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  Subjects -> ELECTRONICS (Total: 152 journals)
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 1)
Advances in Electronics     Open Access  
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: 71)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 11)
Annals of Telecommunications     Hybrid Journal   (Followers: 4)
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: 9)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 16)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 14)
Biomedical Instrumentation & Technology     Full-text available via subscription   (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: 9)
Consumer Electronics Times     Open Access   (Followers: 4)
Control Systems     Hybrid Journal   (Followers: 24)
Electronic Markets     Hybrid Journal   (Followers: 5)
Electronic Materials Letters     Hybrid Journal   (Followers: 3)
Electronics     Open Access   (Followers: 8)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 5)
Electronics Letters     Hybrid Journal   (Followers: 19)
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 22)
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: 8)
Facta Universitatis, Series : Electronics and Energetics     Open Access  
Foundations and TrendsĀ® in Communications and Information Theory     Full-text available via subscription   (Followers: 6)
Foundations and TrendsĀ® in Signal Processing     Full-text available via subscription   (Followers: 4)
Frequenz     Full-text available via subscription   (Followers: 2)
Frontiers of Optoelectronics     Hybrid Journal   (Followers: 2)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 21)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 15)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 14)
IEEE Consumer Electronics Magazine     Full-text available via subscription   (Followers: 17)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 12)
IEEE Journal of the Electron Devices Society     Open Access   (Followers: 2)
IEEE Power Electronics Magazine     Full-text available via subscription   (Followers: 6)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 10)
IEEE Transactions on Audio, Speech, and Language Processing     Hybrid Journal   (Followers: 12)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 25)
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: 7)
IET Power Electronics     Hybrid Journal   (Followers: 13)
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: 13)
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 5)
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: 11)
International Journal of Antennas and Propagation     Open Access   (Followers: 8)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 1)
International Journal of Biomedical Nanoscience and Nanotechnology     Hybrid Journal   (Followers: 7)
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: 5)
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Numerical Modelling:Electronic Networks, Devices and Fields     Hybrid Journal   (Followers: 2)
International Journal of Power Electronics     Hybrid Journal   (Followers: 7)
International Journal of Review in Electronics & Communication Engineering     Open Access   (Followers: 2)
International Journal of Sensors, Wireless Communications and Control     Hybrid Journal   (Followers: 2)
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: 8)
International Journal on Electrical and Power Engineering     Full-text available via subscription   (Followers: 11)
International Transaction of Electrical and Computer Engineers System     Open Access  
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 Electrical and Electronics Engineering Research     Open Access   (Followers: 2)
Journal of Electrical Bioimpedance     Full-text available via subscription   (Followers: 2)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 1)
Journal of Electromagnetic Analysis and Applications     Open Access   (Followers: 5)

        1 2 | Last

  IEEE Transactions on Power Electronics
  [SJR: 2.866]   [H-I: 128]   [23 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
    • Pages: C3 - C3
      Abstract: Provides a listing of current committee members and society officers.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Table of contents
    • Pages: C1 - C4
      Abstract: Presents the cover/table of contents for this issue of the periodical.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • IEEE Transactions on Power Electronics publication information
    • Pages: C2 - C2
      Abstract: Provides a listing of current staff, committee members and society officers.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Series-LC-Filtered Active Damper With Grid Disturbance
           Rejection for AC Power-Electronics-Based Power Systems
    • Authors: Wang; X.;Pang, Y.;Loh, P.C.;Blaabjerg, F.;
      Pages: 4037 - 4041
      Abstract: This letter proposes an active damper with a series LC filter for suppressing resonances in an ac power-electronics-based power system. The added series filter capacitor helps to withstand most of the system voltage, hence, allowing a lower rated converter to be used for implementing the active damper. Unlike an active power filter for mitigating low-frequency harmonics, the proposed damper dampens resonances at higher frequencies, whose values are dependent on interactions among multiple grid-connected converters and reactive elements of the system. Its control requirements are, therefore, different, particularly in the low-frequency range, where the series LC filter is predominantly capacitive, rather than the usual inductive characteristics that exist between voltage-source converters and the grid (or load). This low-frequency challenge can fortunately be resolved by the proposed fourth-order resonant controller, in addition to the second-order resonant controller used for resonance damping. Experimental results obtained have confirmed the effectiveness of these controllers, and hence, the feasibility of the active damper.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Energy Feed-Forward and Direct Feed-Forward Control for Solid-State
           Transformer
    • Authors: Ge; J.;Zhao, Z.;Yuan, L.;Lu, T.;
      Pages: 4042 - 4047
      Abstract: There is large voltage deviation on the dc bus of the three-stage solid-state transformer (SST) when the load suddenly changes. The feed-forward control can effectively reduce the voltage deviation and transition time. However, conventional power feed-forward scheme of SST cannot develop the feed-forward control to the full without extra current sensor. In this letter, an energy feed-forward scheme, which takes the energy changes of inductors into consideration, is proposed for the dual active bridge (DAB) controller. A direct feed-forward scheme, which directly passes the power of DAB converter to the rectifier stage, is proposed for the rectifier controller. They can further improve the dynamic performances of the two dc bus voltages, respectively. The experimental results in a 2-kW SST prototype are provided to verify the proposed feed-forward schemes and show the superior performances.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Rapid Switch Bridge Selection Method for Fully Integrated DCDC Buck
           Converters
    • Authors: Ostman; K.B.;Jarvenhaara, J.K.;
      Pages: 4048 - 4051
      Abstract: This letter presents a method for optimum selection of synchronous buck converter switch bridge topology and devices in the CMOS technology of choice. The comparative method targets maximum power efficiency, and it assumes an application where the dcdc converter is on the same IC as the load with a known constant operating point. As its principal idea, the method circumvents the need for exhaustive comparative simulation work to cover the vast design space of available MOS device and cascode/noncascode topology combinations. Instead, the method narrows the space by using a set of basic parameters to approximate the best combination. The result, thus, provides sharp focus for subsequent detailed design and topology-dependent optimization. The method is illustrated by comparing its results to simulations of synchronous 3.31.65-V buck converters in 45 and 65-nm CMOS with core, I/O, and high-voltage devices.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Seamless Transition Control for Modular Multilevel Converters When
           Inserting a Cold-Reserve Redundant Submodule
    • Authors: Li; B.;Zhang, Y.;Yang, R.;Xu, R.;Xu, D.;Wang, W.;
      Pages: 4052 - 4057
      Abstract: Redundant submodules (SMs) are always required to ensure the reliability of the modular multilevel converter (MMC). In this letter, a new control method for MMC is proposed to seamlessly ride through the period when bypassing a faulty SM and inserting a redundant SM. With the proposed method, the redundant SMs can be arranged in cold reserve mode so as to reduce the conduction losses, and when faced with SM failures, bypass of the faulty SM and insertion of the redundant SM will incur no inrush current problems. Besides, the capacitor of the newly inserted SM can get linearly charged. Validity of the proposed control method is verified experimentally based on a single-phase MMC prototype.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Nested Multilevel Topologies
    • Authors: Santos; E.C.d.;Muniz, J.H.G.;da Silva, E.R.C.;Jacobina, C.B.;
      Pages: 4058 - 4068
      Abstract: This paper proposes multilevel topologies based on the concept of nested arrangement. Such topologies are called nested multilevel converters, since the central point of the legs are connected at the same point, with the external legs involving the internal ones. Nested configurations present advantages as compared to the equivalent NPC topologies in terms of reduced number of diodes and consequently higher efficiency. In addition to proposing a new family of power electronics converters, this paper presents an optimized pulse width modulation strategy that allows synthesizing voltage waveforms with higher quality, a losses comparison with the NPC topology, and a general comparison with other topologies proposed in the technical literature. Simulated and experimental results are presented to validate the theoretical expectations.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Novel and Simple Single-Phase Modulator for the Nested Neutral-Point
           Clamped (NNPC) Converter
    • Authors: Narimani; M.;Wu, B.;Cheng, Z.;Zargari, N.R.;
      Pages: 4069 - 4078
      Abstract: The nested neutral-point clamped (NNPC) converter is a four-level converter topology for medium-voltage applications with interesting properties such as operating over a wide range of voltages (2.4–7.2 KV) without the need for connecting the power semiconductor in series, high quality output voltage, and less number of components in compare to other classical four-level topologies. The control and balance of the flying capacitors (FCs) of the NNPC converter can be done by different control techniques taking advantage of the large number of redundant switching states. This paper presents a simple single-phase modulator for the NNPC converter, which can be applied to each phase of a three-phase NNPC converter. The proposed simple technique can control and balance the FCs to their desired values. Performance of the proposed technique under different operating conditions is investigated in the MATLAB/Simulink environment. The feasibility of the proposed converter is evaluated experimentally.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Characterization and Implementation of Dual-SiC MOSFET Modules for Future
           Use in Traction Converters
    • Authors: Fabre; J.;Ladoux, P.;Piton, M.;
      Pages: 4079 - 4090
      Abstract: Silicon (Si) insulated-gate bipolar transistors are widely used in railway traction converters. In the near future, silicon carbide (SiC) technology will push the limits of switching devices in three directions: higher blocking voltage, higher operating temperature, and higher switching speeds. The first silicon carbide (SiC) MOSFET modules are available on the market and look promising. Although they are still limited in breakdown voltage, these wide-bandgap components should improve traction-chain efficiency. Particularly, a significant reduction in the switching losses is expected which should lead to improvements in power–weight ratios. Nevertheless, because of the high switching speed and the high current levels required by traction applications, the implementation of these new modules is critical. An original method is proposed to compare, in terms of stray inductance, several dc bus-bar designs. To evaluate the potential of these new devices, a first set of measurements, based on a single-pulse test-bench, was obtained. The switching behavior of SiC devices was well understood at turn-off and turn-on. To complete this work, the authors use an opposition method to compare Si-IGBT and SiC-MOSFET modules in voltage source inverter operation. For this purpose, a second test-bench, allowing electrical and thermal measurements, was developed. Experimental results confirm the theoretical loss-calculation of the single-pulse tests and the correct operation of up to three modules directly connected in parallel. This analysis provides guidelines for a full SiC inverter design, and prospects for developments in traction applications are presented.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Review of Multilevel Selective Harmonic Elimination PWM: Formulations,
           Solving Algorithms, Implementation and Applications
    • Authors: Dahidah; M.S.A.;Konstantinou, G.;Agelidis, V.G.;
      Pages: 4091 - 4106
      Abstract: Selective harmonic elimination pulse width modulation (SHE-PWM) offers tight control of the harmonic spectrum of a given voltage and/or current waveform generated by a power electronics converter. Owing to its formulation and focus on elimination of low-order harmonics, it is highly beneficial for high-power converters operating with low switching frequencies. Over the last decade, the application of SHE-PWM has been extended to include multilevel converters. This paper provides a comprehensive review of the SHE-PWM modulation technique, aimed at its application to multilevel converters. This review focuses on various aspects of multilevel SHE-PWM, including different problem formulations, solving algorithms, and implementation in various multilevel converter topologies. An overview of current and future applications of multilevel SHE-PWM is also provided.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • An Adaptive ZVS Full-Bridge DC–DC Converter With Reduced Conduction
           Losses and Frequency Variation Range
    • Authors: Safaee; A.;Jain, P.K.;Bakhshai, A.;
      Pages: 4107 - 4118
      Abstract: This paper presents a description and analysis of a full-bridge converter with a novel passive and robust auxiliary circuit for zero-voltage-switching (ZVS) operation. A generalized time-domain state-space analysis is provided to describe the steady-state behavior of the auxiliary circuit. Complete comparison between the well-known single-inductor auxiliary circuit, and the proposed one is presented. For a similar peak current in the auxiliary branch, needed for ZVS, a minimum of 20% reduction in rms current is achieved to decrease the conduction losses in the power switches and in the auxiliary circuit. Also, 65% reduction in switching frequency variation is obtained. This narrower frequency range reduces the need for very high-frequency operation and the associated gate driver losses as well as the difficulty of electromagnetic interference (EMI) filter design. All the theoretical results are experimentally verified.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Modified Voltage Balancing Algorithm for the Modular Multilevel
           Converter: Evaluation for Staircase and Phase-Disposition PWM
    • Authors: Darus; R.;Pou, J.;Konstantinou, G.;Ceballos, S.;Picas, R.;Agelidis, V.G.;
      Pages: 4119 - 4127
      Abstract: This paper introduces a low complexity implementation of the voltage balancing algorithm aiming to reduce the switching frequency of the power devices in modular multilevel converters (MMCs). The proposed algorithm features a relatively simple implementation without any conditional execution requirements and is easily expandable regardless of the number of submodules (SMs). Two modulation techniques are evaluated, namely the staircase modulation and the phase-disposition pulse width modulation (PD-PWM) under the conventional and the proposed algorithm. Using a circulating current controller in an MMC with 12 SMs per arm, PD-PWM yields better results compared to the staircase modulation technique. The test condition for this comparison is such that the power devices operate at a similar switching frequency and produce similar amplitudes to the capacitor voltage ripples in both modulation techniques. The results are verified through extensive simulations and experiments on a low power phase-leg MMC laboratory prototype.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Analytical Model of the Half-Bridge Series Resonant Inverter for Improved
           Power Conversion Efficiency and Performance
    • Authors: Sarnago; H.;Lucia, O.;Mediano, A.;Burdio, J.M.;
      Pages: 4128 - 4143
      Abstract: Resonant power conversion is a key enabling technology of dc–dc conversion, inverters and contactless energy transfer systems. This paper presents an analytical model of the series resonant half-bridge topology aimed at improving the design, control, and efficiency of resonant power converters. The main contribution is a closed-form expression of the main converter waveforms as well as output power and efficiency. This model enables a fast design-space exploration, as well as the implementation of advanced control techniques using adaptive control or real-time emulation, significantly improving the converter operation. The analytical expressions presented have been applied and verified through a half-bridge series resonant inverter applied to induction heating applications, proving the accuracy and effectiveness of the proposed model.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Optimal Design of DCM LCC Resonant Converter With
           Inductive Filter Based on Mode Boundary Map
    • Authors: Tan; X.;Ruan, X.;
      Pages: 4144 - 4155
      Abstract: LCC resonant converter with inductive filter operating in discontinuous current mode (DCM) can achieve zero-current switching (ZCS) for both the power switches and rectifier diodes. Therefore, it is suitable for high-power, low-voltage, high-current power supplies. The DCM LCC resonant converter with inductive filter might operate in different operating modes when input voltage or load changes, which challenges the design. This paper derives a mode boundary map, from which the operating mode of the converter can be easily determined. Based on the mode boundary map, a generalized optimal design procedure is proposed and a set of optimal and normalized converter parameters is determined, which can be easily converted into real parameters according to the converter specification. Three 5 kW prototypes with different converter parameters are fabricated and tested in the lab, and the experimental results show that with the set of optimal parameters, the converter can achieve the highest efficiency over the entire input voltage and load range.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Hybrid-Type Full-Bridge DC/DC Converter With High Efficiency
    • Authors: Lee; S.;Park, C.;Kwon, J.;Kwon, B.;
      Pages: 4156 - 4164
      Abstract: This paper presents a hybrid-type full-bridge dc/dc converter with high efficiency. Using a hybrid control scheme with a simple circuit structure, the proposed dc/dc converter has a hybrid operation mode. Under a normal input range, the proposed converter operates as a phase-shift full-bridge series-resonant converter that provides high efficiency by applying soft switching on all switches and rectifier diodes and reducing conduction losses. When the input is lower than the normal input range, the converter operates as an active-clamp step-up converter that enhances an operation range. Due to the hybrid operation, the proposed converter operates with larger phase-shift value than the conventional converters under the normal input range. Thus, the proposed converter is capable of being designed to give high power conversion efficiency and its operation range is extended. A 1-kW prototype is implemented to confirm the theoretical analysis and validity of the proposed converter.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Series-Connected HV-IGBTs Using Active Voltage Balancing Control With
           Status Feedback Circuit
    • Authors: Ji; S.;Lu, T.;Zhao, Z.;Yu, H.;Yuan, L.;
      Pages: 4165 - 4174
      Abstract: Transient voltage unbalance is the major problem that limits the application of series-connected IGBTs in high-voltage and high-power converters. Asynchronous gate delay causes series-connected IGBTs not to turn-on and turn-off at the same time resulting in severely unbalanced voltage sharing. An active voltage balancing control technique is proposed in this paper to solve the asynchronous gate delay problem. By sampling the feedback signal caused by unbalanced voltage sharing, the microcontroller generates a time delay for the gate driver to compensate the asynchronous gate delay. The most vital part of active voltage balancing control, the status feedback circuit, is also discussed in detail in this paper. The function of the status feedback circuit and the effect of active voltage balancing control are verified in a two series-connected HV-IGBTs platform in rated operation (5 kV bus voltage and 600 A load current).
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Front-End Converter With Integrated PFC and DC–DC Functions for a
           Fuel Cell UPS With DSP-Based Control
    • Authors: Maciel; R.S.;de Freitas, L.C.;Coelho, E.A.A.;Vieira, J.B.;de Freitas, L.C.G.;
      Pages: 4175 - 4188
      Abstract: This paper presents the development of a boost converter with integrated power factor correction (PFC) and dc–dc functions for a proton exchange membrane fuel cell (PEMFC) uninterruptable power supply (UPS). Through the use of a passive resonant soft-commutation cell, which besides providing improvements in efficiency and reduced electromagnetic interference, produces a naturally controlled supercapacitor charger circuit. Supercapacitors are employed in order to provide a proper startup of the PEMFC and to improve its dynamic response. The control strategy is implemented using a digital signal processor and is based on the average current control method for sinusoidal input current imposition ensuring, therefore, a high input power factor and low harmonic distortion of current. The main features of the proposed solution are the use of a PEMFC as an energy storage system, which replace the battery banks commonly used in UPS systems, eliminating the common drawbacks related to working life and maintenance issues, and the use of a front-end converter with integrated PFC and dc–dc functions eliminating the necessity of using an additional and dedicated dc–dc converter for the PEMFC. During power failure or even in conditions of severe voltage sags on the ac mains, the PEMFC is activated assuring the continuous power supply to the electronic load connected to the dc link. In this paper, the authors present the full study description including experimental results that corroborate with the theory herein presented.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Family of High-Voltage Gain Single-Phase Hybrid Switched-Capacitor PFC
           Rectifiers
    • Authors: Cortez; D.F.;Barbi, I.;
      Pages: 4189 - 4198
      Abstract: This paper presents the derivation, the analysis, and the experimentation of a family of unidirectional three-level PFC rectifiers, based on pulse-width-modulated hybrid switched capacitor principle. The topologies feature reduced voltage stress across the switches, low number of switches, control of the output voltage, and high-voltage gain without the utilization of transformers. Experimental results for a laboratory prototype of 220 {\bf V}_{{\bf \rms}} to 1600 {\bf V}_{{\bf dc}} voltages and nominal power of 2500 W are included in the paper, to validate the theoretical analysis, where the measured maximum efficiency reached 97.91%. The proposed converters are suitable for applications that require rectification with unity power factor and high-voltage gain.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Predicting the Impact of Magnetic Components Used for EMI Suppression on
           the Base-Band of a Power Amplifier
    • Authors: Mrad; R.;Pillonnet, G.;Morel, F.;Vollaire, C.;Nagari, A.;
      Pages: 4199 - 4208
      Abstract: Class-D audio amplifiers are switching circuits that produce serious Electromagnetic (EM) emissions and disturb the surrounding electronics. In order to reduce these emissions, electromagnetic compatibility (EMC) filters with ferrite beads are used. However, ferrite beads contain magnetic materials that have a nonlinear behavior. Thus, they have an unfavorable impact on the system audio quality. The common ferrite bead models do not take into account nonlinear phenomena. Thus, to predict the impact on the signal quality, this paper models the ferrite bead using the Jiles–Atherton magnetic material theory. The presented model provides the designers with a tool to quantify the effect of EMC filters on the total harmonic distortion (THD) of audio amplifiers. The simulated and measured results show that the tested ferrite bead have a negative effect on the audio signal for a wide range of amplitudes and can increase the THD up to 37 dB. Finally, this paper highlights the impact of the magnetic material type on the audio distortion by simulating the same component with different types of materials.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Efficient Maximum Power Point Tracking for a Distributed PV System under
           Rapidly Changing Environmental Conditions
    • Authors: Hong; Y.;Pham, S.N.;Yoo, T.;Chae, K.;Baek, K.;Kim, Y.S.;
      Pages: 4209 - 4218
      Abstract: When conventional maximum power point tracking (MPPT) techniques are required to operate fast under rapidly changing environmental conditions, a large power loss can be caused by slow tracking speed, output power fluctuation, or additionally required ad hoc parameters. This paper proposes a fast and efficient MPPT technique that minimizes the power loss with the adaptively binary-weighted step (ABWS) followed by the monotonically decreased step (MDS) without causing output power fluctuation or requiring additional ad hoc parameter. The proposed MPPT system for a photovoltaic (PV) module is implemented by a boost converter with a microcontroller unit. The theoretical analysis and the simulation results show that the proposed MPPT provides fast and accurate tracking under rapidly changing environmental conditions. The experimental results based on a distributed PV system demonstrate that the proposed MPPT technique is superior to the conventional perturb and observe (P&O) technique, which reduces the tracking time and the overall power loss by up to 82.95%, 91.51% and 82.46%, 97.71% for two PV modules, respectively.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Multiobjective Optimization and Topology Selection for a Module-Integrated
           Inverter
    • Authors: Mirjafari; M.;Harb, S.;Balog, R.S.;
      Pages: 4219 - 4231
      Abstract: As photovoltaic energy continues to gain market penetration, thanks in part to substantial cost reductions on the solar modules, attention is shifting to the balance-of-system performance and costs. This paper proposes an approach to explore the design limits of a module-integrated inverter by means of the component-level multiobjective optimization. A two-stage inverter along with an active filter to eliminate double-frequency content of the dc-link current is proposed for the topology of module-integrated inverter, and three candidate topologies were taken into account for the dc–dc stage. Efficiency, volume, and reliability of the converters are taken as objective functions, and comprehensive component modeling is performed. Pareto frontiers reveal that the limits of the system are illustrated, which help the designer to pick the most suitable topology and design for the entire converter. Experimental results show the validity of the modeling and optimization technique.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Electrochemical State-Based Sinusoidal Ripple Current Charging Control
    • Authors: Lee; Y.;Park, S.;
      Pages: 4232 - 4243
      Abstract: This paper presents a sinusoidal ripple current charging algorithm based on embedded impedance measurements. Existing battery charging strategies typically do not take into account the electrochemical properties of batteries, because these factors are difficult to obtain during charging operation. Factors of concern include lithium plating, growth of a solid electrolyte interphase, limited exchange current, and slow diffusion rates. It is beneficial to utilize these parameters during charging operation, because the charging current can adapt to the time-varying characteristics of a battery. Consequently, battery life cycle, charging speed, and charging efficiency all improve. In this paper, rigorous analysis of electrochemical characteristics is performed and a method for minimization of variations of charge transfer impedance is explained based on a sinusoidal ripple current charging algorithm. To obtain the optimal ripple current frequency, ac impedance analysis based on the dq transformation method is proposed. As a result, this method improved charging efficiency and reduced lithium plating by activation polarization. Simulation and experimental results using a 14.6-V LiFeMgPO4 battery are used to validate and demonstrate the performance of the proposed control scheme. Based on the proposed control scheme, the charging time and efficiency of the Li-ion battery are improved by 5.1% and 5.6%, respectively.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Torque Ripple Reduction in a DFIG-DC System by Resonant Current
           Controllers
    • Authors: Iacchetti; M.F.;Marques, G.D.;Perini, R.;
      Pages: 4244 - 4254
      Abstract: A DFIG connected to a dc bus by a diode rectifier and a unique reduced-power PWM converter is considered in this paper. With respect to the traditional ac-grid connected DFIG, such a layout avoids the grid-side PWM converter and is an interesting solution to integrate the DFIG in a dc microgrid together with other generating units, loads as well as storages. The peculiarity of the DFIG, which allows the control of the rotor current space vector independently of the mechanical position, offers two important benefits when the stator is connected to a constant voltage dc grid by a diode bridge: it avoids the need to boost the flux amplitude at low speed, and it allows to considerably reduce the torque ripple due to the diode commutation. This last issue is developed in this paper by using a field-oriented control scheme based on proportional-integral and resonant Controllers. The proposed control is validated through simulation and experiments.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Novel High Step-up DC/DC Converter Based on Integrating Coupled Inductor
           and Switched-Capacitor Techniques for Renewable Energy Applications
    • Authors: Ajami; A.;Ardi, H.;Farakhor, A.;
      Pages: 4255 - 4263
      Abstract: In this paper, a novel high step-up dc/dc converter is presented for renewable energy applications. The suggested structure consists of a coupled inductor and two voltage multiplier cells, in order to obtain high step-up voltage gain. In addition, two capacitors are charged during the switch-off period, using the energy stored in the coupled inductor which increases the voltage transfer gain. The energy stored in the leakage inductance is recycled with the use of a passive clamp circuit. The voltage stress on the main power switch is also reduced in the proposed topology. Therefore, a main power switch with low resistance R_{{\rm DS} ({\rm ON})} can be used to reduce the conduction losses. The operation principle and the steady-state analyses are discussed thoroughly. To verify the performance of the presented converter, a 300-W laboratory prototype circuit is implemented. The results validate the theoretical analyses and the practicability of the presented high step-up converter.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • New Interleaved Current-Fed Resonant Converter With Significantly Reduced
           High Current Side Output Filter for EV and HEV Applications
    • Authors: Moon; D.;Park, J.;Choi, S.;
      Pages: 4264 - 4271
      Abstract: This paper proposes a new interleaved current-fed resonant converter with significantly reduced high current side output filter. The proposed interleaved converter has theoretically zero output filter capacitance, low-input current ripple, ZCS turn-on and turn-off for all switches and diodes, and zero di/dt at turn-off of diodes when operated at load independent points. A two-stage power conversion technique is applied to the interleaved converter for high efficiency under wide voltage range operation. A 2-kW prototype of the proposed low-voltage dc/dc converter for EV and HEV applications is built and tested to verify the validity of the proposed operation.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Bridgeless PFC-Modified SEPIC Rectifier With Extended Gain for Universal
           Input Voltage Applications
    • Authors: Al Gabri; A.M.;Fardoun, A.A.;Ismail, E.H.;
      Pages: 4272 - 4282
      Abstract: In this paper, a new single-phase ac–dc PFC bridgeless rectifier with multiplier stage to improve the efficiency at low input voltage and reduce the switch-voltage stress is introduced. The absence of an input rectifier bridge in the proposed rectifier and the presence of only two semiconductor switches in the current flowing path during each switching cycle result in less conduction losses and improved thermal management compared to the conventional full bridge topology. Lower switch voltage stress allows utilizing a MOSFET with lower R_{\rm{DS-on}} . The proposed topology is designed to operate in discontinuous conduction mode (DCM) to achieve almost a unity power factor and low total harmonic distortion (THD) of the input current. The DCM operation gives additional advantages such as zero-current turn-on in the power switches and simple control circuitry. The proposed topology is compared with modified full-bridge SEPIC rectifier in terms of efficiency, THD, and power factor. Detailed converter analysis, small signal model, and closed-loop analysis are presented. Experimental results for a 200 W/400 V_{{\rm dc}} at universal line voltage range to evaluate the performance of the proposed bridgeless PFC rectifiers are detailed.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Portable Ultracapacitor-Based Power Source for Emergency Starting of
           Internal Combustion Engines
    • Authors: Averbukh; M.;Lineykin, S.;Kuperman, A.;
      Pages: 4283 - 4290
      Abstract: An original ultracapacitor (UC) based compact electric power source is introduced in the paper. The device employs the synergy between rich energy content of vehicle lead-acid batteries and power capabilities of UCs to allow emergency starting of internal combustion engine in case of a weak battery. The UC-based power source is capable of charging at low rate from the battery and then providing current burst required for proper engine starting. A prototype is designed employing original power circuitry, and a dedicated algorithm for optimal UC charging is developed. The device is successfully used for diesel engine starting, as shown by experimental results.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • 13.56 MHz High Density DC–DC Converter With PCB Inductors
    • Authors: Liang; W.;Glaser, J.;Rivas, J.;
      Pages: 4291 - 4301
      Abstract: This paper presents the design and implementation of a high density 150–200 V to 28 V, 200–400 W resonant dc–dc converter with embedded inductors. The converter has a switching frequency of 13.56 MHz and uses air-core toroidal inductors fabricated with printed circuit board (PCB) technology. Implementing toroidal inductors with the PCB reduces inductance variation. Hence, the tuning and implementation of the converter are simplified while achieving high levels of performance and power density. By not using magnetic cores, the inductors also maintain stable values over a wide temperature range. Moreover, the paper discusses the tradeoffs between simplicity and performance of implementing a hard-switched gate drive at megahertz switching frequencies. We describe the advantages of resonant power converter topologies in applications requiring high density and high performance in demanding environmental conditions.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Analysis Model for Magnetic Energy Harvesters
    • Authors: Moon; J.;Leeb, S.B.;
      Pages: 4302 - 4311
      Abstract: Energy harvesting offers an important design option for creating sensing and control elements without a requirement for custom wiring or batteries. An exciting possibility creates a “self-powered” sensor node with an integrated energy harvester that can extract power from the magnetic fields around a power line to a load, in the manner of a current transformer. However, this “current transformer” provides not just current sensing, but also power for a sensor package, all without ohmic contact. This paper provides a technique for design optimization for maximizing power harvest, revealing a critical result: For any given core in any particular application, power harvest is maximized when the core is permitted to saturate at an opportune time in the line cycle. Circuits for optimizing this power transfer window and experimental results supporting the analysis are presented in this paper.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Interleaved Boost-Integrated LLC Resonant Converter With
           Fixed-Frequency PWM Control for Renewable Energy Generation Applications
    • Authors: Sun; X.;Shen, Y.;Zhu, Y.;Guo, X.;
      Pages: 4312 - 4326
      Abstract: This paper proposes a current-fed LLC resonant converter that is able to achieve high efficiency over a wide input voltage range. It is derived by integrating a two-phase interleaved boost circuit and a full-bridge LLC circuit together by virtue of sharing the same full-bridge switching unit. Compared with conventional full-bridge LLC converter, the gain characteristic is improved in terms of both gain range and optimal operation area, fixed-frequency pulsewidth-modulated (PWM) control is employed to achieve output voltage regulation, and the input current ripple is minimized as well. The voltage across the turned-off primary-side switch can be always clamped by the bus voltage, reducing the switch voltage stress. Besides, its other distinct features, such as single-stage configuration, and soft switching for all switches also contribute to high power conversion efficiency. The operation principles are presented, and then the main characteristics regarding gain, input current ripple, and zero-voltage switching (ZVS) considering the nonlinear output capacitance of MOSFET are investigated and compared with conventional solutions. Also, the design procedure for some key parameters is presented, and two kinds of interleaved boost integrated resonant converter topologies are generalized. Finally, experimental results of a converter prototype with 120–240 V input and 24 V/25 A output verify all considerations.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Novel Primary-Side Controlled Universal-Input AC–DC LED Driver
           Based on a Source-Driving Control Scheme
    • Authors: Chen; Y.;Chang, C.;Yang, P.;
      Pages: 4327 - 4335
      Abstract: A novel primary-side controlled universal-input ac–dc LED driver based on the source-driving control scheme is proposed in this paper, which employs low-voltage control mosfet M_{2} to drive high-voltage power mosfet M_{1} without an auxiliary winding commonly used in the conventional primary-side controlled scheme. The proposed control IC adopts minimum voltage detection circuit to monitor the zero crossing information of secondary winding current. The demagnetization time signal is generated by demagnetization time detection circuit. In addition, the ratio between the secondary winding demagnetization time T_{{\rm Demag}} and switching period T_{S} is maintained constant by adopting the intelligent charging and discharging circuit, finally achieving high-precision constant output current. A control IC for the proposed LED driver has been fabricated in TSMC 0.35 μm 5 V/600 V CMOS/LDMOS process. Experimental results of a 3-W circuit prototype show that the constant current precision is within ±1% in a wide range of universal-input ac voltage from 85 to 264 V, and that above 80% efficiency is obtained when driving three 1-W LEDs. The start-up time is only 46 ms under 90 Vac and 60 Hz-input, and the standby power is tested to be lower than 142 mW under 220 Vac and 50 Hz-input.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Direct AC/DC Rectifier With Mitigated Low-Frequency Ripple Through
           Inductor-Current Waveform Control
    • Authors: Li; S.;Zhu, G.;Tan, S.;Hui, S.Y.R.;
      Pages: 4336 - 4348
      Abstract: In a rectification system with unity power factor, the input power consists of a dc and a double-line frequency power component. Traditionally, an electrolytic capacitor (E-Cap) is used to buffer the double-line frequency power such that the dc output presents a small voltage ripple. The use of E-Cap significantly limits the lifetime of the rectifier system. In this paper, a differential ac/dc rectifier based on the use of an inductor-current waveform control methodology is proposed such that a single-stage direct ac/dc rectification without the need of an E-Cap for buffering the double-line frequency power, and a front-stage diode rectifier circuit can be achieved. The feasibility of the proposal has been practically confirmed in an experimental prototype.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • High-Power-Factor Rectifier Using the Modified SEPIC Converter Operating
           in Discontinuous Conduction Mode
    • Authors: Bianchin; C.G.;Gules, R.;Badin, A.A.;Ribeiro Romaneli, E.F.;
      Pages: 4349 - 4364
      Abstract: The theoretical and experimental analysis of a modified version of the SEPIC dc–dc converter used as preregulator operating in discontinuous conduction mode (DCM) is presented in this paper. The proposed converter presents a low input current ripple operating in DCM, and the switch voltage is lower than the output voltage. The switch voltage reduction increases the converter reliability and a low drain-to-source on-resistance ( {\rm RDS}_{{\rm on}} ) MOSFET can be used depending on the converter specification. Moreover, a digital control technique is applied to the proposed converter in order to reduce the third-harmonic input current distortion resultant of the operation in DCM. Finally, a 100-W prototype was developed operating with efficiency equal to 95.6%.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Universal High-Frequency Three-Phase Electric-Motor Model Suitable for
           the Delta- and Star-Winding Connections
    • Authors: Vidmar; G.;Miljavec, D.;
      Pages: 4365 - 4376
      Abstract: A universal high-frequency three-phase electric-motor model to be used in the design process of the electric-motor drive systems is proposed. The model can be combined with the models of the filter, cable, and inverter to form a complete drive system. It allows for a common and differential-mode high-frequency analysis in studying the bearing currents, electromagnetic interference, and overvoltages in the motor windings caused by the high-frequency reflections. The model phase is symmetrical meaning that the beginning and end of each phase are equal and the central part is inserted between them. This enables modeling of both the delta and star-winding connections of the three phases. The equations used to calculate the model parameters are presented. They are based on the common and differential-mode impedance measurements. The model can be simplified when considering only electric-discharge machining bearing currents, as they are affected only by the common-mode states. A simplified model to be used in the delta-winding connection is also presented. The model-calculated common and differential-mode impedances are compared with the impedances measured on a 6.5-kW outer-rotor brushless direct-current motor. This paper ends by providing the obtained simulation and measurement results for the common and differential-mode currents and bearing voltages of the studied three-phase delta-winding-connected electric motor.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Matrix Converter Ride-Through Configuration Using Input Filter
           Capacitors as an Energy Exchange Mechanism
    • Authors: Orser; D.;Mohan, N.;
      Pages: 4377 - 4385
      Abstract: A novel ride-through approach for matrix converters in adjustable speed drives is presented. The input capacitors are utilized to transfer energy from the spinning inertia of the motor to support the motor flux during grid fault events. The addition of three bidirection switches is required to isolate the input filter capacitors from the collapsed grid voltages. The addition of input switches, a ride-through vector control strategy, and post fault reconnection logic are shown to enable ride-through of many cycle faults without the use of an additional energy storage device. In this paper, the control and reconnect strategies are discussed followed by simulations of the system and the presentation of experimental results. Through a short review of power quality assessments, it is shown that these improvements allow matrix converter-based adjustable speed drives to operate in a majority of real world fault situations.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • New Optimal Pulsewidth Modulation for Single DC-Link Dual-Inverter Fed
           Open-End Stator Winding Induction Motor Drive
    • Authors: Edpuganti; A.;Rathore, A.K.;
      Pages: 4386 - 4393
      Abstract: The multilevel topology with dual inverters feeding both ends of an open-end stator winding of an induction motor has been introduced around two decades ago. A common-mode inductor is usually required in series with motor windings to suppress zero-sequence or common-mode currents. In case of medium voltage high-power drives, low device switching frequency operation is preferred to improve the overall system efficiency. However, it increases the harmonic distortion of machine stator currents. Therefore, the goal of our study is to propose new optimal pulse  width modulation to achieve: low device switching frequency, minimal harmonic distortion of machine stator currents, and elimination of zero-sequence currents. The main idea is to select the switching angles of two inverters such that zero-sequence components are eliminated and, then, perform optimization to determine switching angles that minimize the harmonic distortion of machine stator currents. The experimental results obtained from dual two-level and dual three-level inverter fed 1.5-kW open-end stator winding IM drive demonstrated the effectiveness of a proposed modulation technique.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Sensorless Control of PMSM for the Whole Speed Range Using
           Two-Degree-of-Freedom Current Control and HF Test Current Injection for
           Low-Speed Range
    • Authors: Seilmeier; M.;Piepenbreier, B.;
      Pages: 4394 - 4403
      Abstract: In this paper, an innovative sensorless two-degree-of-freedom current control scheme for the whole speed range is proposed. It consists of a model-based dynamic feedforward control to set the reference response and model reference tracking controllers providing disturbance rejection and the position error signals needed for sensorless control. For low- and zero-speed operation, alternating test current injection is used to gain a position error signal. A flatness-based test signal precontrol provides compensation for secondary saliencies like cross-saturation and higher harmonics. For mid- and high-speed operation, it is shown how the model-based dynamic feedforward control can be modified to obtain a high-quality position error signal from the tracking controller. No additional model-based estimator evaluating back-EMF information is needed. The effectiveness of the proposed method is proven by experimental results.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Effect of Nonlinearity of Parasitic Capacitance on Analysis and Design of
           Class E/F3 Power Amplifier
    • Authors: Hayati; M.;Sheikhi, A.;Grebennikov, A.;
      Pages: 4404 - 4411
      Abstract: In this paper, the analysis and comparison of a Class-E/F3 power amplifier with nonlinear and linear shunt capacitance at 50% duty ratio are presented. An analytical analysis for nonlinear and linear shunt capacitance is presented, and its effects on the performance of the power amplifier are discussed. The different parameters, such as series reactance, peak switch voltage, and power output capability are compared for power amplifiers with linear and nonlinear shunt capacitance. Two design examples of the Class-E/F3 power amplifiers with IRF530 mosfets and lumped elements at an operating frequency of 4 MHz are analyzed. The PSpice simulation and measurement for the power amplifier with nonlinear shunt capacitance have been done. The results agree with the analytical expressions that show the validity of the analytical expressions derived at zero-voltage switching and zero derivative voltage switching conditions.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • An Extended Flux Model-Based Rotor Position Estimator for Sensorless
           Control of Salient-Pole Permanent-Magnet Synchronous Machines
    • Authors: Zhao; Y.;Zhang, Z.;Qiao, W.;Wu, L.;
      Pages: 4412 - 4422
      Abstract: Starting from the classical dynamic model of salient-pole permanent-magnet synchronous machines (PMSMs) expressed in the stationary reference frame, this paper presents a mathematical model reconstruction process for salient-pole PMSMs, from which an extended flux-based machine model is derived. Compared with the commonly used extended electromotive force-based model, the extended flux-based model has notable advantages of simpler model structure and less sensitive to the variations of machine parameters and operating conditions. A new extended flux model-based rotor position estimator is then proposed for sensorless control of salient-pole PMSMs by utilizing a sliding-mode observer with a dynamic position compensator. The latter improves the dynamic performance and low-speed operating capability of the sensorless control system. Both simulation and experimental results are provided to validate the proposed rotor position estimator and the sensorless control system for salient-pole PMSMs.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • An Online Modulation Strategy to Control the Matrix Converter Under
           Unbalanced Input Conditions
    • Authors: Dasika; J.D.;Saeedifard, M.;
      Pages: 4423 - 4436
      Abstract: Due to absence of a dc-link energy storage element in the direct matrix converter (MC), any abnormality/disturbance in the input voltages is directly reflected on the output voltages. In this paper, a new modulation strategy to control the 3 $times$ 3 MC under unbalanced input voltage conditions is proposed. The proposed strategy is based on modification of the space vector modulation strategy, which formulates and solves an optimization problem to determine the best switching states and their corresponding optimal duty cycles, such that the errors in the output voltages and the input currents under unbalanced input voltage conditions are minimized. The salient feature of the proposed strategy is its capability to extend the output operating range of the MC. The proposed strategy ensures that optimal performance of the MC over the entire operating range, including the case when the converter operates with an output voltage greater than the maximum attainable balanced output voltage under unbalanced input voltage conditions, is achieved. Performance of the proposed strategy is evaluated and validated based on time-domain simulation studies in the MATLAB/Simulink software environment and experimentation on a scaled-down laboratory prototype.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Contour-Mode Ring-Shaped AlN Microresonator on Si and Feasibility of Its
           Application in Series-Resonant Converter
    • Authors: Imtiaz; A.M.;Khan, F.H.;Walling, J.S.;
      Pages: 4437 - 4454
      Abstract: Microelectromechanical systems (MEMS) resonators on Si have the potential to replace the discrete passive components in a power converter. The main intention of this paper is to present a ring-shaped aluminum nitride (AlN) piezoelectric microresonator that can be used as an energy-transferring device to replace inductors/capacitors in low-power resonant converters for biomedical applications. Finite-element simulation results have been provided, showing the mode of vibration at resonant frequency. The zero-voltage switching (ZVS) condition for a series-resonant converter incorporating the proposed MEMS resonator has been presented analytically and verified through experiment. This ZVS condition can be found in terms of the equivalent circuit parameters of the resonator. To the knowledge of the authors, ZVS analysis based on the equivalent electrical circuit model of the thin piezoelectric film resonators has not yet been reported in the literature. A CMOS-compatible fabrication process has been proposed and implemented. In addition, the fabricated devices have been characterized and experimental results are included in this paper. The first contour-mode AlN MEMS resonator with moderately low resonant frequency and motional resistance is reported in this paper with measured resonant frequency and motional resistance of 87.28 MHz and 36.728 Ω, respectively.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Current-Sourced LED Driver Compatible With Fluorescent Lamp Ballasts
    • Authors: Choi; J.;Han, H.;Lee, K.;
      Pages: 4455 - 4466
      Abstract: A light-emitting diode (LED) driver compatible with fluorescent lamp (FL) ballasts is presented for a lamp-only replacement without rewiring the existing lamp fixture. Ballasts have a common function to regulate the lamp current, despite widely different circuit topologies. In this paper, magnetic and electronic ballasts are modeled as nonideal current sources and a current-sourced boost converter, which is derived from the duality, is adopted for the power conversion from ballasts. A rectifier circuit with capacitor filaments is proposed to interface the converter with the four-wire output of the ballast. A digital controller emulates the high-voltage discharge of the FL and operates adaptively with various ballasts. A prototype 20- W LED driver for retrofitting T8 36-W FL is evaluated with both magnetic and electronic ballasts. In addition to wide compatibility, accurate regulation of the LED current within 0.6% error and high driver efficiency over 89.7% are obtained.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Filter Capacitor Minimization in a Flyback LED Driver Considering Input
           Current Harmonics and Light Flicker Characteristics
    • Authors: Shagerdmootaab; A.;Moallem, M.;
      Pages: 4467 - 4476
      Abstract: In this paper, a comprehensive study is conducted on reducing the size of output filter capacitor in an ac–dc flyback converter for driving high-brightness LED strings. To this end, a relationship between the input current harmonics, LED light flicker, and the magnitude of filter capacitor is obtained. It is shown that the size of the filter capacitor is mostly affected by the amplitude of the third and fifth harmonics of input current and the output light flicker. Considering the EN61000-3-2 standard for input current harmonics content and ENERGY STAR standard for flicker requirement, a procedure for obtaining the minimum value of filter capacitance is presented. Experimental studies are performed on an ac–dc flyback LED driver using the proposed method and tested on Cree XLamp XP-G and CR22-32L LED strings.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A High-Power CMOS Class-D Amplifier for Inductive-Link Medical
           Transmitters
    • Authors: Valente; V.;Eder, C.;Donaldson, N.;Demosthenous, A.;
      Pages: 4477 - 4488
      Abstract: Powering of medical implants by inductive coupling is an effective technique, which avoids the use of bulky implanted batteries or transcutaneous wires. On the external unit side, class-D and class-E power amplifiers (PAs) are conventionally used, thanks to their high efficiency at high frequencies. The initial specifications driving this study require the use of multiple independent stimulators, which imposes serious constraints on the area and functionality of the external unit. An integrated circuit class-D PA has been designed to provide both small area and enhanced functionality, the latter achieved by the addition of an on-chip (PLL) a dead-time generator and a phase detector. The PA was designed in a 0.18- $mu$ m CMOS high-voltage process technology and occupies an area of 9.86 mm $^2$ . It works at frequencies up to 14 MHz and 30-V supply and efficiencies higher than 80 $%$ are obtained at 14 MHz. The PA is intended for a closed-loop transmitter system that optimizes power delivery to medical implants.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • High Current Ripple for Power Density and Efficiency Improvement in Wide
           Bandgap Transistor-Based Buck Converters
    • Authors: Cougo; B.;Schneider, H.;Meynard, T.;
      Pages: 4489 - 4504
      Abstract: With the recent development and availability of wide bandgap devices in the market, more and more power converters are being designed with such devices. Given their fast commutation, when compared to their equivalent Si-based counterparts, these new devices allow increasing the converter's efficiency and/or power density. However, in order to fully avail these new devices, one should precisely know their switching characteristics and exploit it the best way possible. This paper recalls our own precise method to measure separately turn-on and turn-off energies of wide bandgap devices. This method is applied to commercially available SiC and GaN transistors and results show that they present much lower turn-off than turn-on energies. For that reason, we show that a SiC-based buck converter must have high current ripple in the output filter inductor in order to decrease transistor losses. Analysis of these losses as well as experimental results are presented. Finally, the precise design of a 2-kW SiC-based buck converter for aircraft applications is performed for different current ripples and switching frequencies. We show that current ripple higher than 250% of the dc load current significantly decreases the converter's losses, and consequently allows the increase of the switching frequency, which reduces the system volume and weight.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Online Detection of High-Resistance Connections in Multiphase Induction
           Machines
    • Authors: Mengoni; M.;Zarri, L.;Tani, A.;Gritli, Y.;Serra, G.;Filippetti, F.;Casadei, D.;
      Pages: 4505 - 4513
      Abstract: High-resistance connections in electrical machines cause unbalances in the stator resistances, reduce the efficiency, and increase the fire hazard. In this paper, the problem of detection of high-resistance connections is investigated for multiphase induction machines with an odd number of phases. The main contribution of this paper is a control scheme that can determine the stator resistance unbalance of all phases, under transient and steady-state operating conditions. The theoretical analysis and the feasibility of the control scheme are confirmed by experimental tests.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Startup Procedure for DSP-Controlled Three-Phase Six-Switch Boost PFC
           Rectifier
    • Authors: Kumar; M.;Huber, L.;Jovanovic, M.M.;
      Pages: 4514 - 4523
      Abstract: In three-phase applications, the six-switch boost power factor correction rectifier is the most widely employed topology because of its good performance and cost effectiveness. A vast amount of literature that deals with this circuit is exclusively focused on various control schemes aimed at optimizing different aspects of its steady-state and/or transient performance. However, almost no literature is available on its startup procedure, which is an indispensable part of control design of any practical circuit. To fill this gap, in this paper, a detailed startup procedure is described. This three-step startup procedure ensures that the inrush currents stay below a specified level and that the output voltage increases monotonically to its reference value, i.e., it does not exhibit any overshoot. The proposed startup procedure is illustrated with MATLAB/Simulink simulation waveforms and also experimentally verified.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Optimal State Reference Computation With Constrained MTPA Criterion for PM
           Motor Drives
    • Authors: Preindl; M.;Bolognani, S.;
      Pages: 4524 - 4535
      Abstract: This research proposes a procedure that maps a PMSM torque request onto optimal state (current) references. Combining the procedure with a dynamic (current) controller yields a torque controller. The maximum torque per ampere (MTPA) criterion is used to minimize conduction and switching losses. This research extends the concept to field-weakening operation to obtain high efficiency at any machine speed. The resulting constrained MTPA criterion is formalized as an optimization problem. Since it is difficult to solve directly, the maximum and intersection torque subproblems are identified. An algorithm is obtained that maps a torque onto an optimal state reference, and it is sufficiently efficient for real-time implementation. This method is compatible with a variety of state (current) controllers with/without PWM, SPM and IPM machines with saliency and reverse saliency, and a variable dc-link voltage. The proposed procedure relies on a sufficiently accurate torque model that may not be provided using rated machine parameters. Thus, an approach to compute locally optimized machine parameters is proposed that takes magnetic saturation into account. The concept is developed on a software-in-the-loop platform and evaluated on an experimental test bench.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • A Fast DC-Bus Voltage Controller for Bidirectional Single-Phase AC/DC
           Converters
    • Authors: Pahlevani; M.;Jain, P.;
      Pages: 4536 - 4547
      Abstract: This paper presents a new dc-bus voltage control technique for single-phase bidirectional ac/dc converters. The proposed controller is able to significantly improve the transient response of the dc-bus voltage control loop and provide a robust and reliable closed-loop control system. In the proposed approach, the dc value of the dc-bus voltage is precisely estimated through a specific adaptive filter. The structure of the proposed filter provides a very fast and robust estimation for the dc value of the dc-bus voltage. In particular, the proposed dc-extraction technique is able to precisely estimate the dc value in presence of double-frequency ripple mounted on top of the dc-bus voltage in single-phase ac/dc converters. Simulation and experimental results demonstrate the superior performance of the proposed closed-loop control system compared to the conventional ones.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Dithering Digital Ripple Correlation Control for Photovoltaic Maximum
           Power Point Tracking
    • Authors: Barth; C.;Pilawa-Podgurski, R.C.N.;
      Pages: 4548 - 4559
      Abstract: This study demonstrates a new method for rapid and precise maximum power point tracking in photovoltaic (PV) applications using dithered PWM control. Constraints imposed by efficiency, cost, and component size limit the available PWM resolution of a power converter, and may in turn limit the MPP tracking efficiency of the PV system. In these scenarios, PWM dithering can be used to improve average PWM resolution. In this study, we present a control technique that uses ripple correlation control (RCC) on the dithering ripple, thereby achieving simultaneous fast tracking speed and high tracking accuracy. Moreover, the proposed method solves some of the practical challenges that have to date limited the effectiveness of RCC in solar PV applications. We present a theoretical derivation of the principles behind dithering digital ripple correlation control, as well as experimental results that show excellent tracking speed and accuracy with basic hardware requirements.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Circular Switching Surface Technique: High-Performance Constant Power Load
           Stabilization for Electric Vehicle Systems
    • Authors: Anun; M.;Ordonez, M.;Zurbriggen, I.G.;Oggier, G.G.;
      Pages: 4560 - 4572
      Abstract: Electric vehicles make use of energy storage systems, such as batteries and/or ultracapacitors to power the electric power drive train, as well as auxiliary automotive system for control, safety, and comfort. This relatively complex power structure can be described as a distributed multiconverter system. The constant power behavior of tight-speed controllers in the vehicle's traction system and tightly regulated dc–dc converters connected to the HV-DC bus produces instability effects. This paper proposes a simple and practical geometric control, using circular switching surfaces, to address constant power load instability in electric vehicle's power systems. The proposed switching surfaces provide a solution in the geometrical domain to constant power loading conditions, while achieving outstanding dynamic response compared to state-of-the-art controllers. The controller is implemented in a bidirectional Buck + Boost cascade converter as a battery charge/discharge unit and ensures reliable system operation. The predictable and consistent behavior of the converter with constant power load is presented by analyzing the system curves in the normalized state plane with the switching surfaces employed. Simulation and experimental results on a scaled 1-kW Buck + Boost cascade converter validate the proposed switching surfaces and predictions regarding the converter's behavior under constant power loading conditions.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Control of Transient Power During Unintentional Islanding of Microgrids
    • Authors: Issa; W.R.;Abusara, M.A.;Sharkh, S.M.;
      Pages: 4573 - 4584
      Abstract: In inverter-based microgrids, the paralleled inverters need to work in grid-connected mode and stand-alone mode and to transfer seamlessly between the two modes. In grid-connected mode, the inverters control the amount of power injected into the grid. In stand-alone mode, however, the inverters control the island voltage while the output power is dictated by the load. This can be achieved using the droop control. Inverters can have different power set points during grid-connected mode, but in stand-alone mode, they all need their power set points to be adjusted according to their power ratings. However, during sudden unintentional islanding (due to loss of mains), transient power can flow from inverters with high power set points to inverters with low power set points, which can raise the dc-link voltage of the inverters causing them to shut down. This paper investigates the transient circulating power between paralleled inverters during unintentional islanding and proposes a controller to limit it. The controller monitors the dc-link voltage and adjusts the power set point in proportion to the rise in the voltage. A small-signal model of an islanded microgrid is developed and used to design the controller. Simulation and experimental results are presented to validate the design.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Deadbeat Control for Electrical Drives: A Robust and Performant Design
           Based on Differential Flatness
    • Authors: Stumper; J.;Hagenmeyer, V.;Kuehl, S.;Kennel, R.;
      Pages: 4585 - 4596
      Abstract: The present contribution introduces a new deadbeat controller design that increases robustness without compromising performance. In conventional deadbeat control, feedback linearization is applied, and the feedback gains are set very high to obtain the minimum-step reference response. This makes the control method highly sensitive to parametric uncertainties. To date, the only remedies have been to tune the deadbeat controller settling time higher and the according disturbance estimator more slowly. Recently proposed remedies based on online parameter estimators show either moderate performance or higher demands on hardware. Therefore, first a feedforward linearization-based controller is introduced to obtain the desired reference response via open-loop control. Thereby, the parametric sensitivity is considerably improved. Then, the new generalized flatness-based controller, a mix between feedback and feedforward linearization, is proposed. The result is a deadbeat controller with high dynamic performance and high robustness with respect to both parameter uncertainties and disturbances. The experimental results on an induction machine demonstrate very fast reference tracking, high robustness to typical parameter uncertainties, and active compensation of time-varying disturbances. The results on a synchronous reluctance machine show that even very large inductance uncertainties can be handled.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Modeling and Stability Analysis of Islanded DC Microgrids Under Droop
           Control
    • Authors: Tahim; A.P.N.;Pagano, D.J.;Lenz, E.;Stramosk, V.;
      Pages: 4597 - 4607
      Abstract: The stability of dc microgrids (MGs) depends on the control strategy adopted for each mode of operation. In an islanded operation mode, droop control is the basic method for bus voltage stabilization when there is no communication among the sources. In this paper, it is shown the consequences of droop implementation on the voltage stability of dc power systems, whose loads are active and nonlinear, e.g., constant power loads. The set of parallel sources and their corresponding transmission lines are modeled by an ideal voltage source in series with an equivalent resistance and inductance. This approximate model allows performing a nonlinear stability analysis to predict the system qualitative behavior due to the reduced number of differential equations. Additionally, nonlinear analysis provides analytical stability conditions as a function of the model parameters and it leads to a design guideline to build reliable (MGs) based on safe operating regions.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
  • Application Criteria for Nine-Switch Power Conversion Systems with
           Improved Thermal Performance
    • Authors: Qin; Z.;Loh, P.C.;Blaabjerg, F.;
      Pages: 4608 - 4620
      Abstract: Nine-switch converter is a reduced-switch equivalence of the widely used 12-switch back-to-back converter. Like other reduced-switch topologies, the nine-switch converter experiences operating constraints, which may limit its efficiency. This is, however, not universal, meaning losses of the nine-switch converter can at times be lower than the 12-switch back-to-back converter. The scope of this paper is, thus, to identify application criteria for the nine-switch converter, which upon met, will lead to lower conduction and hence total losses. Loss distribution among switches of the nine-switch converter is also investigated, since it can greatly influence reliability of the overall converter. Experimental results obtained have promptly justified the analytical reasoning formulated.
      PubDate: Aug. 2015
      Issue No: Vol. 30, No. 8 (2015)
       
 
 
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