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  Subjects -> ELECTRONICS (Total: 152 journals)
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 5)
Advances in Microelectronic Engineering     Open Access   (Followers: 1)
Advances in Power Electronics     Open Access   (Followers: 8)
Aerospace and Electronic Systems, IEEE Transactions on     Hybrid Journal   (Followers: 59)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 10)
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: 8)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 15)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Biomedical Instrumentation & Technology     Full-text available via subscription   (Followers: 4)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 5)
BULLETIN of National Technical University of Ukraine. Series RADIOTECHNIQUE. RADIOAPPARATUS BUILDING     Open Access   (Followers: 1)
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: 2)
Circuits and Systems     Open Access   (Followers: 9)
Consumer Electronics Times     Open Access   (Followers: 4)
Control Systems     Hybrid Journal   (Followers: 21)
Electronic Markets     Hybrid Journal   (Followers: 6)
Electronic Materials Letters     Hybrid Journal   (Followers: 3)
Electronics     Open Access   (Followers: 7)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 5)
Electronics Letters     Hybrid Journal   (Followers: 17)
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 18)
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: 20)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 14)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 13)
IEEE Consumer Electronics Magazine     Full-text available via subscription   (Followers: 11)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 9)
IEEE Journal of the Electron Devices Society     Open Access   (Followers: 2)
IEEE Power Electronics Magazine     Full-text available via subscription   (Followers: 5)
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: 22)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 13)
IEEE Transactions on Electron Devices     Hybrid Journal   (Followers: 6)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 13)
IEEE Transactions on Power Electronics     Hybrid Journal   (Followers: 15)
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: 7)
IET Wireless Sensor Systems     Hybrid Journal   (Followers: 6)
IETE Journal of Education     Open Access   (Followers: 2)
IETE Journal of Research     Open Access   (Followers: 8)
IETE Technical Review     Open Access   (Followers: 3)
Industrial Electronics, IEEE Transactions on     Hybrid Journal   (Followers: 11)
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: 1)
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: 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: 12)
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   (Followers: 1)
International Journal of Numerical Modelling:Electronic Networks, Devices and Fields     Hybrid Journal   (Followers: 2)
International Journal of Power Electronics     Hybrid Journal   (Followers: 4)
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 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  
ISRN Electronics     Open Access   (Followers: 1)
ISRN Signal Processing     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     Full-text available via subscription   (Followers: 1)
Journal of Electromagnetic Analysis and Applications     Open Access   (Followers: 4)

        1 2 | Last

IEEE Transactions on Power Electronics     [SJR: 3.308]   [H-I: 111]
   [17 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  [175 journals]
  • Table of Contents
    • Pages: C1 - C2
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • IEEE Transactions on Power Electronics publication information
    • Pages: C2 - C2
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • IEEE Power Electronics Society Information
    • Pages: C3 - C3
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • A Systematic Approach to Design High-Order Phase-Locked Loops
    • Authors: Golestan; S.;Freijedo, F.D.;Guerrero, J.M.;
      Pages: 2885 - 2890
      Abstract: A basic approach to improve the performance of phase-locked loop (PLL) under adverse grid condition is to incorporate a first-order low-pass filter (LPF) into its control loop. The first-order LPF, however, has a limited ability to suppress the grid disturbances. A natural thought to further improve the disturbance rejection capability of PLL is to use high-order LPFs. Application of high-order LPFs, however, results in high-order PLLs, which rather complicates the PLL analysis and design procedure. To overcome this challenge, a systematic method to design high-order PLLs is presented in this letter. The suggested approach has a general theme, which means it can be applied to design the PLL control parameters regardless of the order of in-loop LPF. The effectiveness of suggested design method is confirmed through different design cases.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • High-Mobility Stable 1200-V, 150-A 4H-SiC DMOSFET Long-Term Reliability
           Analysis Under High Current Density Transient Conditions
    • Authors: Schrock; J.A.;Ray II, W.B.;Lawson, K.;Bilbao, A.;Bayne, S.B.;Holt, S.L.;Cheng, L.;Palmour, J.W.;Scozzie, C.;
      Pages: 2891 - 2895
      Abstract: For SiC DMOSFETs to obtain widespread usage in power electronics their long-term operational ability to handle the stressful transient current and high temperatures common in power electronics needs to be further verified. To determine the long-term reliability of a single 4H-SiC DMOSFET, the effects of extreme high current density were evaluated. The 4H-SiC DMOSFET has an active conducting area of 40 mm2, and is rated for 1200 V and 150 A. The device was electrically stressed by hard-switching transient currents in excess of four times the given rating (>600 A) corresponding to a current density of 1500 A/cm2. Periodically throughout testing, several device characteristics including $R_{{bf DS}({bf on})}$ and $V_{{bf GS}({bf th})}$ were measured. After 500 000 switching cycles, the device showed a 6.77% decrease in $R_{{bf DS}({bf on})}$ , and only a 132-mV decreased in $V_{{bf GS}({bf th})}$ . Additionally, the dc characteristics of the device were analyzed from 25 to 150 °C and revealed a 200-mV increase in on-state voltage drop at 20 A and a 2-V reduction in $V_{{bf GS}({bf th})}$ at 150 °C. These results show this SiC DMOSFET has robust long-term reliability in high-power applications that are susceptible to pulse over currents, such as pulsed power modulators and hard-switched power electronics.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Carrier-Based Discontinuous PWM Method for Vienna Rectifiers
    • Authors: Lee; J.;Lee, K.;
      Pages: 2896 - 2900
      Abstract: Vienna rectifiers, which are nongenerative-boost types of rectifiers, are used in grid-connected applications with a unity power factor such as telecommunication systems and wind turbine systems. These rectifiers are advantageous in that they have low total harmonic distortion and efficiency. There are many switching methods, which are different from those of three-level topologies, for Vienna rectifiers. In this paper, we propose a carrier-based discontinuous pulse width modulation (CB-DPWM) method. This method is simple compared to the discontinuous PWM (DPWM) method for Vienna rectifiers based on space vectors and guarantees normal rectifier operation for all modulation index ( ${bf M}_{bf a}$ ) values. We perform experiments to verify the suitability and performance of the proposed CB-DPWM method.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • High-Efficiency Two-Inductor PFC Boost Converter Employing SPDT Relay
    • Authors: Kim; C.;Yang, D.;Lee, J.;Moon, G.;
      Pages: 2901 - 2904
      Abstract: A new high-efficiency two-inductor boost converter is proposed in this letter. The proposed converter has topology variation characteristic by an additional single-pole double-throw relay. By operating a two-phase interleaved boost converter at ac low line input and single-boost converter with two series-connected inductors at ac high line input, the proposed converter efficiently utilizes two inductors and switching components. Therefore, the proposed converter can be optimally designed and its efficiency can be maximized at the respective ac input range. The proposed converter can be the most attractive solution for high-efficiency server power supply and other universal input power-factor-correction applications.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • A Component-Minimized Single-Phase Active Power Decoupling Circuit With
           Reduced Current Stress to Semiconductor Switches
    • Authors: Tang; Y.;Blaabjerg, F.;
      Pages: 2905 - 2910
      Abstract: This letter proposes a novel circuit topology which can realize the power decoupling function without adding additional active switches into the circuit. The dc-link capacitor of a full bridge rectifier is split into two identical parts and the midpoint is connected to one leg through a filter inductor. With such a configuration, this leg can control the current going into the two output capacitors connected in series for power decoupling, and the other leg can control the line current according to active and reactive power requirement. The proposed topology does not require additional passive component, e.g., inductors or film capacitors for ripple energy storage because this task can be accomplished by the dc-link capacitors, and therefore its implementation cost can be minimized. Another unique feature of the proposed topology is that the current stress of power semiconductors can be reduced as compared to other existing active power decoupling circuits. This feature becomes more obvious when the converter operates with capacitive load, e.g., for grid voltage support. The operational principle of the proposed circuit is discussed, and experimental results are presented to show the effectiveness of the proposed circuit concept.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Using Current Surface Probe to Measure the Current of the Fast Power
           Semiconductors
    • Authors: Li; K.;Videt, A.;Idir, N.;
      Pages: 2911 - 2917
      Abstract: With the advantage of high bandwidth and small insertion impedance, a current surface probe (CSP) used to measure switching current waveforms is presented in this letter. Its transfer impedance is characterized and validated by measuring an IGBT switching current that is compared with those obtained with a current probe and a Hall effect current probe. Furthermore, by comparing with a current shunt to measure a GaN-HEMT switching current, it is shown that CSP is able to measure a switching current of a few nanoseconds, while it brings no influence on transistor voltage waveform measurement. The obtained results show that the use of CSP brings little parasitic inductances in the measurement circuit and it does not bring the connection of the ground to the power converter.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Direct Power Control Based on Natural Switching Surface for Three-Phase
           PWM Rectifiers
    • Authors: Ge; J.;Zhao, Z.;Yuan, L.;Lu, T.;He, F.;
      Pages: 2918 - 2922
      Abstract: In this letter, the natural trajectories of the output voltage and the inductor currents for three-phase pulse width modulation rectifiers are presented. On this basis, a novel direct power control (DPC) using the natural switching surface is proposed by combining DPC with the boundary control. Compared to the conventional DPC, the proposed control considers the output voltage when selecting the switching states. Therefore, the proposed control does not need an outer voltage control loop and can highly improve the dynamic performance of the dc output voltage. The experimental results on a 1.5-kW prototype confirm the correctness of the theoretical analysis. They verify the feasibility and the validity of the proposed control and show the excellent dynamic performance.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Double-Input Bidirectional DC/DC Converter Using Cell-Voltage Equalizer
           With Flyback Transformer
    • Authors: Anno; T.;Koizumi, H.;
      Pages: 2923 - 2934
      Abstract: In this paper, a double-input bidirectional dc/dc converter that uses a rechargeable battery and an ultracapacitor (UC) is proposed. This converter is connected to a cell-voltage equalizer between the battery and UC. The cell-voltage equalizer enables cell-voltage equalization and energy transfer between the battery and UC. This converter has six operational modes. These modes are investigated by reduced-power-scale circuit experiment. In addition, the circuit operation under the combination of the six modes is verified using a PSIM simulator in a large power scale.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Three-Level Single-Phase Bridgeless PFC Rectifiers
    • Authors: Lange; A.D.B.;Soeiro, T.B.;Ortmann, M.S.;Heldwein, M.L.;
      Pages: 2935 - 2949
      Abstract: This paper presents new three-level unidirectional single-phase PFC rectifier topologies well suited for applications targeting high efficiency and/or high power density. The characteristics of a selected novel rectifier topology including its principles of operation, modulation strategy, feedback control scheme, and a power circuit design related analysis are presented. Finally, a 220-V/3-kW laboratory prototype is constructed and used in order to verify the characteristics of the new converter, which include remarkably low switching losses and single ac-side boost inductor, that allow for a 98.6% peak efficiency with a switching frequency of 140 kHz.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Real-Time Prediction of Power Electronic Device Temperatures Using
           PRBS-Generated Frequency-Domain Thermal Cross Coupling Characteristics
    • Authors: Davidson; J.N.;Stone, D.A.;Foster, M.P.;
      Pages: 2950 - 2961
      Abstract: This paper presents a technique to predict the temperature response of a multielement thermal system based on the thermal cross coupling between elements. The complex frequency-domain cross coupling of devices is first characterized using a pseudorandom binary sequence technique. The characteristics are then used to predict device temperatures for a known input power waveform using a discrete Fourier transform-based technique. The resulting prediction shows good agreement with an example practical system used for evaluation. To reduce the computational complexity of the initial method, a digital infinite impedance response (IIR) filter is fitted to each cross coupling characteristic. A high correlation fit is demonstrated that produces a near-identical temperature response compared to the initial procedure while requiring fewer mathematical operations. Experimental validation on the practical system shows good agreement between IIR filter predictions and practical results. It is further demonstrated that this agreement can be substantially improved by taking feedback from an internal reference temperature. Additionally, the proposed IIR filter technique allows the efficient calculation of future device temperatures based on simulated input, facilitating future temperature predictions.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Space-Vector Versus Nearest-Level Pulse Width Modulation for Multilevel
           Converters
    • Authors: Deng; Y.;Harley, R.G.;
      Pages: 2962 - 2974
      Abstract: This paper studies the inherent relationship between two widely used pulse width modulation (PWM) methods for multilevel converters, i.e., the space vector modulation (SVM) method, also called space vector pulse width modulation, and the nearest-level modulation method. The nearest-level modulation method directly controls the voltage of each phase, while the SVM method simultaneously deals with all phases. It is demonstrated in this paper that the two modulation methods are functionally equivalent: with proper common-mode voltage injections, the nearest-level modulation method is equivalent to the SVM method; by selecting the appropriate redundant switching sequences and the corresponding duty cycles, the SVM method is equivalent to the nearest-level modulation method. Nevertheless, the SVM method can conveniently provide more flexibility of optimizing the switching patterns, without the need of designing sophisticated common-mode voltages. An efficient and flexible modulation method for any multiphase multilevel converter is, therefore, proposed, which combines the advantages of the nearest-level modulation and the SVM methods, i.e., both with less computational burden and high flexibility of optimizing the output waveforms. Simulation and experimental results validate the analysis.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Liquid Jet Impingement Cooling of a Silicon Carbide Power Conversion
           Module for Vehicle Applications
    • Authors: Gould; K.;Cai, S.Q.;Neft, C.;Bhunia, A.;
      Pages: 2975 - 2984
      Abstract: Thermal management of power electronics is an extremely challenging problem in the harsh environment of military hybrid vehicles, where the local air and liquid coolant's temperature exceed 100 °C under regular operating conditions. This paper presents the development work of a high heat flux, jet impingement-cooled heat exchanger for a 600-V/50-A silicon carbide (SiC) power module (rated at 175 °C device junction temperature), used for bidirectional power conversion between a 28-V battery and a 300-V dc bus. A total of 50 volume% mixture of water–ethylene glycol (WEG) coolant at 100 °C inlet temperature is the only available coolant. An array of WEG coolant microjets impinges on the base plate of the SiC module. The jet impingement cooling system has been optimized by experimental studies on a surrogate module, along with a high-fidelity computational model, to accurately estimate the SiC device junction temperature in relevant operating conditions. Results indicate that at the design heat load of 151 W (worst-case scenario), the SiC device junction temperature is reduced from 290 °C with commercial-off-the-shelf (COTS) cold plate cooling and 215 °C with COTS microchannel heat exchanger cooling, to 169 °C with a jet impingement-cooled heat exchanger, using the same flow rate.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Hybrid Phase-Shift-Controlled Three-Level and LLC
           DC–DC Converter With Active Connection at the Secondary Side
    • Authors: Guo; Z.;Sha, D.;Liao, X.;
      Pages: 2985 - 2996
      Abstract: This paper proposes a hybrid phase-shift-controlled three-level (TL) and LLC dc–dc converter. The TL dc–dc converter and LLC dc–dc converter have their own transformers. Compared with conventional half-bridge TL dc–dc converters, the proposed one has no additional switch at the primary side of the transformer, where the TL converter shares the lagging switches with the LLC converter. At the secondary side of the transformers, the TL and LLC converters are connected by an active switch. With the aid of the LLC converter, the zero voltage switching (ZVS) of the lagging switches can be achieved easily even under light load conditions. Wide ZVS range for all the switches can be ensured. Both the circulating current at the primary side and the output filter inductance are reduced. Furthermore, the efficiency of the converter is improved dramatically. The features of the proposed converter are analyzed, and the design guidelines are given in the paper. Finally, the performance of the converter is verified by a 1-kW experimental prototype.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Automatic Current Sharing of an Input-Parallel Output-Parallel
           (IPOP)-Connected DC–DC Converter System With Chain-Connected
           Rectifiers
    • Authors: Shi; J.;Liu, T.;Cheng, J.;He, X.;
      Pages: 2997 - 3016
      Abstract: Input-parallel output-parallel (IPOP)-connected converter systems allow the use of low-power converter modules for high-power applications. An IPOP converter topology with half-wave, daisy chain-connected rectifiers is presented which consists of multiple half-bridge (HB) dc–dc converter modules. By utilizing a common-duty-ratio control scheme, without a dedicated current-sharing controller, automatic sharing of input current and load current in the IPOP converter is achieved even in the presence of differences of more than 10% in various module parameters. The steady-state and dynamic-state current-sharing performance of the proposed IPOP converter is analyzed by using a steady-state dc model and a small-signal model of the system, respectively. It is concluded that steady-state current sharing among modules can be realized by applying a common-duty-ratio control scheme and by reducing the difference in transformer turn ratios, while dynamic-state current sharing is only slightly affected by substantial module parameter mismatches. The stability and current-sharing performance are verified by Saber simulation and an 800-W prototype consisting of two HB modules. The IPOP converter topology under the common-duty-ratio scheme can be extended to any system of three or more converter modules, including full-bridge dc–dc converters.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • A Step-up Resonant Converter for Grid-Connected Renewable Energy Sources
    • Authors: Chen; W.;Wu, X.;Yao, L.;Jiang, W.;Hu, R.;
      Pages: 3017 - 3029
      Abstract: With the rapid development of large-scale renewable energy sources and HVDC grid, it is a promising option to connect the renewable energy sources to the HVDC grid with a pure dc system, in which high-power high-voltage step-up dc–dc converters are the key equipment to transmit the electrical energy. This paper proposes a resonant converter which is suitable for grid-connected renewable energy sources. The converter can achieve high voltage gain using an LC parallel resonant tank. It is characterized by zero-voltage-switching (ZVS) turn-on and nearly ZVS turn-off of main switches as well as zero-current-switching turn-off of rectifier diodes; moreover, the equivalent voltage stress of the semiconductor devices is lower than other resonant step-up converters. The operation principle of the converter and its resonant parameter selection is presented in this paper. The operation principle of the proposed converter has been successfully verified by simulation and experimental results.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Infinity-Norm of Impedance-Based Stability Criterion for Three-Phase AC
           Distributed Power Systems With Constant Power Loads
    • Authors: Liu; Z.;Liu, J.;Bao, W.;Zhao, Y.;
      Pages: 3030 - 3043
      Abstract: This paper presents a stability criterion for three-phase AC distributed power system (DPS). While the source output impedance and the load input admittance under synchronous reference frame are generally investigated to predict the stability of the three-phase AC DPS, the infinity-norms of the impedance and admittance are innovatively adopted in the proposed criterion to improve the computational complexity and the conservatism. Meanwhile, the computational complexity and the conservatism of the proposed criterion are analyzed and compared with existing ones. Furthermore, the terminal characteristics of the studied three-phase AC DPS composed of an LC filter and a three-phase boost rectifier, which cover the source output impedance and the load input admittance, are comprehensively modeled. Finally, the effectiveness of the proposed criterion is validated by experimental results.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Research on Unbalanced-Load Correction Capability of Two Power Electronic
           Transformer Topologies
    • Authors: Wang; X.;Liu, J.;Ouyang, S.;Meng, F.;
      Pages: 3044 - 3056
      Abstract: Compared with conventional power transformer, power electronic transformer (PET) has many merits and an increasing possibility to replace it in the future. In this paper, the unbalanced-load correction capability of two H-bridge based three-phase three-stage modular PET topologies, the separate-phase-connection (SPC) one and the cross-phase-connection (CPC) one, are analyzed and compared. Both of the SPC and CPC consist of three stages: a modular multilevel ac–dc input stage, an isolation stage with several independent modular dual active bridge (DAB) dc–dc converters, and a dc–ac output stage with single-phase-inverter parallel-connected structure. Based on the control strategy, it is found that the SPC is suitable for dealing with full-range unbalanced load under the condition of increasing the input-stage current stress. For the SPC feeding, one load or three loads with identical power polarity, the current stress shall be theoretically increased up to 115% of the rated one, while the percentage is 153% when the SPC feeds three loads with different power polarity. On the contrary, the CPC is only suitable for dealing with partial unbalanced-load conditions. Extendedly, the third so-called full-range-power auto-balance PET is proposed to deal with unbalanced load, the performance of which is verified by simulation results. A downscaled prototype for SPC and CPC is built and tested. Experimental results verify the unbalanced-load correction performance of SPC and CPC.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Evaluation of a New Remote Sensing Method for Onboard Voltage Regulator in
           Computing System
    • Authors: Liang; X.;Wong, H.;Uan-Zo-li, A.;Zhou, X.;
      Pages: 3057 - 3067
      Abstract: Differential remote sensing has been popularly used in voltage regulator (VR) design for many years to ensure a high regulation accuracy requirement for processor supply voltage. One new remote sensing method by using normal VR controller is proposed in this paper to achieve similar high regulation accuracy as that by using true differential remote sensing method for output voltage. Working principles of the proposed method are analyzed in detail for normal VR controller with individual ground and combined ground, respectively. Advantages, design considerations, and application constraints for it are analyzed in detail as well. Finally, test is conducted for normal VR controllers with individual ground and combined ground to verify its effectiveness.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Three-Port DC–DC Converter for Stand-Alone Photovoltaic Systems
    • Authors: Hu; Y.;Xiao, W.;Cao, W.;Ji, B.;Morrow, D.J.;
      Pages: 3068 - 3076
      Abstract: System efficiency and cost effectiveness are of critical importance for photovoltaic (PV) systems. This paper addresses the two issues by developing a novel three-port dc–dc converter for stand-alone PV systems, based on an improved Flyback-Forward topology. It provides a compact single-unit solution with a combined feature of optimized maximum power point tracking (MPPT), high step-up ratio, galvanic isolation, and multiple operating modes for domestic and aerospace applications. A theoretical analysis is conducted to analyze the operating modes followed by simulation and experimental work. This paper is focused on a comprehensive modulation strategy utilizing both PWM and phase-shifted control that satisfies the requirement of PV power systems to achieve MPPT and output voltage regulation. A 250-W converter was designed and prototyped to provide experimental verification in term of system integration and high conversion efficiency.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Bidirectional PWM Converter Integrating Cell Voltage Equalizer Using
           Series-Resonant Voltage Multiplier for Series-Connected Energy Storage
           Cells
    • Authors: Uno; M.;Kukita, A.;
      Pages: 3077 - 3090
      Abstract: In conventional energy storage systems using series-connected energy storage cells such as lithium-ion battery cells and supercapacitors (SCs), an interface bidirectional converter and cell voltage equalizer are separately required to manage charging/discharging and ensure years of safe operation. In this paper, a bidirectional PWM converter integrating cell voltage equalizer is proposed. This proposed integrated converter can be derived by combining a traditional bidirectional PWM converter and series-resonant voltage multiplier (SRVM) that functionally operates as an equalizer and is driven by asymmetric square wave voltage generated at the switching node of the converter. The converter and equalizer can be integrated into a single unit without increasing the switch count, achieving not only system-level but also circuit-level simplifications. Open-loop control is feasible for the SRVM when operated in discontinuous conduction mode, meaning the proposed integrated converter can operate similarly to conventional bidirectional converters. An experimental charge–discharge cycling test for six SCs connected in series was performed using the proposed integrated converter. The cell voltage imbalance was gradually eliminated by the SRVM while series-connected SCs were cycled by the bidirectional converter. All the cell voltages were eventually unified, demonstrating the integrated functions of the proposed converter.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Single-Switch Voltage Equalizer Using Multistacked Buck–Boost
           Converters for Partially Shaded Photovoltaic Modules
    • Authors: Uno; M.;Kukita, A.;
      Pages: 3091 - 3105
      Abstract: Partial shading on a photovoltaic (PV) string comprising multiple modules/substrings triggers issues such as a significant reduction in power generation and the occurrence of multiple maximum power points (MPPs), including a global and local MPPs, that encumber MPP tracking algorithms. Single-switch voltage equalizers using multistacked buck–boost converters are proposed to settle the partial shading issues. The single-switch topology can considerably simplify the circuitry compared with conventional equalizers requiring multiple switches in proportion to the number of PV modules/substrings. The proposed voltage equalizers can be derived by stacking capacitor–inductor–diode filters on traditional buck–boost converters, such as SEPIC, Zeta, and Ćuk converters. The optimum equalization strategy is also proposed and discussed for the equalizers to compensate the partially shaded PV modules efficiently. Operational analysis based on a simplified equivalent circuit is performed for a SEPIC-based topology. Experimental equalization tests using the SEPIC-based voltage equalizer were performed emulating partially shaded conditions for a PV panel comprising of three substrings. Local MPPs were eliminated and extractable maximum powers increased by the equalizer, demonstrating the efficacy of the proposed voltage equalizer.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Islanding Detection Search Sequence for Distributed Power Generators Under
           AC Grid Faults
    • Authors: Serban; E.;Pondiche, C.;Ordonez, M.;
      Pages: 3106 - 3121
      Abstract: Grid-connected converters require advanced controllers in order to achieve high performance and meet country-specific anti-islanding standards. This paper presents a novel, high performance islanding search sequence (ISS) technique applied to four islanding detection methods. The salient aspects of the proposed determination technique reside in its fault-tolerant safety redundancy with rapid unintentional islanding detection integrated within: active–reactive power control, maximum power point tracking (MPPT) algorithm, and phase-locked loop routine. The islanding detection search sequence method is successfully implemented within a voltage-oriented inverter controller using a synchronously rotating reference frame. The ISS structure is designed with an adaptive strategy to achieve system stability and minimum impact on power quality, and is applicable to grid-connected distributed power generators. The adaptive search sequence results in fast detection, robust operation, and most importantly, a reduced reactive and active power injection. The proposed control structure and detection methods performance are demonstrated through experimental results of a three-phase, 20-kVA three-level neutral-point-clamped transformerless inverter. The evaluation results on the grid-interactive inverter include the islanding detection method integrated in the MPPT used in renewable energy harvesting applications.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • A Quasi-Unipolar SPWM Full-Bridge Transformerless PV Grid-Connected
           Inverter with Constant Common-Mode Voltage
    • Authors: Xiao; H.F.;Lan, K.;Zhang, L.;
      Pages: 3122 - 3132
      Abstract: The unipolar sinusoidal pulsewidth modulation (SPWM) full-bridge transformerless photovoltaic inverter with ac bypass brings low conduction loss and low leakage current. In order to better eliminate the leakage current induced by the common-mode voltage, the clamping technology can be adopted to hold the common-mode voltage on a constant value in the freewheeling period. A full-bridge inverter topology with constant common-mode voltage (FB-CCV) has been derived and proposed in this paper, two unidirectional freewheeling branches are added into the ac side of the FB-CCV, and the split structure of the proposed freewheeling branches does not lead itself to the reverse-recovery issues for the freewheeling power switches and as such superjunction MOSFETs can be utilized without any efficiency penalty. The passive clamping branches consist of a capacitor divider and two diodes, is added into the dc side of the FB-CCV, therefore, the weakness of active damping branch has been overcome, and the better clamping performance has been achieved in the freewheeling period. In the dead time between the main switches and the freewheeling switches, the antiparallel diodes of diagonal main switches of the FB-CCV form the freewheeling path to clamp the common-mode voltage at a constant value, and a quasi-unipolar SPWM strategy is presented. The operation principle, differential-mode, and common-mode characteristics of the FB-CCV, Heric, H6, and HB-ZVR topologies are analyzed and compared in detail. Finally, the viability of the FB-CCV is verified by a universal prototype inverter rated at 5 kW.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • An Improved Droop Control Strategy for Reactive Power Sharing in Islanded
           Microgrid
    • Authors: Han; H.;liu, y.;Sun, Y.;Su, M.;Guerrero, J.M.;
      Pages: 3133 - 3141
      Abstract: For microgrid in islanded operation, due to the effects of mismatched line impedance, the reactive power could not be shared accurately with the conventional droop method. To improve the reactive power sharing accuracy, this paper proposes an improved droop control method. The proposed method mainly includes two important operations: error reduction operation and voltage recovery operation. The sharing accuracy is improved by the sharing error reduction operation, which is activated by the low-bandwidth synchronization signals. However, the error reduction operation will result in a decrease in output voltage amplitude. Therefore, the voltage recovery operation is proposed to compensate the decrease. The needed communication in this method is very simple, and the plug-and-play is reserved. Simulations and experimental results show that the improved droop controller can share load active and reactive power, enhance the power quality of the microgrid, and also have good dynamic performance.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Improving the Scavenged Power of Nonlinear Piezoelectric Energy Harvesting
           Interface at Off-Resonance by Introducing Switching Delay
    • Authors: Hsieh; P.;Chen, C.;Chen, H.;
      Pages: 3142 - 3155
      Abstract: This paper presents two interface circuit designs that improve the piezoelectric energy harvesting performance at off-resonance. Complex impedance matching at different frequencies is achieved by introducing delay into the conventional switching methods. The proposed techniques can also be used in other applications, such as electromagnetic energy harvesting. The system is analyzed using equivalent impedance at fundamental of operating frequency. Design considerations such as two possible modes of operation, sensitivity to voltage and timing errors, loss due to nonlinear operations, and conduction loss of switches are detailed. As compared with the conventional methods, analytical results show that, with the electromechanical coupling coefficient $k_e^2$ of 0.076 and the mechanical damping ratio $zeta _m$ of 0.02, the proposed techniques can improve the 3-dB bandwidth by $76%$ with a flipping quality factor of $10$ . Experimental results with a commercially available piezoelectric device show a $23%$ improvement in 3-dB bandwidth and a $66%$ improvement in extracted power with $5%$ of frequency mismatch.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • A Family of Zero-Current-Transition Transformerless Photovoltaic
           Grid-Connected Inverter
    • Authors: Xiao; H.F.;Lan, K.;Zhou, B.;Zhang, L.;Wu, Z.;
      Pages: 3156 - 3165
      Abstract: Low leakage current and high efficiency are two key indexes for transformerless PV grid-connected inverter. The transformerless inverter topologies have superior efficiency thanks to saving transformer, but their semiconductor devices are still on hard-switching state at present. First and foremost, a novel zero-current-transition (ZCT) concept for the single-phase full-bridge transformerless PV grid-connected inverters is presented in this paper. Second, the zero-current turn-off for high-frequency main switches of the inverters and the zero-current turn-on for auxiliary switches added are achieved by introducing two resonant tanks. Furthermore, a family of ZCT transformerless grid-connected inverters with sinusoidal pulse width modulation is deduced. Especially, taking zero-current-transition six-switch full-bridge topology (ZCT-H6-I) as an example, its operation principle, soft-switching conditions, duty cycle constraints, and parameter design procedure of the resonant tank are analyzed in detail. Finally, the validity of the ZCT concept is verified by a ZCT-H6-I prototype rated at 50 kHz, 1 kW.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Improving the Regulation Range of EV Battery Chargers With
           L3C2 Resonant Converters
    • Authors: Shafiei; N.;Ordonez, M.;
      Pages: 3166 - 3184
      Abstract: The demand for electric vehicles has expanded rapidly for both industrial and transportation applications. In parallel, new battery technologies capable of deeply discharging and powering electric vehicles over long periods of time have been introduced and made available in the market. Due to the increasing complexity of charging algorithms, battery chargers are exposed to demanding operating requirements. Chargers should not only work under different loading conditions (from absolutely zero to maximum output power) but also regulate a wide output voltage range (from near zero to 1.5 times nominal voltage). In this paper, a multiresonant $L3C2$ resonant converter is introduced that can cover nearly all of the regions in the battery V–I plane, from near zero output voltage, zero output current to maximum output power. By adding one capacitor, the topology is able to extend the operating frequency beyond the ${{{bm LLC}}}$ topology and achieve significant regulation improvements. Near free-ripple charging current for batteries charging is achieved in different states of charge without using burst mode operation, effectively increasing the battery life cycle. In addition, soft transitions are obtained for all the switches (MOSFETs and diodes) resulting in high efficiency, reliability, power density, and low-noise operation of the charger. A complete set of simulation and experimental results, extracted from a 96-VDC 950-W $L3C2$ resonant converter, demonstrates the characteristic features of the proposed topology for battery charger applications, while providing a comparative example with the ${bm LLC}$ topology.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Impedance Matching in Photovoltaic Systems Using Cascaded Boost Converters
           and Sliding-Mode Control
    • Authors: Haroun; R.;Aroudi, A.E.;Cid-Pastor, A.;Garica, G.;Olalla, C.;Martinez-Salamero, L.;
      Pages: 3185 - 3199
      Abstract: Switching dc–dc converters are widely used to interface the dc output of renewable energy resources with power distribution systems in order to facilitate the use of energy at the customer side. In the case of residential photovoltaic (PV) applications, high conversion ratio is usually required, in order to adapt the low output voltages of PV modules to a dc bus voltage, while dealing with the appropriate impedance matching. In this paper, a system connected to a PV panel consisting of two cascaded dc–dc boost converters under sliding-mode control and working as loss-free resistors is studied. The modeling, simulation, and design of the system are addressed. First, an ideal reduced-order sliding-mode dynamics model is derived from the full-order switched model taking into account the sliding constraints, the nonlinear characteristic of the PV module, and the dynamics of the MPPT controller. For this model, a design-oriented averaged model is obtained and its dynamic behavior is analyzed showing that the system is asymptotically globally stable. Moreover, the proposed system can achieve a high conversion ratio with an efficiency close to 95 $%$ for a wide range of working power. Numerical simulations and experimental results corroborate the theoretical analysis and illustrate the advantages of this architecture in PV systems.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Design of Single-Switch Inverters for Variable Resistance/Load
           Modulation Operation
    • Authors: Roslaniec; L.;Jurkov, A.S.;Bastami, A.A.;Perreault, D.J.;
      Pages: 3200 - 3214
      Abstract: Single-Switch inverters such as the conventional Class-E inverter are often highly load sensitive, and maintain zero-voltage switching over only a narrow range of load resistances. This paper introduces a design methodology that enables rapid synthesis of Class E and related single-switch inverters that maintain ZVS operation over a wide range of resistive loads. We treat the design of Class-E inverters for variable resistance operation and show how the proposed methodology relates to circuit transformations on traditional Class-E designs. We also illustrate the use of this transformation approach to realize $Phi _{2}$ inverters for variable-resistance operation. The proposed methodology is demonstrated and experimentally validated at 27.12 MHz in a Class E and $Phi _{2}$ inverter designs that operate efficiently over 12:1 load resistance range for an 8:1 and 10:1 variation in output power, respectively, and a 25-W peak output power.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Multisource and Battery-Free Energy Harvesting Architecture for
           Aeronautics Applications
    • Authors: Vankecke; C.;Assouere, L.;Wang, A.;Durand-Estebe, P.;Caignet, F.;Dilhac, J.;Bafleur, M.;
      Pages: 3215 - 3227
      Abstract: We suggest an innovative architecture for an efficient energy generator devoted to the powering of a wireless sensor network deployed for aircraft health monitoring. This battery-free generator captures energy from its environment (transient thermal gradients as a main source, and vibrations as a secondary source allowing early biasing of the generator) and stores this energy in ultracapacitors. In this way, this multisource architecture benefits from the synergy between energy scavenging and harvesting: vibrations bring low but early and permanent energy. They also contribute to energy harvesting during cruise while thermal gradients have vanished. The use of active diodes and of a very low bias current of 10 nA/branch allow achieving ultralow power consumption, experimentally demonstrated on two different CMOS technologies. It is also proven that enough energy could be delivered to power the functions of a wireless sensor node.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • An Interleaved High-Power Flyback Inverter for Photovoltaic Applications
    • Authors: Tamyurek; B.;Kirimer, B.;
      Pages: 3228 - 3241
      Abstract: This paper presents analysis, design, and implementation of an isolated grid-connected inverter for photovoltaic (PV) applications based on interleaved flyback converter topology operating in discontinuous current mode. In today's PV inverter technology, the simple and the low-cost advantage of the flyback topology is promoted only at very low power as microinverter. Therefore, the primary objective of this study is to design the flyback converter at high power and demonstrate its practicality with good performance as a central-type PV inverter. For this purpose, an inverter system rated at 2 kW is developed by interleaving of only three flyback cells with added benefit of reduced size of passive filtering elements. A simulation model is developed in the piecewise linear electrical circuit simulator. Then, the design is verified and optimized for the best performance based on the simulation results. Finally, a prototype at rated power is built and evaluated under the realistic conditions. The efficiency of the inverter, the total harmonic distortion of the grid current, and the power factor are measured as 90.16%, 4.42%, and 0.998, respectively. Consequently, it is demonstrated that the performance of the proposed system is comparable to the commercial isolated PV inverters in the market, but it may have some cost advantage.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • ${bf+E}^{bf+2}$++Converter+for+Inductive+Links&rft.title=IEEE+Transactions+on+Power+Electronics&rft.issn=0885-8993&rft.date=2015&rft.volume=30&rft.spage=3242&rft.epage=3251&rft.aulast=&rft.aufirst=Luk&rft.au=Luk&rft.au=P.C.;Aldhaher,++S.;Fei,++W.;Whidborne,++J.F.;">State-Space Modeling of a Class        notation="LaTeX">${bf E}^{bf 2}$ Converter
           for Inductive Links
    • Authors: Luk; P.C.;Aldhaher, S.;Fei, W.;Whidborne, J.F.;
      Pages: 3242 - 3251
      Abstract: This paper presents a state-space-based analysis of a Class $hbox{E}^2$ converter for wireless power systems based on a two-coil inductive link. The Class $hbox{E}^2$ converter consists of a 200-kHz Class E inverter as the primary coil driver and a voltage-driven Class E synchronous rectifier at the secondary coil of the inductive link. A piecewise linear seventh-order state-space model is used to calculate several parameters and values to achieve optimum switching operation of the Class E inverter and the Class E rectifier. Simulation results are presented to compare the accuracy of the state-space modeling approach with the established analytical approach. For validation of the state-space analysis, an investigation of the influence of variation of coil alignment and load for a 20-W Class $hbox{E}^2$ converter prototype system is performed by means of a novel compensation method that maintains optimum switching conditions irrespective of variations. Experimental results are presented to confirm the accuracy of the state-space modeling approach over a wide range of operational conditions and the utility of the compensation method.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • A Two-Phase Fully-Integrated DC–DC Converter With Self-Adaptive DCM
           Control and GIPD Passive Components
    • Authors: Chia; C.;Chang, R.C.;Lei, P.;Chen, H.;
      Pages: 3252 - 3261
      Abstract: This paper presents a two-phase fully-integrated dc–dc converter for system-in-package systems with passive components fabricated using a glass-substrate-integrated passive device (GIPD) process. The proposed self-adaptive discontinuous conduction mode (DCM) controller and low-swing/full-swing buffer were incorporated to reduce the switching loss and maintain high efficiency at high switching frequency. A secondary phase and phase controller were added to increase the output power and reduce the output ripple. The proposed GIPD solution packages a standard complementary metal–oxide–semiconductor process and GIPD process in 3-D format to reduce the footprint of the system. The proposed self-adaptive DCM controller and low-swing/full-swing buffer improve efficiency of 15% in measurement compared to our previous work on the GIPD process in simulation. The peak efficiency of the proposed converter was 79.09% at a 400-mA load current, 5% higher than the peak efficiency presented in previous study. The maximal output power could reach 720 mW and the maximal switching frequency ( $f_{{rm CCM}}$ ) was designed to be 70 MHz (measured at 50 MHz) with only two 6-nH inductors and one 15-nF capacitor.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Ultrahigh Step-Down Converter
    • Authors: Hwu; K.I.;Jiang, W.Z.;Yau, Y.T.;
      Pages: 3262 - 3274
      Abstract: In this paper, an ultrahigh step-down converter is presented, which combines one coupled inductor and one energy-transferring capacitor. The corresponding voltage conversion ratio is much lower than that of the traditional synchronously rectified (SR) buck converter, and the proposed converter can achieve extremely low output voltage with an appropriate duty ratio. Moreover, there are three major merits in the proposed converter. One merit is that the voltage conversion ratio of the proposed converter is linear, thereby making control quite easy. Another merit is that if one of the switches fails or is abnormally controlled, a high voltage does not appear in the output terminal, so the output load can be protected. The other merit is that the proposed converter can be driven using the existing SR buck pulse-width modulation control integrated circuit. In this study, brief theoretical deductions and some experimental results are given to verify the feasibility and effectiveness of the proposed converter.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Sensorless Drive for High-Speed Brushless DC Motor Based on the Virtual
           Neutral Voltage
    • Authors: Cui; C.;Liu, G.;Wang, K.;Song, X.;
      Pages: 3275 - 3285
      Abstract: The brushless dc (BLDC) motor can be driven by either pulse-width modulation (PWM) or pulse-amplitude modulation (PAM) techniques. Unfortunately, neither of them can be the most suitable method for the high-speed BLDC motor in the wide speed range, so a hybrid drive method combining PWM and PAM is first introduced. Then, this paper proposes a new sensorless control method based on the virtual neutral voltage for high-speed BLDC motor to suit for this hybrid drive method. In order to obtain the commutation signals from this seriously unclear voltage signal due to the commutation notches and electromagnetic interference, a low-pass filter with super low cutoff frequency is employed at the price of a large phase delay. Meanwhile, a novel sensorless control method based on the transition between “90–α” and “150–α” is introduced to handle the severe phase delay. At last, the feasibility and effectiveness of the proposed drive method and the sensorless control method are verified by several experiment results.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Hybrid Modulation of Dual Inverter for Open-End Permanent Magnet
           Synchronous Motor
    • Authors: Lee; Y.;Ha, J.;
      Pages: 3286 - 3299
      Abstract: This paper analyzes the dual inverter driven open-end permanent magnet synchronous motor (PMSM) system and proposes control method which can generate maximum output power in overall speed range for integrated starter/alternator. Dual inverter driven open-end machine system consists of two inverters which are connected to the both ends of the machine winding. By disconnecting one inverter from the power source, the dc-link voltage of flying capacitor can be boosted through the machine. Because one inverter is connected to the only power source, output power of the machine is regulated by the source connected inverter. In this paper, modulation method for maximizing output power of inverter and motor with reduced harmonic and loss is proposed. It is a hybrid modulation combining six-step and pulse width modulations. With proposed method, efficiency and operation area are improved and cost of entire driving system is also decreased due to the removing of dc–dc converter. Analyses, strategies, control method, and simulation results are descripted. The experiments with PMSM are accomplished to verify the feasibility of proposed method.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • 3-D Thermal Component Model for Electrothermal Analysis of Multichip Power
           Modules With Experimental Validation
    • Authors: Reichl; J.;Ortiz-Rodriguez, J.M.;Hefner, A.;Lai, J.;
      Pages: 3300 - 3308
      Abstract: This paper presents for the first time a full three-dimensional (3-D), multilayer, and multichip thermal component model, based on finite differences, with asymmetrical power distributions for dynamic electrothermal simulation. Finite difference methods (FDMs) are used to solve the heat conduction equation in three dimensions. The thermal component model is parameterized in terms of structural and material properties so it can be readily used to develop a library of component models for any available power module. The FDM model is validated with a full analytical Fourier series-based model in two dimensions. Finally, the FDM thermal model is compared against measured data acquired from a newly developed high-speed transient coupling measurement technique. By using the device threshold voltage as a time-dependent temperature-sensitive parameter (TSP), the thermal transient of a single device, along with the thermal coupling effect among nearby devices sharing common direct bond copper (DBC) substrates, can be studied under a variety of pulsed power conditions.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Predictive Torque Control Scheme for Three-Phase Four-Switch Inverter-Fed
           Induction Motor Drives With DC-Link Voltages Offset Suppression
    • Authors: Zhou; D.;Zhao, J.;liu, y.;
      Pages: 3309 - 3318
      Abstract: The four-switch three-phase (B4) inverter, having a lower number of switches, was first presented for the possibility of reducing the inverter cost, and it became very attractive as it can be utilized in fault-tolerant control to solve the open/short-circuit fault of the six-switch three-phase (B6) inverter. However, the balance among the phase currents collapses due to the fluctuation of the two dc-link capacitor voltages; therefore, its application is limited. This paper proposes a predictive torque control (PTC) scheme for the B4 inverter-fed induction motor (IM) with the dc-link voltage offset suppression. The voltage vectors of the B4 inverter under the fluctuation of the two dc-link capacitor voltages are derived for precise prediction and control of the torque and stator flux. The three-phase currents are forced to stay balance by directly controlling the stator flux. The voltage offset of the two dc-link capacitors is modeled and controlled in the predictive point of view. A lot of simulation and experimental results are presented to validate the proposed control scheme.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Design of a 300-W Isolated Power Supply for Ultrafast Tracking Converters
    • Authors: Nguyen-Duy; K.;Ouyang, Z.;Petersen, L.P.;Knott, A.;Thomsen, O.C.;Andersen, M.A.E.;
      Pages: 3319 - 3333
      Abstract: This paper presents the design of a medium-power-rating isolated power supply for ultrafast tracking converters and MOS-gate driver circuits in medium- and high-voltage applications. The key feature of the design is its very low circuit input-to-output parasitic capacitance, which maximizes its immunity from noise due to fast changes in voltage. The converter is a voltage-controlled current source, utilizing a transformer with extremely low interwinding parasitic capacitance, which is achieved by separating the windings by a significant distance. Experimental measurements show that an overall circuit input-to-output parasitic capacitance of 10 pF in a 300-W prototype can be achieved. The circuit input-to-output capacitance per watt is therefore 30 times lower than that of existing approaches. A mathematical model of the interwinding capacitance of the proposed transformer, circuit analysis, and experimental results are provided to prove the feasibility of the converter.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Analysis and Modeling of High-Power Phosphor-Coated White Light-Emitting
           Diodes With a Large Surface Area
    • Authors: Chen; H.T.;Tan, S.;Hui, S.R.;
      Pages: 3334 - 3344
      Abstract: Modern high-power white light-emitting diodes (LEDs) composed of multiple blue LED chips and yellow phosphor coatings have been successfully commercialized because of their high-luminous efficacy. The multiple-chip LED packages usually come with flat structures that have large surface areas for considerable heat loss. Starting from the analysis and modeling of the blue LED chip, this paper introduces the thermal path through the phosphor layer to form the white phosphor-coated (PC) white LED device model for photometric, electric, and thermal performance analysis. The power distribution of the blue LED chip and that of the PC white LED device are compared. Based on this new analysis, the increase in the heat dissipation coefficient, equivalent thermal resistance, and power loss caused by the phosphor coating can be quantified. New equations suitable for device manufacturers to qualify their devices and design engineers to optimize LED system designs are derived. The analytical results are in good agreement with the practical mesurements.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • $_{bf+DS}$ /dt+and+Temperature&rft.title=IEEE+Transactions+on+Power+Electronics&rft.issn=0885-8993&rft.date=2015&rft.volume=30&rft.spage=3345&rft.epage=3355&rft.aulast=&rft.aufirst=Jahdi&rft.au=Jahdi&rft.au=S.;Alatise,++O.;Ran,++L.;Mawby,++P.;">Analytical Modeling of Switching Energy of Silicon Carbide Schottky Diodes
           as Functions of dI        notation="LaTeX">$_{bf DS}$ /dt and
           Temperature
    • Authors: Jahdi; S.;Alatise, O.;Ran, L.;Mawby, P.;
      Pages: 3345 - 3355
      Abstract: SiC Schottky Barrier diodes (SiC SBD) are known to oscillate/ring in the output terminal when used as free-wheeling diodes in voltage-source converters. This ringing is due to RLC resonance among the diode capacitance, parasitic resistance, and circuit stray inductance. In this paper, a model has been developed for calculating the switching energy of SiC diodes as a function of the switching rate (dI $_{rm DS}/dt$ of the commutating SiC mosfet) and temperature. It is shown that the damping of the oscillations increases with decreasing temperature and decreasing dI $_{rm DS}/dt$ . This in turn determines the switching energy of the diode, which initially decreases with decreasing dI $_{rm DS}/dt$ and subsequently increases with decreasing dI $_{rm DS}/dt$ thereby indicating an optimal dI $_{rm DS}/dt$ for minimum switching energy. The total switching energy of the diode can be subdivided into three phases namely the current switching phase, the voltage switching phase, and the ringing phase. Although the switching energy in the current switching phase decreases with increasing switching rate, the switching energy of the voltage and ringing phase increases with the switching rate. The model developed characterizes the dependence of diode's switching energy on temperature and dI $_{rm DS}/dt$ , hence, can be used to predict the behavior of the SiC SBD.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • DC–DC Converters Dynamic Modeling With State Observer-Based
           Parameter Estimation
    • Authors: Renaudineau; H.;Martin, J.;Nahid-Mobarakeh, B.;Pierfederici, S.;
      Pages: 3356 - 3363
      Abstract: Online knowledge of dc–dc converters behavior is always of great interest. Based on a reliable model of the converters, some great improvement can be achieved. First, the control of the converters can be designed more precisely, especially while thinking in nonlinear theories model-based controls, and it can help to improve the energy management and the efficiency. Also, the knowledge of the converters gives some really useful indications about their state of health and, then, represents a good diagnosis tool and fault detection possibility. This paper proposes a modeling of the converters and a new state observer dedicated to an online estimation of the model parameters. The proposed average models include parameter modeling the losses and their estimation. They are validated on two different converters: the classical dc–dc boost converter and the current-fed dual-bridge dc–dc converter (CFDB—also called isolated boost). It is shown that the model of this last converter is strongly nonlinear, which impacts on the estimation. Simulations and experimental validation are given both on the boost and the isolated boost, and comparisons with the Luenberger state observer and extended Kalman filter are given to underline the interest of the proposed parameter estimation in terms of convergence for nonlinear systems and convergence rapidity.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Distortion-Free Saturators for Power Converters Under Unbalanced
           Conditions
    • Authors: Rizo; M.;Liserre, M.;Bueno, E.J.;Rodriguez, F.J.;Rodriguez, A.;
      Pages: 3364 - 3375
      Abstract: Voltage controlled voltage source converters (VCVSC) and current controlled voltage source converters (CCVSC) have gained importance within distributed power generation systems and equipment for power quality improvement. The control action is susceptible to fall in saturation under disturbance transients or in case of poor control tuning. The use of existing saturation techniques for vector variables, such as three-phase voltage and current, distorts the reference waveforms under unbalanced conditions regardless the used reference frames-–stationary (αβ-axis) or synchronous (dq-axis). These harmonics are quite detrimental for the electric grid and reduce the efficiency. This paper presents a distortion-free saturation methodology with two versions and analyzes the performance in function of the control structure (VCVSC and CCVSC) and the saturation point within the control loop. The experimental results prove the advantages of using the proposed saturators.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Hardware-Efficient Programmable-Deviation Controller for Indirect Energy
           Transfer DC–DC Converters
    • Authors: Peretz; M.M.;Mahdavikhah, B.;Prodic, A.;
      Pages: 3376 - 3388
      Abstract: In boost converters and other indirect energy transfer topologies, the fastest transient response usually does not coincide with the minimum possible output voltage deviation. This paper introduces a practical mixed-signal current programmed mode (CPM) controller that, compared to time-optimal solutions, provides a smaller deviation, lower current stress, and simpler controller implementation. To recover from transients, the controller passes through two phases. In the first phase, the inductor current is set in the proximity of its steady-state value, so that the initial transient-caused capacitor charging/discharging process is reversed. In the second phase, the voltage is gradually recovered. The controller implements a simple algorithm for setting up the inductor current and the output voltage peak/valley values during transients, based on the output current estimate, which is obtained through a self-tuning procedure. The operation of the controller is verified both through simulations and experimentally, with a boost-based 12 to 48 V, 100-W prototype, operating at 100-kHz switching frequency. A comparison with a time-optimal controller shows that the introduced programmable-deviation system results in up to 1.9 times smaller voltage deviation while limiting component stress.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • An Enhanced Islanding Microgrid Reactive Power, Imbalance Power, and
           Harmonic Power Sharing Scheme
    • Authors: He; J.;Li, Y.W.;Blaabjerg, F.;
      Pages: 3389 - 3401
      Abstract: To address inaccurate power sharing problems in autonomous islanding microgrids, an enhanced droop control method through online virtual impedance adjustment is proposed. First, a term associated with DG reactive power, imbalance power, or harmonic power is added to the conventional real power-frequency droop control. The transient real power variations caused by this term are captured to realize DG series virtual impedance tuning. With the regulation of DG virtual impedance at fundamental positive sequence, fundamental negative sequence, and harmonic frequencies, an accurate power sharing can be realized at the steady state. In order to activate the compensation scheme in multiple DG units in a synchronized manner, a low-bandwidth communication bus is adopted to send the compensation command from a microgrid central controller to DG unit local controllers, without involving any information from DG unit local controllers. The feasibility of the proposed method is verified by simulated and experimental results from a low-power three-phase microgrid prototype.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • ${bm+i}/$ d+ ${bm+t}$ +and+d+${bm+v}/$ d ${bm+t}$+ +IGBT+Gate+Driver&rft.title=IEEE+Transactions+on+Power+Electronics&rft.issn=0885-8993&rft.date=2015&rft.volume=30&rft.spage=3402&rft.epage=3417&rft.aulast=&rft.aufirst=Lobsiger&rft.au=Lobsiger&rft.au=Y.;Kolar,++J.W.;">Closed-Loop d ${bm
           i}/$
    d        notation="LaTeX">${bm t}$ and
           d ${bm
           v}/$
    d        notation="LaTeX">${bm t}$ IGBT Gate Driver
    • Authors: Lobsiger; Y.;Kolar, J.W.;
      Pages: 3402 - 3417
      Abstract: This paper proposes a new concept for attaining a defined switching behavior of insulated-gate bipolar transistors (IGBTs) at inductive load (hard) switching, which is a key prerequisite for optimizing the switching behavior in terms of switching losses and electromagnetic interference (EMI). First, state-of-the-art gate driver concepts that enable a control of the IGBT's switching transients are reviewed. Thereafter, a highly dynamic closed-loop IGBT gate driver using simple passive ${rm d}i_{rm C}/{rm d}t$ and ${rm d}v_{rm CE}/{rm d}t$ feedbacks and employing a single analog PI-controller is proposed. Contrary to conventional passive gate drivers, this concept enables an individual control of the current and voltage slopes largely independent of the specific parameters or nonlinearities of the IGBT. Accordingly, a means for optimizing the tradeoff between switching losses, switching delay times, reverse recovery current of the freewheeling diode, turn-off overvoltage, and EMI is gained. The operating principle of the new gate driver is described and based on derived control oriented models of the IGBT, a stability analysis of the closed-loop control is carried out for different IGBT modules. Finally, the proposed concept is experimentally verified for different IGBT modules and compared to a conventional resistive gate driver.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Hysteretic Transition Method for Avoiding the Dead-Zone Effect and
           Subharmonics in a Noninverting Buck–Boost Converter
    • Authors: Restrepo; C.;Konjedic, T.;Calvente, J.;Giral, R.;
      Pages: 3418 - 3430
      Abstract: A new hysteresis window method is proposed as a solution for avoiding the operational dead zone that exists at the transition between buck and boost operating modes in all noninverting buck–boost converters. In addition, this method also eliminates the discontinuities in the converter's steady-state output voltage transfer characteristic, which is a function of the duty cycle. The converter's output voltage function is surjective and, therefore, smooth mode transitions are achieved. The negative effects of operating within the dead zone are shown by the presence of subharmonics in the output voltage, increased output voltage ripple, poor regulation, and the instability of the converter during the transition between buck and boost operating modes. The dead-zone avoidance technique proposed in this paper eliminates all these issues while at the same time ensures highly efficient operation of the converter. An additional advantage of the technique is its simplicity, which allows for implementation into low-cost digital signal controllers, as well as into analog control circuits. The advantageous features of the proposed approach were evaluated on the basis of comparisons with three other dead-zone avoidance approaches and the initial case, which does not utilize any dead-zone avoidance technique. All the experiments were carried out on a purpose-built prototype of a noninverting buck–boost converter with magnetically coupled inductors.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Time-Varying Compensation for Peak Current-Controlled PFC Boost Converter
    • Authors: Cheng; W.;Song, J.;Li, H.;Guo, Y.;
      Pages: 3431 - 3437
      Abstract: In this paper, an optimal time-varying compensation method with zero eigenvalue is first put forward for peak current-controlled power factor correction (PFC) boost converter, which can eliminate the fast-scale instability without zero current dead zone and achieve unity power factor. First, a time-varying mathematic model of a peak current-controlled PFC boost converter under continuous conduction mode is established. Then, based on the theoretical and experimental analyses of the traditional ramp compensation, a time-varying dynamic compensation model and method are presented to obtain zero eigenvalue during the whole line cycle. Therefore, the PFC boost converter occupies the strongest stability control during each switching cycle and can run into stable operation in one switching cycle under any external interference. Finally, the proposed compensation method is verified with experiments. Results show that a unity power factor and the stability in the whole line cycle can be obtained simultaneously.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • Position Offset-Based Parameter Estimation for Permanent Magnet
           Synchronous Machines Under Variable Speed Control
    • Authors: Liu; K.;Zhu, Z.Q.;
      Pages: 3438 - 3446
      Abstract: A position offset-based multiparameter estimation for permanent magnet synchronous machines (PMSMs) under variable speed control is proposed in this paper, which does not need the aid from nominal parameter values of the PMSM and could estimate the rotor permanent magnet (PM) flux linkage and winding resistance separately. For the estimation of rotor PM flux linkage, two sets of PMSM data corresponding to two position offsets are measured while the dq -axis reference currents are set to constants so as to ensure that the estimated machine parameters will not vary during the data measurement. Afterwards, the winding resistance will be estimated from measured PMSM data without addition of position offsets, in which the estimation and compensation of distorted voltage due to inverter nonlinearity are also taken into account. The conventional quantum genetic algorithm is used for aiding the calculation of proposed estimation, which is finally tested on an interior PMSM and shows very good performance in the estimation of rotor PM flux linkage and winding resistance. Thus, it could be used for the condition monitoring of stator winding and rotor PMs of PMSMs.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
  • A Digitally Controlled Critical Mode Boost Power Factor Corrector With
           Optimized Additional On Time and Reduced Circulating Losses
    • Authors: Kim; J.;Youn, H.;Moon, G.;
      Pages: 3447 - 3456
      Abstract: In many low-to-mid power applications, critical mode boost power factor corrector converters are widely used because of its low switching loss and simple control. However, near the zero crossing of the input line voltage, an input current distortion and a low power factor are caused by delayed switching period and negative input currents. Generally, an additional on-time method according to the input voltage is used to compensate the input current distortion. However, a detailed quantitative analysis for the exact additional on time has not been studied till now. In this paper, the explicit form of the optimized additional on time has been obtained using a quantitative analysis and the advantage of the digital control. From a state trajectory and “net input charge” analysis, it is shown that the optimized on time should be related to not only the input voltage, but also the output power. Also, in order to improve the efficiency in a high input and light load condition, circulating currents are reduced in the inevitable dead angle with a gate turning-off technique. By using digital control, the optimized additional on time and the gate turn-off technique have been implemented with the 90–230 Vrms input and 380 V/200 W output prototype.
      PubDate: June 2015
      Issue No: Vol. 30, No. 6 (2015)
       
 
 
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