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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Power Electronics
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Journal DOI :
The Korean Institute of Power Electronics
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Volume & Issues
Volume 13, Issue 6 - Nov 2013
Volume 13, Issue 5 - Sep 2013
Volume 13, Issue 4 - Jul 2013
Volume 13, Issue 3 - May 2013
Volume 13, Issue 2 - Mar 2013
Volume 13, Issue 1 - Jan 2013
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Isolated Boost Converter with Bidirectional Operation for Supercapacitor Applications
Hernandez, Juan C. ; Mira, Maria C. ; Sen, Gokhan ; Thomsen, Ole C. ; Andersen, Michael A.E. ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 507~515
DOI : 10.6113/JPE.2013.13.4.507
This paper presents an isolated bidirectional dc/dc converter based on primary parallel isolated boost converter (PPIBC). This topology is an efficient solution in low voltage high power applications due to its ability to handle high currents in the low voltage side. In this paper, the converter has been modeled using non-ideal components and operated without any additional circuitry for startup using a digital soft-start procedure. Simulated and measured loop gains have been compared for the validity of the model. On-the-fly current direction change has been achieved with a prototype interconnecting two battery banks. A second prototype has been constructed and tested for supercapacitor operation in constant power charge mode.
Adaptive On-line State-of-available-power Prediction of Lithium-ion Batteries
Fleischer, Christian ; Waag, Wladislaw ; Bai, Ziou ; Sauer, Dirk Uwe ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 516~527
DOI : 10.6113/JPE.2013.13.4.516
This paper presents a new overall system for state-of-available-power (SoAP) prediction for a lithium-ion battery pack. The essential part of this method is based on an adaptive network architecture which utilizes both fuzzy model (FIS) and artificial neural network (ANN) into the framework of adaptive neuro-fuzzy inference system (ANFIS). While battery aging proceeds, the system is capable of delivering accurate power prediction not only for room temperature, but also at lower temperatures at which power prediction is most challenging. Due to design property of ANN, the network parameters are adapted on-line to the current battery states (state-of-charge (SoC), state-of-health (SoH), temperature). SoC is required as an input parameter to SoAP module and high accuracy is crucial for a reliable on-line adaptation. Therefore, a reasonable way to determine the battery state variables is proposed applying a combination of several partly different algorithms. Among other SoC boundary estimation methods, robust extended Kalman filter (REKF) for recalibration of amp hour counters was implemented. ANFIS then achieves the SoAP estimation by means of time forward voltage prognosis (TFVP) before a power pulse occurs. The trade-off between computational cost of batch-learning and accuracy during on-line adaptation was optimized resulting in a real-time system with TFVP absolute error less than 1%. The verification was performed on a software-in-the-loop test bench setup using a 53 Ah lithium-ion cell.
Traction Motor-Inverter Utilized Battery Charger for PHEVs
Woo, Dong-Gyun ; Kim, Yun-Sung ; Kang, Gu-Bae ; Lee, Byoung-Kuk ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 528~535
DOI : 10.6113/JPE.2013.13.4.528
Most eco-friendly cars can adopt the concept of an integrated battery charger (IBC), which uses currently available motor drive systems. The IBC has a lot of strong points such as low cost and minimum space for the high voltage battery charger. On the other hand, it also has some defects caused by its structure. In this paper, the shortcomings of the conventional IBC for PHEVs with interior permanent magnet motors are discussed, and two advanced IBCs with improved performance are presented. Compared with the conventional IBC, the two advanced IBCs have plenty of strengths such as low common noise, high efficiency, simple sensing methods, etc. Then, the digital control algorithm is modified and a power loss calculation is carried out with simulation software. Finally, experimental results are provided to show the performance of the IBC systems.
A Study on In-wheel Motor Control to Improve Vehicle Stability Using Human-in-the-Loop Simulation
Ko, Sung-Yeon ; Ko, Ji-Weon ; Lee, Sang-Moon ; Cheon, Jae-Seung ; Kim, Hyun-Soo ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 536~545
DOI : 10.6113/JPE.2013.13.4.536
In this study, an integrated motor control algorithm for an in-wheel electric vehicle is suggested. It consists of slip control that controls the in-wheel motor torque using the road friction coefficient and slip ratio; yaw rate control that controls the in-wheel motor torque according to the road friction coefficient and the yaw rate error; and velocity control that controls the vehicle velocity by a weight factor based on the road friction coefficient and the yaw rate error. A co-simulator was developed, which combined the vehicle performance simulator based on MATLAB/Simulink and the vehicle model of CarSim. Based on the co-simulator, a human-in-the-loop simulation environment was constructed, in which a driver can directly control the steering wheel, the accelerator pedal, and the brake pedal in real time. The performance of the integrated motor control algorithm for the in-wheel electric vehicle was evaluated through human-in-the-loop simulations.
Optimum Design of Stator and Rotor Shape for Cogging Torque Reduction in Interior Permanent Magnet Synchronous Motors
Yu, Ju-Seong ; Cho, Han-Wook ; Choi, Jang-Young ; Jang, Seok-Myeong ; Lee, Sung-Ho ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 546~551
DOI : 10.6113/JPE.2013.13.4.546
This paper deals with the optimum design of the stator and rotor shape of the interior permanent magnet synchronous motors (IPMSM) that are used in applications for automobiles. IPMSMs have the following advantages: high power, high torque, high efficiency, etc. However, cogging torque which causes noise and vibrations is generated at the same time. The optimum design of shape of a IPMSM was carried out with the aim of reducing cogging torque. Six variables which affect to the performance of a IPMSM are chosen. The main effect variables were determined and applied to the response surface methodology (RSM). When compared to the initial model using the finite elements method (FEM), the optimum model highly reduces the cogging torque and improves the total harmonics distortion (THD) of the back-electro motive force (EMF). A prototype of the designed model was manufactured and experimented on to verify the feasibility of the IPMSM.
Calculation of Distributed Magnetic Flux Density under the Stator-Turn Fault Condition
Kim, Kyung-Tae ; Hur, Jin ; Kim, Byeong-Woo ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 552~557
DOI : 10.6113/JPE.2013.13.4.552
This paper proposed an analytical model for the distributed magnetic field analysis of interior permanent magnet-type blush-less direct current motors under the stator-turn fault condition using the winding function theory. Stator-turn faults cause significant changes in electric and magnetic characteristic. Therefore, many studies on stator-turn faults have been performed by simulation of the finite element method because of its non-linear characteristic. However, this is difficult to apply to on-line fault detection systems because the processing time of the finite element method is very long. Fault-tolerant control systems require diagnostic methods that have simple processing systems and can produce accurate information. Thus analytical modeling of a stator-turn fault has been performed using the winding function theory, and the distributed magnetic characteristics have been analyzed under the fault condition. The proposed analytical model was verified using the finite element method.
Analysis and Design of a Three-port Flyback Inverter using an Active Power Decoupling Method to Minimize Input Capacitance
Kim, Jun-Gu ; Kim, Kyu-Dong ; Noh, Yong-Su ; Jung, Yong-Chae ; Won, Chung-Yuen ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 558~568
DOI : 10.6113/JPE.2013.13.4.558
In this paper, a new decoupling technique for a flyback inverter using an active power decoupling circuit with auxiliary winding and a novel switching pattern is proposed. The conventional passive power decoupling method is applied to control Maximum Power Point Tracking (MPPT) efficiently by attenuating double frequency power pulsation on the photovoltaic (PV) side. In this case, decoupling capacitor for a flyback inverter is essentially required large electrolytic capacitor of milli-farads. However using the electrolytic capacitor have problems of bulky size and short life-span. Because this electrolytic capacitor is strongly concerned with the life-span of an AC module system, an active power decoupling circuit to minimize input capacitance is needed. In the proposed topology, auxiliary winding defined as a Ripple port will partially cover difference between a PV power and an AC Power. Since input capacitor and auxiliary capacitor is reduced by Ripple port, it can be replaced by a film capacitor. To perform the operation of charging/discharging decoupling capacitor
, a novel switching sequence is also proposed. The proposed topology is verified by design analysis, simulation and experimental results.
On Thermal and State-of-Charge Balancing using Cascaded Multi-level Converters
Altaf, Faisal ; Johannesson, Lars ; Egardt, Bo ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 569~583
DOI : 10.6113/JPE.2013.13.4.569
In this study, the simultaneous use of a multi-level converter (MLC) as a DC-motor drive and as an active battery cell balancer is investigated. MLCs allow each battery cell in a battery pack to be independently switched on and off, thereby enabling the potential non-uniform use of battery cells. By exploiting this property and the brake regeneration phases in the drive cycle, MLCs can balance both the state of charge (SoC) and temperature differences between cells, which are two known causes of battery wear, even without reciprocating the coolant flow inside the pack. The optimal control policy (OP) that considers both battery pack temperature and SoC dynamics is studied in detail based on the assumption that information on the state of each cell, the schedule of reciprocating air flow and the future driving profile are perfectly known. Results show that OP provides significant reductions in temperature and in SoC deviations compared with the uniform use of all cells even with uni-directional coolant flow. Thus, reciprocating coolant flow is a redundant function for a MLC-based cell balancer. A specific contribution of this paper is the derivation of a state-space electro-thermal model of a battery submodule for both uni-directional and reciprocating coolant flows under the switching action of MLC, resulting in OP being derived by the solution of a convex optimization problem.
6.6 kW On-Vehicle Charger with a Hybrid Si IGBTs and SiC SBDs Based Booster Power Module
Han, Timothy Junghee ; Preston, Jared ; Ouwerkerk, David ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 584~591
DOI : 10.6113/JPE.2013.13.4.584
In this paper, a hybrid booster power module with Si IGBT and Silicon Carbide (SiC) Schottky Barrier Diode (SBDs) is presented. The switching characteristics of the hybrid booster module are compared with commercial Silicon IGBT/Si PIN diode based modules. We applied the booster power module into a non-isolated on board vehicle charger with a simple buck-booster topology. The performances of the on-vehicle charger are analyzed and measured with different power modules. The test data is measured in the same system, at the same points of operation, using the conventional Si and hybrid Si/SiC power modules. The measured power conversion efficiency of the proposed on-vehicle charger is 96.4 % with the SiC SBD based hybrid booster module. The conversion efficiency gain of 1.4 % is realizable by replacing the Si-based booster module with the Si IGBT/SiC SBD hybrid boost module in the 6.6 kW on-vehicle chargers.
New Isolated Single-Phase AC-DC Converter for Universal Input Voltage
Lee, Ming-Rong ; Yang, Lung-Sheng ; Lin, Chia-Ching ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 592~599
DOI : 10.6113/JPE.2013.13.4.592
This paper investigates a new isolated single-phase AC-DC converter, which integrates a modified AC-DC buck-boost converter with a DC-DC forward converter. The front semi-stage is operated in discontinuous conduction mode (DCM) to achieve an almost unity power factor and a low total harmonic distortion of the input current. The rear semi-stage is used for step-down voltage conversion and electrical isolation. The front semi-stage uses a coupled inductor with the same winding-turn in the primary and secondary sides, which is charged in series during the switch-on period and is discharged in parallel during the switch-off period. The discharging time can be shortened. In other words, the duty ratio can be extended. This semi-stage can be operated in a larger duty-ratio range than the conventional AC-DC buck-boost converter for DCM operation. Therefore, the proposed converter is suitable for universal input voltage (90~264
) and a wide output-power range. Moreover, the voltage stress on the DC-link capacitor is low. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.
Analysis of the Admittance Component for Digitally Controlled Single-Phase Bridgeless PFC Converter
Cho, Younghoon ; Mok, Hyungsoo ; Lai, Jih-Sheng ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 600~608
DOI : 10.6113/JPE.2013.13.4.600
This paper analyzes the effect of the admittance component for the digitally controlled single-phase bridgeless power factor correction (PFC) converter. To do this, it is shown how the digital delay effects such as the digital pulse-width modulation (DPWM) and the computation delays restrict the bandwidth of the converter. After that, the admittance effect of the entire digital control system is analyzed when the bridgeless PFC converter which has the limited bandwidth is connected to the grid. From this, the waveform distortion of the input current is explained and the compensation method for the admittance component is suggested to improve the quality of the input current. Both the simulations and the experiments are performed to verify the analyses taken in this paper for the 1 kW bridgeless PFC converter prototype.
Primary Side Constant Power Control Scheme for LED Drivers Compatible with TRIAC Dimmers
Zhang, Junming ; Jiang, Ting ; Xu, Lianghui ; Wu, Xinke ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 609~618
DOI : 10.6113/JPE.2013.13.4.609
This paper proposes a primary side constant power control scheme for TRIAC dimmer compatible LED drivers. The LED driver is a Flyback converter operated in boundary conduction mode (BCM) to minimize the switching loss. With the proposed control scheme, the input power of the Flyback converter can be controlled by the TRIAC dimming angle, which is not affected by AC input voltage variations. Since the output voltage is almost constant for LED loads, the output current can be changed by controlling the input power with a given conversion efficiency. The isolated feedback circuit is eliminated with the proposed primary side control scheme, which dramatically simplifies the whole circuit. In addition, the input current automatically follows the input voltage due to the BCM operation, and the resistive input characteristic can be achieved which is attractive for TRIAC dimming applications. Experimental results from a 15W prototype verify the theoretical analysis.
Experimental Study on Conducted EMI Mitigation in SMPS using a Novel Spread Spectrum Technique
Premalatha, L. ; Raghavendiran, T.A. ; Ravichandran, C. ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 619~625
DOI : 10.6113/JPE.2013.13.4.619
Switched mode power supplies (SMPS) are power electronic circuits extensively used in a wide range of applications. High frequency switching operation of SMPS causes electromagnetic emissions and has the potential to interfere with system operation, which in turn has an impact on system performance. This makes electromagnetic compatibility (EMC) an important concern. In this paper, a new and simple spread spectrum technique is proposed by modulating chaotic pulse position modulation (CPPM) and pulse width modulation (PWM). The resulting CPWM is implemented to reduce the conducted EMI in SMPS. The proposed method is found to be effective in reducing conduction EMI. The effectiveness and simplicity of the proposed method on spreading those dominating frequencies is compared to the EMI mitigation technique using an external chaotic generator. Finally, the levels of conductive EMI with standard PWM, CPWM with an external chaos generator and the proposed method are experimentally verified to comply with the CISPR 22A regulations. The results confirm the effectiveness of the proposed method.
Analysis and Implementation of a Half Bridge Class-DE Rectifier for Front-End ZVS Push-Pull Resonant Converters
Ekkaravarodome, Chainarin ; Jirasereeamornkul, Kamon ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 626~635
DOI : 10.6113/JPE.2013.13.4.626
An analysis of the junction capacitance in resonant rectifiers which has a significant impact on the operating point of resonance circuits is studied in this paper, where the junction capacitance of the rectifier diode is to decrease the resonant current and output voltage in the circuit when compared with that in an ideal rectifier diode. This can be represented by a simplified series resonant equivalent circuit and a voltage transfer function versus the normalized operating frequency at varied values of the resonant capacitor. A low voltage to high voltage push-pull DC/DC resonant converter was used as a design example. The design procedure is based on the principle of the half bridge class-DE resonant rectifier, which ensures more accurate results. The proposed scheme provides a more systematic and feasible solution than the conventional resonant push-pull DC/DC converter analysis methodology. To increase circuit efficiency, the main switches and the rectifier diodes can be operated under the zero-voltage and zero-current switching conditions, respectively. In order to achieve this objective, the parameters of the DC/DC converter need to be designed properly. The details of the analysis and design of this DC/DC converter`s components are described. A prototype was constructed with a 62-88 kHz variable switching frequency, a 12
input voltage, a 380
output voltage, and a rated output power of 150 W. The validity of this approach was confirmed by simulation and experimental results.
Analysis and Design of a Single-Phase Tapped-Coupled-Inductor Boost DC-DC Converter
Gitau, Michael Njoroge ; Mwaniki, Fredrick Mukundi ; Hofsajer, Ivan W. ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 636~646
DOI : 10.6113/JPE.2013.13.4.636
A single-phase tapped-inductor boost converter has been proposed previously. However, detailed characterization and performance analysis were not conducted. This paper presents a detailed characterization, performance analysis, and design expressions of a single-phase tapped-coupled-inductor boost converter. Expressions are derived for average and RMS input current as well as for RMS input and output capacitor current ripple. A systematic approach for sizing the tapped-coupled inductor, active switch, and output diode is presented; such approach has not been reported in related literature. This study reveals that sizing of the inductor has to be based on current ripple requirement, turns ratio, and load. Conditions that produce discontinuous inductor current are also discussed. Analysis of a non-ideal converter operating in continuous conduction mode is also conducted. The expression for the voltage ratio considering the coupling coefficient is derived. The suitability of the converter for high-voltage step-up applications is evaluated. Factors that affect the voltage boost ratio are also identified. The effects of duty ratio and load variation on the performance of the converter are also investigated. The theoretically derived characteristics are validated through simulations. Experimental results obtained at a low power level are included to validate the analytical and simulation results. A good agreement is observed among the analytical, simulation, and experimental results.
Improved Space Vector Modulation Strategy for AC-DC Matrix Converters
Liu, Xiao ; Zhang, Qingfan ; Hou, Dianli ; Wang, Siyao ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 647~655
DOI : 10.6113/JPE.2013.13.4.647
In this paper, an approach to reduce the common-mode voltage and to eliminate narrow pulse for implemented AC-DC matrix converters is presented. An improved space vector modulation (SVM) strategy is developed by replacing the zero space vectors with suitable pairs of active ones. Further, while considering the commutation time, the probability of narrow pulse in the conventional and proposed SVM methods are derived and compared. The advantages of the proposed scheme include: a 50% reduction in the peak value of the common-mode voltage; improved input and output performances; a reduction in the switching loss by a reduced number of switching commutations and a simplified implementation via software. Experimental results are presented to demonstrate the correctness of the theoretical analysis, as well as the feasibility of the proposed strategy.
Novel Wavelet-Fuzzy Based Indirect Field Oriented Control of Induction Motor Drives
Febin Daya, J.L. ; Subbiah, V. ; Atif, Iqbal ; Sanjeevikumar, Padmanaban ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 656~668
DOI : 10.6113/JPE.2013.13.4.656
This paper presents a wavelet-fuzzy based controller for indirect field oriented control of three-phase induction motor drives. The discrete wavelet transform is used to decompose the error between the actual speed and the command speed of the induction motor drive into different frequency components. The transformed error coefficients along with the scaling gains are used for generating the control component of the motor. Self-tuning fuzzy logic is used for online tuning of the scaling gains of the controller. The proposed controller has the ability to meet the speed tracking requirements in the closed loop system. The complete indirect field oriented control scheme incorporating the proposed wavelet-fuzzy based controller is investigated theoretically and simulated under various dynamic operating conditions. The simulation results are compared with a conventional proportional integral controller and a fuzzy based controller. The speed control scheme incorporating the proposed controller is implemented in real time using a digital processor control board. Simulation and experimental results validate the effectiveness of the proposed controller.
Sensorless Control of Wound Rotor Synchronous Machines Based on High-frequency Signal Injection into the Stator Windings
Chen, Zhiguo ; Deng, Xianming ; Huang, Kun ; Zhen, Wenhuan ; Wang, Lei ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 669~678
DOI : 10.6113/JPE.2013.13.4.669
This paper proposes a sensorless control approach for Wound Rotor Synchronous Machines (WRSMs) based on a high frequency voltage signal injection into the stator side U phase and VW line, respectively. Considering the machine itself as a rotor position sensor, the rotor position observer is established according to the principles of the rotary transformer. A demodulation method for the high frequency signal inducted in the rotor is proposed as well. Simulation and experimental results show that the proposed sensorless control approach has high performance and good practicability.
Modeling and Control Method for High-power Electromagnetic Transmitter Power Supplies
Yu, Fei ; Zhang, Yi-Ming ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 679~691
DOI : 10.6113/JPE.2013.13.4.679
High-power electromagnetic transmitter power supplies are an important part of deep geophysical exploration equipment. This is especially true in complex environments, where the ability to produce a highly accurate and stable output and safety through redundancy have become the key issues in the design of high-power electromagnetic transmitter power supplies. To solve these issues, a high-frequency switching power cascade based emission power supply is designed. By combining the circuit averaged model and the equivalent controlled source method, a modular mathematical model is established with the on-state loss and transformer induction loss being taken into account. A triple-loop control including an inner current loop, an outer voltage loop and a load current forward feedback, and a digitalized voltage/current sharing control method are proposed for the realization of the rapid, stable and highly accurate output of the system. By using a new algorithm referred to as GAPSO, which integrates a genetic algorithm and a particle swarm algorithm, the parameters of the controller are tuned. A multi-module cascade helps to achieve system redundancy. A simulation analysis of the open-loop system proves the accuracy of the established system and provides a better reflection of the characteristics of the power supply. A parameter tuning simulation proves the effectiveness of the GAPSO algorithm. A closed-loop simulation of the system and field geological exploration experiments demonstrate the effectiveness of the control method. This ensures both the system`s excellent stability and the output`s accuracy. It also ensures the accuracy of the established mathematical model as well as its ability to meet the requirements of practical field deep exploration.
A New Synchronous Reference Frame-Based Method for Single-Phase Shunt Active Power Filters
Monfared, Mohammad ; Golestan, Saeed ; Guerrero, Josep M. ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 692~700
DOI : 10.6113/JPE.2013.13.4.692
This paper discusses the design of a novel synchronous reference frame (SRF) method that can extract the reference compensating current for single-phase shunt active power filters (APFs). Unlike previous SRF studies, the proposed method has an innovative feature that does not require a fictitious current signal. Other key features of the proposed strategy include frequency-independent operation, accurate reference current extraction, and relatively fast transient response. The effectiveness of the proposed method is investigated by conducting a detailed mathematical analysis. Results of the analysis confirm the superior performance of the suggested approach. Theoretical evaluations are confirmed by the experimental results.
Study on the Influence of Distribution Lines to Parallel Inverter Systems Adopting the Droop Control Method
Zhang, Xuan ; Liu, Jinjun ; You, Zhiyuan ; Liu, Ting ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 701~711
DOI : 10.6113/JPE.2013.13.4.701
This paper takes into account the influence of the different impedances of distribution lines on power distribution among inverters when the inverters are paralleled with the droop control method. The impact of distribution lines on the power distribution of inverters can be divided into two aspects. Firstly, since the distributed generators are in low voltage grids, there is resistive impedance in the distribution lines, which will cause control coupling and reduce system stability. The virtual negative resistive impedance of inverters is adopted in this paper to neutralize the resistive element of distribution lines and thus make the distribution line impedance purely inductive. Secondly, after solving the resistive impedance problem, the difference in the inductive impedance value of distribution lines due to the low density of distributed generators will cause an unequal share of reactive power. With regards to this problem, modification is put forward for the droop control strategy to share the reactive power equally. The feasibility of the design is validated by simulation and experimental results.
Control Method for Reducing the THD of Grid Current of Three-Phase Grid-Connected Inverters Under Distorted Grid Voltages
Tran, Thanh-Vu ; Chun, Tae-Won ; Lee, Hong-Hee ; Kim, Heung-Geun ; Nho, Eui-Cheol ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 712~718
DOI : 10.6113/JPE.2013.13.4.712
This paper proposes a control method for reducing the total harmonic distortion (THD) of the grid current of three-phase grid-connected inverter systems when the grid voltage is distorted. The THD of the grid current caused by grid voltage harmonics is derived by considering the phase delay and magnitude attenuation due to the hardware low-pass filter (LPF). The Cauchy-Schwarz inequality theory is used in order to search more easily for the minimum point of the THD. Both the gain and angle of the compensation voltage at the minimum point of the THD of the grid current are derived with the variation of cut-off frequencies of the hardware LPF. Simulation and experimental results show the validity of the proposed control methods.
A Novel Hybrid Active Power Filter with a High-Voltage Rank
Li, Yan ; Li, Gang ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 719~728
DOI : 10.6113/JPE.2013.13.4.719
A novel hybrid active power filter (NHAPF) that can be adopted in high-voltage systems is proposed in this paper. The topological structure and filtering principle of the compensating system is provided and analyzed, respectively. Different controlling strategies are also presented to select the suitable strategy for the compensation system. Based on the selected strategy, the harmonic suppression function is used to analyze the influence of system parameters on the compensating system with MATLAB. Moreover, parameters in the injection branch are designed and analyzed. The performance of the proposed NHAPF in harmonic suppression and reactive power compensation is simulated with PSim. Thereafter, the overall control method is proposed. Simulation analysis and real experiments show that the proposed NHAPF exhibits good harmonic suppression and reactive power compensation. The proposed compensated system is based on the three-phase four-switch inverter, which is inexpensive, and the control method is verified for validity and effectiveness.
Estimation of Insulated-gate Bipolar Transistor Operating Temperature: Simulation and Experiment
Bahun, Ivan ; Sunde, Viktor ; Jakopovic, Zeljko ;
Journal of Power Electronics, volume 13, issue 4, 2013, Pages 729~736
DOI : 10.6113/JPE.2013.13.4.729
Knowledge of a power semiconductor`s operating temperature is important in circuit design and converter control. Designing appropriate circuitry that does not affect regular circuit operation during virtual junction temperature measurement at actual operating conditions is a demanding task for engineers. The proposed method enables virtual junction temperature estimation with a dedicated modified gate driver circuit based on real-time measurement of a semiconductor`s quasi-threshold voltage. A simulation was conducted before the circuit was designed to verify the concept and to determine the basic properties and potential drawbacks of the proposed method.