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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 15, Issue 6 - Nov 2015
Volume 15, Issue 5 - Sep 2015
Volume 15, Issue 4 - Jul 2015
Volume 15, Issue 3 - May 2015
Volume 15, Issue 2 - Mar 2015
Volume 15, Issue 1 - Jan 2015
Selecting the target year
Modified Dual-Buck Inverter Based on Resonant Link
Chen, Rong ; Zhang, Jia-Sheng ; Liu, Wei ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1421~1428
DOI : 10.6113/JPE.2015.15.6.1421
The efficiency and reliability of the dual-buck inverter (DBI) were greatly improved by eliminating the shoot-through problem and optimally designing the freewheeling diode. The traditional DBI suffers from large harmonic components with low output voltage and large capacity output filter inductor. To overcome the aforementioned disadvantages, a modified DBI (MBDI) was proposed by adopting a quasi-resonant link and pulse density modulation (PDM). This paper first introduces the working principle of the MBDI and PDM, and then the selection principle of system parameters is presented. Finally, a mathematical model of the MBDIis built, and an experiment prototype is set up. Simulation and experimental results verify the correctness of the theoretical analysis and the feasibility of the scheme.
A Parallel Hybrid Soft Switching Converter with Low Circulating Current Losses and a Low Current Ripple
Lin, Bor-Ren ; Chen, Jia-Sheng ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1429~1437
DOI : 10.6113/JPE.2015.15.6.1429
A new parallel hybrid soft switching converter with low circulating current losses during the freewheeling state and a low output current ripple is presented in this paper. Two circuit modules are connected in parallel using the interleaved pulse-width modulation scheme to provide more power to the output load and to reduce the output current ripple. Each circuit module includes a three-level converter and a half-bridge converter sharing the same lagging-leg switches. A resonant capacitor is adopted on the primary side of the three-level converter to reduce the circulating current to zero in the freewheeling state. Thus, the high circulating current loss in conventional three-level converters is alleviated. A half-bridge converter is adopted to extend the ZVS range. Therefore, the lagging-leg switches can be turned on under zero voltage switching from light load to full load conditions. The secondary windings of the two converters are connected in series so that the rectified voltage is positive instead of zero during the freewheeling interval. Hence, the output inductance of the three-level converter can be reduced. The circuit configuration, operation principles and circuit characteristics are presented in detail. Experiments based on a 1920W prototype are provided to verify the effectiveness of the proposed converter.
Analysis and Implementation of a DC-DC Converter for Hybrid Power Supplies Systems
Yang, Lung-Sheng ; Lin, Chia-Ching ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1438~1445
DOI : 10.6113/JPE.2015.15.6.1438
A new DC-DC power converter is researched for renewable energy and battery hybrid power supplies systems in this paper. At the charging mode, a renewable energy source provides energy to charge a battery via the proposed converter. The operating principle of the proposed converter is the same as the conventional DC-DC buck converter. At the discharging mode, the battery releases its energy to the DC bus via the proposed converter. The proposed converter is a non-isolated high step-up DC-DC converter. The coupled-inductor technique is used to achieve a high step-up voltage gain by adjusting the turns ratio. Moreover, the leakage-inductor energies of the primary and secondary windings can be recycled. Thus, the conversion efficiency can be improved. Therefore, only one power converter is utilized at the charging or discharging modes. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.
Resonant Tank Design Considerations and Implementation of a LLC Resonant Converter with a Wide Battery Voltage Range
Sun, Wenjin ; Wu, Hongfei ; Hu, Haibing ; Xing, Yan ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1446~1455
DOI : 10.6113/JPE.2015.15.6.1446
This paper illustrates resonant tank design considerations and the implementation of a LLC resonant converter with a wide battery voltage range based on the fundamental harmonic approximation (FHA) analysis. Unlike the conventional design at zero load, the parameter K (the ratio of the transformer magnetizing inductor L
to the resonant inductor L
) of the LLC converter in this paper is designed with two charging points, (V
) and (V
), according to the battery charging strategy. A 2.9kW prototype with an output voltage range of 36V to 72V dc is built to verify the design. It achieves a peak efficiency of 96%.
A Control Strategy Based on Small Signal Model for Three-Phase to Single-Phase Matrix Converters
Chen, Si ; Ge, Hongjuan ; Zhang, Wenbin ; Lu, Song ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1456~1467
DOI : 10.6113/JPE.2015.15.6.1456
This paper presents a novel close-loop control scheme based on small signal modeling and weighted composite voltage feedback for a three-phase input and single-phase output Matrix Converter (3-1MC). A small non-polar capacitor is employed as the decoupling unit. The composite voltage weighted by the load voltage and the decoupling unit voltage is used as the feedback value for the voltage controller. Together with the current loop, the dual-loop control is implemented in the 3-1MC. In this paper, the weighted composite voltage expression is derived based on the sinusoidal pulse-width modulation (SPWM) strategy. The switch functions of the 3-1MC are deduced, and the average signal model and small signal model are built. Furthermore, the stability and dynamic performance of the 3-1MC are studied, and simulation and experiment studies are executed. The results show that the control method is effective and feasible. They also show that the design is reasonable and that the operating performance of the 3-1MC is good.
High Efficiency High-Step-up Single-ended DC-DC Converter with Small Output Voltage Ripple
Kim, Do-Hyun ; Kim, Hyun-Woo ; Park, Joung-Hu ; Jeon, Hee-Jong ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1468~1479
DOI : 10.6113/JPE.2015.15.6.1468
Renewable energy resources such as wind and photovoltaic power generation systems demand a high step-up DC-DC converters to convert the low voltage to commercial grid voltage. However, the high step-up converter using a transformer has limitations of high voltage stresses of switches and diodes when the transformer winding ratio increases. Accordingly, conventional studies have been applied to series-connect multioutput converters such as forward-flyback and switched-capacitor flyback to reduce the transformer winding ratio. This paper proposes new single-ended converter topologies of an isolation type and a non-isolation type to improve power efficiency, cost-effectiveness, and output ripple. The first proposal is an isolation-type charge-pump switched-capacitor flyback converter that includes an extreme-ratio isolation switched-capacitor cell with a chargepump circuit. It reduces the transformer winding number and the output ripple, and further improves power efficiency without any cost increase. The next proposal is a non-isolation charge-pump switched-capacitor-flyback tapped-inductor boost converter, which adds a charge-pump-connected flyback circuit to the conventional switched-capacitor boost converter to improve the power efficiency and to reduce the efficiency degradation from the input variation. In this paper, the operation principle of the proposed scheme is presented with the experimental results of the 100 W DC-DC converter for verification.
A Simple Structure of Zero-Voltage Switching (ZVS) and Zero-Current Switching (ZCS) Buck Converter with Coupled Inductor
Wei, Xinxin ; Luo, Ciyong ; Nan, Hang ; Wang, Yinghao ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1480~1488
DOI : 10.6113/JPE.2015.15.6.1480
In this paper, a revolutionary buck converter is proposed with soft-switching technology, which is realized by a coupled inductor. Both zero-voltage switching (ZVS) of main switch and zero-current switching (ZCS) of freewheeling diode are achieved at turn on and turn off without using any auxiliary circuits by the resonance between the parasitic capacitor and the coupled inductor. Furthermore, the peak voltages of the main switch and the peak current of the freewheeling diode are significantly reduced by the coupled inductor. As a result, the proposed converter has the advantages of simple circuit, convenient control, low consumption and so on. The detailed operation principles and steady-state analysis of the proposed ZVS-ZCS buck converter are presented, and detailed power loss analysis and some simulation results are also included. Finally, experimental results based on a 200-W prototype are provided to verify the theory and design of the proposed converter.
Performance Evaluation of GaN-Based Synchronous Boost Converter under Various Output Voltage, Load Current, and Switching Frequency Operations
Han, Di ; Sarlioglu, Bulent ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1489~1498
DOI : 10.6113/JPE.2015.15.6.1489
Gallium nitride (GaN)-based power switching devices, such as high-electron-mobility transistors (HEMT), provide significant performance improvements in terms of faster switching speed, zero reverse recovery, and lower on-state resistance compared with conventional silicon (Si) metal-oxide-semiconductor field-effect transistors (MOSFET). These benefits of GaN HEMTs further lead to low loss, high switching frequency, and high power density converters. Through simulation and experimentation, this research thoroughly contributes to the understanding of performance characterization including the efficiency, loss distribution, and thermal behavior of a 160-W GaN-based synchronous boost converter under various output voltage, load current, and switching frequency operations, as compared with the state-of-the-art Si technology. Original suggestions on design considerations to optimize the GaN converter performance are also provided.
Control Strategy of MMC-HVDC under Unbalanced Grid Voltage Conditions
Zhang, Jianpo ; Zhao, Chengyong ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1499~1507
DOI : 10.6113/JPE.2015.15.6.1499
High voltage direct current transmission based on modular multilevel converter (MMC-HVDC) is one of the most promising power transmission technologies. In this study, the mathematical characteristics of MMC-HVDC are analyzed in a synchronous rotational reference frame. A hybrid current vector controller based on proportional integer plus resonant is used to uniformly control the DC and double-base frequency AC currents under unbalanced grid voltage conditions. A corresponding voltage dependent current order limiter is then designed to solve the overcurrent problems that may occur. Moreover, the circulating current sequence components are thoroughly examined and controlled using a developed circulating current suppressor. Simulation results verify the correctness and effectiveness of the proposed control schemes.
Cascaded Multi-Level Inverter Based IPT Systems for High Power Applications
Li, Yong ; Mai, Ruikun ; Yang, Mingkai ; He, Zhengyou ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1508~1516
DOI : 10.6113/JPE.2015.15.6.1508
A single phase H-bridge inverter is employed in conventional Inductive Power Transfer (IPT) systems as the primary side power supply. These systems may not be suitable for some high power applications, due to the constraints of the power electronic devices and the cost. A high-frequency cascaded multi-level inverter employed in IPT systems, which is suitable for high power applications, is presented in this paper. The Phase Shift Pulse Width Modulation (PS-PWM) method is proposed to realize power regulation and selective harmonic elimination. Explicit solutions against phase shift angle and pulse width are given according to the constraints of the selective harmonic elimination equation and the required voltage to avoid solving non-linear transcendental equations. The validity of the proposed control approach is verified by the experimental results obtained with a 2kW prototype system. This approach is expected to be useful for high power IPT applications, and the output power of each H-bridge unit is identical by the proposed approach.
Wavelet PWM Technique for Single-Phase Three-Level Inverters
Zheng, Chun-Fang ; Zhang, Bo ; Qiu, Dong-Yuan ; Zhang, Xiao-Hui ; Xiao, Le-Ming ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1517~1523
DOI : 10.6113/JPE.2015.15.6.1517
The wavelet PWM (WPWM) technique has been applied in two-level inverters successfully, but directly applying the WPWM technique to three-level inverters is impossible. This paper proposes a WPWM technique suitable for a single-phase three-level inverter. The work analyzes the control strategy with the WPWM and obtains the design of its parameters. Compared with the SPWM technique for a single-phase three-level inverter under the same conditions, the WPWM can obtain high magnitudes of the output fundamental frequency component, low total harmonic distortion, and simpler digital implementation. The feasibility experiment is given to verify of the proposed WPWM technique.
Reduction of Common Mode Voltage in Asymmetrical Dual Inverter Configuration Using Discontinuous Modulating Signal Based PWM Technique
Reddy, M. Harsha Vardhan ; Reddy, T. Bramhananda ; Reddy, B. Ravindranath ; Suryakalavathi, M. ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1524~1532
DOI : 10.6113/JPE.2015.15.6.1524
Conventional space vector pulse width modulation based asymmetrical dual inverter configuration produces high common mode voltage (CMV) variations. This CMV causes the flow of common mode current, which adversely affects the motor bearings and electromagnetic interference of nearby electronic systems. In this study, a simple and generalized carrier based pulse width modulation (PWM) technique is proposed for dual inverter configuration. This simple approach generates various continuous and discontinuous modulating signals based PWM algorithms. With the application of the discontinuous modulating signal based PWM algorithm to the asymmetrical dual inverter configuration, the CMV can be reduced with a slightly improved quality of output voltage. The performance of the continuous and discontinuous modulating signals based PWM algorithms is explored through both theoretical and experimental studies. Results show that the discontinuous modulating signal based PWM algorithm efficiently reduces the CMV and switching losses.
An Improved Asymmetric Half-Bridge Converter for Switched Reluctance Motor in Low-Speed Operation with Current Regulated Mode
Woothipatanapan, Sakhon ; Chancharoensook, Phop ; Jangwanitlert, Anuwat ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1533~1546
DOI : 10.6113/JPE.2015.15.6.1533
This study presents a novel method for reducing the switching losses of an asymmetric half-bridge converter for a three-phase, 12/8 switched reluctance motor operated in low speed. In particular, this study aims to reduce the switching-off losses of chopping switches in the converter when operated in the current regulated mode (chopping mode). The proposed method uses the mixed parallel operation of IGBT (chopping switch) and MOSFET (auxiliary switch). MOSFET is precisely controlled to momentarily conduct prior to the turn-off interval of the IGBT. Consequently, the voltage across the switches is clamped to approximately zero, substantially decreasing the turn-off switching losses. The analytical expressions of power losses are extensively elaborated. Compared with the conventional asymmetric half-bridge converter, the modified converter can effectively minimize the switching losses. Therefore, the efficiency of the converter is eventually improved. Computer simulation and experimental results confirm the effectiveness of the proposed technique.
A High Performance Permanent Magnet Synchronous Motor Servo System Using Predictive Functional Control and Kalman Filter
Wang, Shuang ; Zhu, Wenju ; Shi, Jian ; Ji, Hua ; Huang, Surong ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1547~1558
DOI : 10.6113/JPE.2015.15.6.1547
A predictive functional control (PFC) scheme for permanent magnet synchronous motor (PMSM) servo systems is proposed in this paper. The PFC-based method is first introduced in the control design of speed loop. Since the accuracy of the PFC model is influenced by external disturbances and speed detection quantization errors of the low distinguishability optical encoder in servo systems, it is noted that the standard PFC method does not achieve satisfactory results in the presence of strong disturbances. This paper adopted the Kalman filter to observe the load torque, the rotor position and the rotor angular velocity under the condition of a limited precision encoder. The observations are then fed back into PFC model to rebuild it when considering the influence of perturbation. Therefore, an improved PFC method, called the PFC+Kalman filter method, is presented, and a high performance PMSM servo system was achieved. The validity of the proposed controller was tested via experiments. Excellent results were obtained with respect to the speed trajectory tracking, stability, and disturbance rejection.
Position Sensorless Control of BLDC Motors Based on Global Fast Terminal Sliding Mode Observer
Wang, Xiaoyuan ; Fu, Tao ; Wang, Xiaoguang ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1559~1566
DOI : 10.6113/JPE.2015.15.6.1559
The brushless DC motor (BLDCM) has many advantages. As a result, it is widely used in electric vehicle (EV) drive systems. To improve the reliability of the motor control system, a position sensorless control strategy based on a sliding mode observer (SMO) is proposed. The global fast terminal sliding mode observer (GFTSMO) is proposed to enhance the control performance of the SMO control system. The advantages of the linear sliding mode and the nonsingular terminal sliding mode (NTSM) are combined in the control strategy. The convergence speed of the system state is enhanced. The motor commutation point is obtained with the observation of the back EMF, and the instantaneous torque value of the motor is calculated. Therefore, the position sensorless control of the BLDCM is realized. Experimental results show that the proposed control strategy can improve the convergence speed, dynamic characteristics and robustness of the system.
Harmonic Analysis of the Effects of Inverter Nonlinearity on the Offline Inductance Identification of PMSMs Using High Frequency Signal Injection
Wang, Gaolin ; Wang, Ying ; Ding, Li ; Yang, Lei ; Ni, Ronggang ; Xu, Dianguo ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1567~1576
DOI : 10.6113/JPE.2015.15.6.1567
Offline inductance identification of a permanent magnet synchronous motor (PMSM) is essential for the design of the closed-loop controller and position observer in sensorless vector controlled drives. On the base of the offline inductance identification method combining direct current (DC) offset and high frequency (HF) voltage injection which is fulfilled at standstill, this paper investigates the inverter nonlinearity effects on the inductance identification while considering harmonics in the induced HF current. The negative effects on d-q axis inductance identifications using HF signal injection are analyzed after self-learning of the inverter nonlinearity characteristics. Then, both the voltage error and the harmonic current can be described. In addition, different cases of voltage error distribution with different injection conditions are classified. The effects of inverter nonlinearities on the offline inductance identification using HF injection are validated on a 2.2 kW interior PMSM drive.
Lyapunov Based Adaptive-Robust Control of the Non-Minimum phase DC-DC Converters Using Input-Output Linearization
Salimi, Mahdi ; Zakipour, Adel ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1577~1583
DOI : 10.6113/JPE.2015.15.6.1577
In this research, a combined adaptive-robust current controller is developed for non-minimum-phase DC-DC converters in a wide range of operations. In the proposed nonlinear controller, load resistance, input voltage and zero interval of the inductor current are estimated using developed adaptation rules and knowing the operating mode of the converter for the closed-loop control is not required; hence, a single controller can be employed for a wide load and line changes in discontinuous and continuous conduction operations. Using the TMS320F2810 digital signal processor, the experimental response of the proposed controller is presented in different operating points of the buck/boost converter. During transition between different modes of the converter, the developed controller has a better dynamic response compared with previously reported adaptive nonlinear approach. Moreover, output voltage steady-state error is zero in different conditions.
Backstepping Control of a Buck-Boost Converter in an Experimental PV-System
Vazquez, Jesus R. ; Martin, Aranzazu D. ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1584~1592
DOI : 10.6113/JPE.2015.15.6.1584
This paper presents a nonlinear method to control a DC-DC converter and track the Maximum Power Point (MPP) of a Photovoltaic (PV) system. A backstepping controller is proposed to regulate the voltage at the input of a buck-boost converter by means of Lyapunov functions. To make the control initially faster and avoid local maximum, a regression plane is used to estimate the reference voltages that must be obtained to achieve the MPP and guarantee the maximum power extraction, modifying the conventional Perturb and Observe (P&O) method. An experimental platform has been designed to verify the validity and performance of the proposed control method. In this platform, a buck-boost converter has been built to extract the maximum power of commercial solar modules under different environmental conditions.
Compensation of Current Offset Error in Half-Bridge PWM Inverter for Linear Compressor
Kim, Dong-Youn ; Im, Won-Sang ; Hwang, Seon-Hwan ; Kim, Jang-Mok ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1593~1600
DOI : 10.6113/JPE.2015.15.6.1593
This paper proposes a novel compensation algorithm of current offset error for single-phase linear compressor in home appliances. In a half-bridge inverter, current offset error may cause unbalanced DC-link voltage when the DC-link is comprised of two serially connected capacitors. To compensate the current measurement error, the synchronous reference frame transformation is used for detecting the measurement error. When an offset error occurs in the output current of the half-bridge inverter, the d-axis current has a ripple with frequency equal to the fundamental frequency. With the use of a proportional-resonant controller, the ripple component can be removed, and offset error can be compensated. The proposed compensation method can easily be implemented without much computation and additional hardware circuit. The validity of the proposed algorithm is verified through experimental results.
PQ Control of Micro Grid Inverters with Axial Voltage Regulators
Chen, Yang ; Zhao, Jinbin ; Qu, Keqing ; Li, Fen ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1601~1608
DOI : 10.6113/JPE.2015.15.6.1601
This paper presents a PQ control strategy for micro grid inverters with axial voltage regulators. The inverter works in the voltage-controlled mode and can help improve the terminal power quality. The inverter has two axial voltage regulators. The 1st regulator involves the output voltage amplitude and output impedance, while the 2nd regulator controls the output frequency. The inverter system is equivalent to a controllable voltage source with a controllable inner output impedance. The basic PQ control for micro grid inverters is easy to accomplish. The output active and reactive powers can be decoupled well by controlling the two axial voltages. The 1st axial voltage regulator controls the reactive power, while the 2nd regulator controls the active power. The paper analyses the axial voltage regulation mechanism, and evaluates the PQ decoupling effect mathematically. The effectiveness of the proposed control strategy is validated by simulation and experimental results.
A Bidirectional Dual Buck-Boost Voltage Balancer with Direct Coupling Based on a Burst-Mode Control Scheme for Low-Voltage Bipolar-Type DC Microgrids
Liu, Chuang ; Zhu, Dawei ; Zhang, Jia ; Liu, Haiyang ; Cai, Guowei ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1609~1618
DOI : 10.6113/JPE.2015.15.6.1609
DC microgrids are considered as prospective systems because of their easy connection of distributed energy resources (DERs) and electric vehicles (EVs), reduction of conversion loss between dc output sources and loads, lack of reactive power issues, etc. These features make them very suitable for future industrial and commercial buildings' power systems. In addition, the bipolar-type dc system structure is more popular, because it provides two voltage levels for different power converters and loads. To keep voltage balanced in such a dc system, a bidirectional dual buck-boost voltage balancer with direct coupling is introduced based on P-cell and N-cell concepts. This results in greatly enhanced system reliability thanks to no shoot-through problems and lower switching losses with the help of power MOSFETs. In order to increase system efficiency and reliability, a novel burst-mode control strategy is proposed for the dual buck-boost voltage balancer. The basic operating principle, the current relations, and a small-signal model of the voltage balancer are analyzed under the burst-mode control scheme in detail. Finally, simulation experiments are performed and a laboratory unit with a 5kW unbalanced ability is constructed to verify the viability of the bidirectional dual buck-boost voltage balancer under the proposed burst-mode control scheme in low-voltage bipolar-type dc microgrids.
Harmonic Elimination and Reactive Power Compensation with a Novel Control Algorithm based Active Power Filter
Garanayak, Priyabrat ; Panda, Gayadhar ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1619~1627
DOI : 10.6113/JPE.2015.15.6.1619
This paper presents a power system harmonic elimination using the mixed adaptive linear neural network and variable step-size leaky least mean square (ADALINE-VSSLLMS) control algorithm based active power filter (APF). The weight vector of ADALINE along with the variable step-size parameter and leakage coefficient of the VSSLLMS algorithm are automatically adjusted to eliminate harmonics from the distorted load current. For all iteration, the VSSLLMS algorithm selects a new rate of convergence for searching and runs the computations. The adopted shunt-hybrid APF (SHAPF) consists of an APF and a series of 7
tuned passive filter connected to each phase. The performance of the proposed ADALINE-VSSLLMS control algorithm employed for SHAPF is analyzed through a simulation in a MATLAB/Simulink environment. Experimental results of a real-time prototype validate the efficacy of the proposed control algorithm.
Line-Interactive UPS for Low-Voltage Microgrids
Zhang, Ping ; Cai, Huanyu ; Zhao, Hengyang ; Shi, Jianjiang ; He, Xiangning ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1628~1639
DOI : 10.6113/JPE.2015.15.6.1628
Line-interactive uninterruptible power supply (UPS) systems are good candidates for providing energy storage within a microgrid. In this paper, a control scheme for a line-interactive UPS system applied in a low-voltage microgrid is presented. It is based on the Q-w and P-E droop control to achieve a seamless transition between grid-connected and stand-alone operation modes. Moreover, a new model for designing the controllers is built in the dq-frame based on the instantaneous power definition. The new-built model takes into account the dynamic performance of the output impedance of the inverter in the dq-frame and can be evaluated in the time domain. Compared to the traditional model based on the instantaneous power definition, the new-built model is more accurate to describe the dynamic performance of the system. Simulation and experimental results obtained with a microgrid consisting of two 40-kW line-interactive UPS systems are given to validate the control strategy of the line-active UPS system and the accuracy of the new-built model.
Integrated Model of Power Electronics, Electric Motor, and Gearbox for a Light EV
Hofman, Isabelle ; Sergeant, Peter ; Van den Bossche, Alex ; Koroglu, Selim ; Kesler, Selami ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1640~1653
DOI : 10.6113/JPE.2015.15.6.1640
This study presents a model of a drivetrain for an integrated design of a light electric vehicle (EV). For the drivetrain of each front wheel of the single-person, battery-powered EV tricycle consists of a battery, an inverter, and an outer rotor permanent magnet synchronous motor (PMSM), which is connected to an in-wheel gearbox. The efficiency of the inverter, motor, and gearbox is analyzed over the New European Driving Cycle. To calculate the losses and efficiency of the PMSM, the power electronics in the inverter and gearbox are used. The analytical models provide a fast, but less accurate result, useful for optimization purposes. To accurately predict the efficiency of the PMSM, a finite element model is used. The models are validated by test setups. Correspondingly, a good agreement between the measurements and the calculated results is achieved. A parameter study is performed to investigate the influence of the detailed component parameters (i.e., outer rotor radius, gear ratio, and number of pole pairs and stator slots) on the average efficiency of the drivetrain.
LCL Resonant Compensation of Movable ICPT Systems with a Multi-load
Hua, Jie ; Wang, Hui-Zhen ; Zhao, Yao ; Zou, Ai-Long ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1654~1663
DOI : 10.6113/JPE.2015.15.6.1654
Compared to LC resonance, LCL resonance has distinct advantages such as a large resonant capability, low voltage and current stresses of the power device, constant voltage or current output characteristics, and fault-tolerance capability. Thus, LCL resonant compensation is employed for a movable Inductive Contactless Power Transfer (ICPT) system with a multi-load in this paper, which achieves constant current output characteristics. Peculiarly, the primary side adopts a much larger compensation inductor than the primary leakage inductor to lower the reactive power, reduce the input current ripple, generate a large current in the primary side, and realize soft-switching. Furthermore, this paper proposes an approximate resonant point for large inductor-ratio LCL resonant compensation through fundamental wave analysis. In addition, the PWM control strategy is used for this system to achieve constant current output characteristics. Finally, an experimental platform is built, whose secondary E-Type coils can ride and move on a primary rail. Simulations and experiments are conducted to verify the effectiveness and accuracy of both the theory and the design method.
A Series Arc Fault Detection Strategy for Single-Phase Boost PFC Rectifiers
Cho, Younghoon ; Lim, Jongung ; Seo, Hyunuk ; Bang, Sun-Bae ; Choe, Gyu-Ha ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1664~1672
DOI : 10.6113/JPE.2015.15.6.1664
This paper proposes a series arc fault detection algorithm which incorporates peak voltage and harmonic current detectors for single-phase boost power factor correction (PFC) rectifiers. The series arc fault model is also proposed to analyze the phenomenon of the arc fault and detection algorithm. For arc detection, the virtual dq transformation is utilized to detect the peak input voltage. In addition, multiple combinations of low- and high-pass filters are applied to extract the specific harmonic components which show the characteristics of the series arc fault conditions. The proposed model and the arc detection method are experimentally verified through a boost PFC rectifier prototype operating under the grid-tied condition with an artificial arc generator manufactured under the guidelines for the Underwriters Laboratories (UL) 1699 standard.
A Design of Wide-Bandwidth LDO Regulator with High Robustness ESD Protection Circuit
Cho, Han-Hee ; Koo, Yong-Seo ;
Journal of Power Electronics, volume 15, issue 6, 2015, Pages 1673~1681
DOI : 10.6113/JPE.2015.15.6.1673
A low dropout (LDO) regulator with a wide-bandwidth is proposed in this paper. The regulator features a Human Body Model (HBM) 8kV-class high robustness ElectroStatic Discharge (ESD) protection circuit, and two error amplifiers (one with low gain and wide bandwidth, and the other with high gain and narrow bandwidth). The dual error amplifiers are located within the feedback loop of the LDO regulator, and they selectively amplify the signal according to its ripples. The proposed LDO regulator is more efficient in its regulation process because of its selective amplification according to frequency and bandwidth. Furthermore, the proposed regulator has the same gain as a conventional LDO at 62 dB with a 130 kHz-wide bandwidth, which is approximately 3.5 times that of a conventional LDO. The proposed device presents a fast response with improved load and line regulation characteristics. In addition, to prevent an increase in the area of the circuit, a body-driven fabrication technique was used for the error amplifier and the pass transistor. The proposed LDO regulator has an input voltage range of 2.5 V to 4.5 V, and it provides a load current of 100 mA in an output voltage range of 1.2 V to 4.1 V. In addition, to prevent damage in the Integrated Circuit (IC) as a result of static electricity, the reliability of IC was improved by embedding a self-produced 8 kV-class (Chip level) ESD protection circuit of a P-substrate-Triggered Silicon Controlled Rectifier (PTSCR) type with high robustness characteristics.