance, but is highly inefficient. To overcome such an efficiency limitation, a dual-phase switching-converter-only topology is proposed in this paper. Synchronized adaptive voltage tracking control is introduced, which enables both clock synchronization and fast response for high-speed envelope tracking. To mitigate the inductor current slew rate limit of the switching converter, a push–pull slew rate enhancer (SRE) is designed. The SRE only operates when the switching converter reaches its inductor current slew rate limit, thereby maximizing the efficiency. The proposed envelope modulator is fabricated with a 0.18-μm CMOS process, achieving 85.8% peak efficiency at 1.5 W, tracking a 10-MHz LTE envelope.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Distributed Voltage Unbalance Compensation in Islanded Microgrids by Using
           a Dynamic Consensus Algorithm
    • Authors: Meng; L.;Zhao, X.;Tang, F.;Savaghebi, M.;Dragicevic, T.;Vasquez, J.C.;Guerrero, J.M.;
      Pages: 827 - 838
      Abstract: In islanded microgrids (MGs), distributed generators (DGs) can be employed as distributed compensators for improving the power quality in the consumer side. Two-level hierarchical control can be used for voltage unbalance compensation. Primary level, consisting of droop control and virtual impedance, can be applied to help the positive sequence active and reactive power sharing. Secondary level is used to assist voltage unbalance compensation. However, if distribution line differences are considered, the negative sequence current cannot be well shared among DGs. In order to overcome this problem, this paper proposes a distributed negative sequence current sharing method by using a dynamic consensus algorithm. In clear contrast with the previously proposed methods, this approach does not require a dedicated central controller, and the communication links are only required between neighboring DGs. The method is based on the modeling and analysis of the unbalanced system. Experimental results from an islanded MG system consisting of three 2.2-kVA inverters are shown to demonstrate the effectiveness of the method.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Virtual Space Vector Modulation Technique for the Reduction of
           Common-Mode Voltages in Both Magnitude and Third-Order Component
    • Authors: Tian; K.;Wang, J.;Wu, B.;Cheng, Z.;Zargari, N.R.;
      Pages: 839 - 848
      Abstract: A virtual space vector modulation technique reducing both magnitude and third-order harmonic component of the common-mode voltage (CMV) in a two-level voltage-source inverter (VSI) is proposed in this paper. The presented method employs a set of virtual space vectors constructed from original stationary space vectors to conduct modulation. Since the created virtual vectors have the lowest instantaneous and zero average CMVs, both the magnitude and third-order harmonic component of the generated CMV are reduced, contributing to better overall CMV performance and common-mode filter design in VSI applications. Three variants of the proposed modulation method using different virtual space vector combinations are presented. The concept of the virtual space vector modulation technique demonstrated with two-level inverter in this paper can also be extended to multilevel inverters. Simulation and experimental results, as well as comparisons with existing methods are provided to verify the proposed technique.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Dynamic Loss Minimization of Finite Control Set-Model Predictive Torque
           Control for Electric Drive System
    • Authors: Xie; W.;Wang, X.;Wang, F.;Xu, W.;Kennel, R.;Gerling, D.;
      Pages: 849 - 860
      Abstract: This paper proposes a dynamic optimization strategy of finite control set-model predictive torque control for permanent magnet synchronous machines, which takes into account the inverter losses and machine losses simultaneously. In order to reduce the switching losses (or to optimize the switching sequence) of the inverter, a recognized and feasible constrain which considers the accumulated ON/OFF times of the switches is implemented. The machine losses are taken into account by utilizing an optimal stator flux reference. An alternative loss model control method is proposed to calculate the optimal stator flux reference, which combines the conventional maximum torque/ampere method and the conventional loss model control method. Furthermore, a discrete-time machine model is introduced, which can reduce the predictive error at relative low switching frequency. The key results are illustrated by a combination of simulation and prototype interior permanent magnet machine drive measurements.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Hybrid Modulation Scheme for a High-Frequency AC-Link Inverter
    • Authors: Mazumder; S.K.;
      Pages: 861 - 870
      Abstract: This paper describes a hybrid modulation scheme for a high-frequency ac-link (HFACL) multistage inverter comprising a front-end dc/ac converter, followed by isolation transformers, an ac/pulsating-dc converter, and a pulsating-dc/ac converter. The hybrid modulation scheme enables 1) removal of the dc-link filter evident in conventional fixed dc-link (FDCL) inverters placed after the ac/pulsating-dc converter stage and before an end stage voltage source inverter and 2) significant reduction in switching loss of the inverter by reducing the high-frequency switching requirement of the pulsating-dc/ac converter by two-third yielding higher efficiency, improved voltage utilization, and reduced current stress. Unlike the FDCL approach, in the HFACL approach, hybrid modulation enables the retention of the sine-wave-modulated switching information at the output of the ac/pulsating-dc converter rather than filtering it to yield a fixed dc thereby reducing the high-frequency switching requirement for the pulsating-dc/ac converter. Overall, the following is outlined: 1) hybrid modulation scheme and its uniqueness, 2) operation of the HFACL inverter using the hybrid modulation scheme, 3) comparison of the efficiency and losses, current stress, and harmonic distortion between the hybrid-modulation-based HFACL inverter and the FDCL inverter, and 4) scaled experimental validation. It is noted that the term hybrid modulation has no similarity with the modulation scheme for a hybrid converter (which are conjugation of two types of converters based on a slow and fast device) reported in the literature. The term hybrid modulation scheme is simply chosen because at any given time only one leg of the inverter output stage (i.e., pulsating-dc/ac converter) switch under high frequency, while the other two legs do not switch. The outlined hybrid modulation scheme is unlike all reported discontinuous modulation schemes where the input is a dc and not a pulsating modulated dc, and at most o- ly one leg stays on or off permanently in a 60° or 120° cycle.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Reference Modification Model Digitally Controlled DC–DC Converter
           for Improvement of Transient Response
    • Authors: Kurokawa; F.;Yamanishi, A.;Hirotaki, S.;
      Pages: 871 - 883
      Abstract: This paper presents a reference modification model digitally controlled dc–dc converter. The proposed method is able to obtain superior transient response because it modifies a reference of conventional feedback loop against the change of output voltage. The modifying process operates only in the transient state. During the steady state, the feedforward control cancels a steady-state-error. Since the feedforward control uses the load current value, this paper discusses two current-sensing methods. One is the output current-sensing method using the sensing resistor, and the reactor current-sensing method using the R–C filter is discussed in order to reduce a performance loss by the sensing resistor. As a result, the output current-sensing method is effective in case that high-transient-response performance is required. On the other hand, it is better to use the reactor current-sensing method when efficiency is important.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • Line-Voltage Control Based on Wayside Energy Storage Systems for Tramway
    • Authors: Ciccarelli; F.;Iannuzzi, D.;Kondo, K.;Fratelli, L.;
      Pages: 884 - 899
      Abstract: This paper presents a control strategy for the power flow management of a wayside energy storage system based on a supercapacitor technology installed in a tramway network. The control is based on the management in real time of voltage levels at catenary point connections in order to optimize the energy flow among the running tramcars and substations with the goals of improving the energy saving and reducing the voltage drops in the supply network. The suggested control algorithm was experimentally validated using a laboratory-scale model to verify the effectiveness of the strategy. A lithium-ion capacitor module with 72 series-connected laminated cells of the JSR Micro ULTIMO type was used. Thus, an emulation of a real tramway network in the city of Naples (ANM) was implemented to evaluate the potential impact in terms of costs/benefits of the next installation on the ANM network.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
  • A Digital Predictive Peak Current Control for Power Factor Correction With
           Low-Input Current Distortion
    • Authors: Youn; H.;Park, J.;Park, K.;Baek, J.;Moon, G.;
      Pages: 900 - 912
      Abstract: A digital predictive peak current control (PPCC) employing the adaptive slope compensation is proposed in this paper. The PPCC precisely predicts the peak current reference with the adaptive slope compensation according to operation regions and load conditions. Thereby, the PPCC can control the peak inductor current, and it significantly reduces the total harmonic distortion compared to that of the conventional digital average current control with duty ratio feed-forward which is widely used. In addition, parts of the PPCC are implemented by utilizing the internal high-resolution ramp generator and comparator of a digital signal processor without external components. The principle and analysis of the PPCC are presented, and the performance and feasibility are verified by experimental results with universal input ( 90; {\rm V}_{\rm \rms} \sim 260; {\rm V}_{\rm \rms} ) and 750; {\rm W}-400; {\rm V} output laboratory prototype.
      PubDate: Jan. 2016
      Issue No: Vol. 31, No. 1 (2016)
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