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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Power Electronics
Journal Basic Information
Journal DOI :
The Korean Institute of Power Electronics
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Volume & Issues
Volume 7, Issue 4 - Oct 2007
Volume 7, Issue 3 - Jul 2007
Volume 7, Issue 2 - Apr 2007
Volume 7, Issue 1 - Jan 2007
Selecting the target year
Synthesis and Experimental Implementation of DSP Based Backstepping Control of Positioning Systems
Chang, Jie ; Tan, Yaolong ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 1~12
Novel nonlinear backstepping control with integrated adaptive control function is developed for high-performance positioning control systems. The proposed schemes are synthesized by a systematic approach and implemented based on a modern low-cost DSP controller, TMS320C32. A baseline backstepping control scheme is derived first, and is then extended to include a nonlinear adaptive control against the system parameter changes and load variations. The backstepping control utilizes Lyapunov function to guarantee the convergence of the position tracking error. The final control algorithm is a convenient in the implementation of a practical 32-bit DSP controller. The new control system can achieve superior performance over the conventional nested PI controllers, with improved position tracking, control bandwidth, and robustness against external disturbances, which is demonstrated by experimental results.
Design Consideration of Half-Bridge LLC Resonant Converter
Choi, Hang-Seok ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 13~20
LLC resonant converters display many advantages over the conventional LC series resonant converter such as narrow frequency variation over wide range of load and input variation and zero voltage switching even under no load conditions. This paper presents analysis and design consideration for the half bridge LLC resonant converter. Using the fundamental approximation, the gain equation is obtained, where the leakage inductance in the transformer secondary side is also considered. Based on the gain equation, the practical design procedure is investigated to optimize the resonant network for a given input/output specifications. The design procedure is verified through an experimental prototype of the 115W half-bridge LLC resonant converter.
Investigation of PID Fuzzy Controller for Output Voltage Regulation of Current-Doubler-Rectified Asymmetric Half-Bridge DC/DC Converter
Chung, Gyo-Bum ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 21~27
This paper investigates a PID fuzzy controller for output voltage regulation of a current-doubler-rectified asymmetric half-bridge (CDRAHB) DC/DC converter. The controller is a PD-type fuzzy controller in parallel with a linear integral controller. The PD type fuzzy controller is for providing the varying gain at the different operating conditions to regulate the output voltage. The linear integral controller is for removing the steady-state error of the output voltage. In order to show the outstanding dynamic characteristics of the proposed controller, PSIM simulation studies are carried out and compared to the results for which the conventional loop gain design method is used.
A New PWM-Controlled Quasi-Resonant Converter for a High Efficiency PDP Sustaining Power Module
Lee, Woo-Jin ; Choi, Seong-Wook ; Kim, Chong-Eun ; Moon, Gun-Woo ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 28~37
A new PWM-controlled quasi-resonant converter for a high efficiency PDP sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the resonant capacitor with a bi-directional auxiliary circuit, while the main switches are operating at a fixed duty ratio and fixed switching frequency. Hence, the waveforms of the currents can be expected to be optimized from the view-point of conduction loss. Furthermore, the proposed converter has good ZVS capability, simple control circuits, no high voltage ringing problem of rectifier diodes, no DC offset of the magnetizing current and low voltage stresses of power switches. In this paper, operational principles, features of the proposed converter, and analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit using the PWM method.
A Study on the Equivalent Model of an External Electrode Fluorescent Lamp Based on Equivalent Resistance and Capacitance Variation
Cho, Kyu-Min ; Oh, Won-Sik ; Moon, Gun-Woo ; Park, Mun-Soo ; Lee, Sang-Gil ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 38~43
An External Electrode Fluorescent Lamp (EEFL) has longer lifespan, higher power efficiency and higher luminance than a Cold Cathode Fluorescent Lamp (CCFL). Moreover, it is easy to drive them in parallel. Therefore, the EEFL is expected to quickly replace the CCFL in LCD backlight systems. However, the EEFL has more complex characteristics than the CCFL with a resistive component, because it has both a resistive component by plasma and a capacitive component by external electrode. In this paper, values of resistance and capacitance are measured at several power levels and at several operating frequencies. They are expressed by a numeral formula based on a linear approximation that represents the equivalent resistance and capacitance as a function of power. Then we made block diagram of the equivalent circuit model using numerical expressions. Simulation waveforms and experimental results are presented to verify the feasibility of the equivalent model.
Modified Ac-Dc Single-Stage Converters
Moschopoulos, Gerry ; Liu, Yan ; Bassan, Sondeep ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 44~54
Ac-dc power conversion can either be done with two separate converter stages or with a single converter stage. Two-stage ac-dc converters, however, can be costly and complex, while the performance of single-stage converters is compromised due to a reduced number of components. Several researchers have therefore proposed adding some sort of auxiliary circuit consisting of a second switch and some passive elements to single-stage converters to improve their performance. Although these modified single-stage converters may have two converters, they are not two-stage converters as they do not have two separate and independently controlled converters that are always operating to convert power from one form to another. In this paper, the operation of ac-dc single-stage converters is first reviewed and their strengths and weaknesses are noted. The operation of several modified single-stage converters, including one proposed by the authors, is then discussed, and the paper concludes by presenting experimental results that confirm the feasibility of the proposed converter.
A Simple ZVT PWM Single-Phase Rectifier with Reduced Conduction Loss and Unity Power Factor
Kim, In-Dong ; Choi, Seong-Hun ; Nho, Eui-Cheol ; Ahn, Jin-Woo ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 55~63
This paper proposes a simple unity power factor zero-voltage-transition (ZVT) pulse-width-modulated (PWM) single-phase rectifier, which features reduced switching and conduction losses. The switching loss reduction is achieved by a simple auxiliary commutation circuit, and the conduction loss reduction is achieved by employing a single-stage converter, rather than a typical double-stage converter comprising of a front-end rectifier and a boost rectifier. Furthermore, thanks to good features such as a simple PWM control at constant frequency, low switch stress, low Var rating of commutation circuits, and simple power circuit structure, it is suitable for high power applications. The principles of operation are explained in detail, and a major characteristics analysis and the experimental results of the new converter are also included in this paper.
A Novel Active Anti-islanding Method for Grid-connected Photovoltaic Inverter
Jung, Young-Seok ; Choi, Jae-Ho ; Yu, Gwon-Jong ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 64~71
This paper proposes a novel active frequency drift (AFD) method to improve the islanding detection performance with minimum current harmonics. To detect the islanding phenomenon of grid-connected photovoltaic (PV) inverters concerning the safety hazards and possible damage to other electric equipment, anti-islanding methods have been described. The AFD method that uses chopping fraction (cf) enables the islanding detection to drift up (or down) the frequency of the voltage during the islanding situation. However, the performance of the conventional AFD method is inefficient and causes difficulty in designing the appropriate cf value to meet the limit of harmonics. In this paper, the periodic chopping fraction based on a novel AFD method is proposed. This proposed method shows the analytical design value of cf to meet the test procedure of IEEE Std. 929-2000 with power quality and islanding detection time. To verify the validation of the proposed method, the islanding test results are presented. It is confirmed that the proposed method has not only less harmonic distortion but also better performance of islanding detection compared with the conventional AFD method.
A New Control Scheme for Unified Power Quality Compensator-Q with Minimum Power Injection
Lee, Woo-Cheol ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 72~80
Voltage sags are one of the most frequently occurring power quality problems challenging power systems today. The Unified Power Quality Conditioner (UPQC) is one of the major custom power solutions that are capable of mitigating the effect of supply voltage sags at the load or Point of Common Coupling (PCC). A UPQC-Q employs a control method in which the series compensator injects a voltage that leads the supply current by
so that the series compensator at steady state consumes no active power. However, the UPQC-Q has the disadvantage that its series compensator needs to be overrated. Thus it cannot offer effective compensation. This paper proposes a new control scheme for the UPQC-Q that offers minimum power injection. The proposed minimum power injection method takes into consideration the limits on the rated voltage capacity of the series compensator and its control scheme. The validity of the proposed control scheme is investigated through simulation and experimental results.
Automatic Turn-off Angle Control for High Speed SRM Drives
Nashed Maged N.F. ; Ohyama Kazuhiro ; Aso Kenichi ; Fujii Hiroaki ; Uehara Hitoshi ;
Journal of Power Electronics, volume 7, issue 1, 2007, Pages 81~88
This paper presents a new approach to the automatic control of the turn-off angle used to excite the Switched Reluctance Motor (SRM) employed in electric vehicles (EV). The controller selects the turn-off angle that supports and improves the performance of the motor drive system. This control scheme consisting of classical current control and speed control depends on a lookup table to take the best result of the motor. The turn-on angle of the main switches of the inverter is fixed at
and the turn-off angle is variable depending on the reference speed. The motor, inverter and control system are modeled in Simulink to demonstrate the operation of the system.