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5kW급 계통연계형 단상 배터리 충전기의 구현 및 실험
안현성(Hyun-Sung An),이우종(Wujong Lee),문병호(Byung-Ho Mun),박일규(Il-Kyu Park),정선용(Seon-Yong Jung),김영록(Youngroc Kim),차한주(Hanju Cha1) 전력전자학회 2013 전력전자학회 논문지 Vol.18 No.1
This paper explains control methods of single-phase grid connected battery charger. Charging mode is control by Constant Current - Constant Voltage method and discharging mode is controlled by active-reactive power control method. Current control method is based on the synchronous reference frame(SRF) PI controller, and the second harmonic of battery current is compensated by an added L-C resonant circuit. Feasibility of the proposed control methods is verified through experiment with a prototype of 5kW single-phase grid connected battery charger.
Comparison of PWM Strategies for Three-Phase Current-fed DC/DC Converters
Hanju Cha,Soonho Choi,Byung-Moon Han 전력전자학회 2008 JOURNAL OF POWER ELECTRONICS Vol.8 No.4
In this paper, three kinds of PWM strategies for a three-phase current-fed dc/dc converter are proposed and compared in terms of losses and voltage transfer ratio. Each PWM strategy is described graphically and their switching losses are analyzed. With the proposed PWM C strategy, one turn-off switching of each bridge switch is eliminated to reduce switching losses under the same switching frequency. In addition, RMS current through the bridge switches is lowered by using parallel connection between two bridge switches and thus, conduction losses of the switches are reduced. Further, copper losses of the transformer are decreased due to the reduced RMS current of each transformer’s winding. Therefore, total losses are minimized and the efficiency of the converter is improved by using the proposed PWM C strategy. Digital signal processor (DSP: TI320LF2407) and a field-programmable gate array (FPGA: EPM7128) board are used to generate PWM patterns for three-phase bridge and clamp MOSFETs. A 500W prototype converter is built and its experimental results verify the validity of the proposed PWM strategies.
Comparison of PWM Strategies for Three-Phase Current-fed DC/DC Converter
Hanju Cha,Soonho Choi 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-
In this paper, three kinds of PWM strategies for a three-phase current-fed dc/dc converter are proposed and compared on the basis of reduced switching losses and improved efficiency. Each PWM strategy is described graphically and their switching losses are analyzed. Digital signal processor (DSP: TI320LF2407) and a fieldprogrammable gate array (FPGA: EPM7128) board are used to generate PWM patterns for three-phase bridge and clamp MOSFETs. 500W prototype converter is built and its experimental results verify the validity of the proposed PWM strategies.
Cha Hanju,Seo Joungjin 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3
The 1st author name is given erroneously. It needs to be corrected from “Jounjin Seo” to “Joungjin Seo”.
3상 매트릭스 컨버터의 Simple V<SUB>max</SUB>-V<SUB>mid</SUB> 전압 변조 방법
차한주(Hanju Cha),임현주(Hyunjoo Lim) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.4
본 논문에서는 AC-AC 직접 변환 방식인 매트릭스 컨버터의 진압 변조 방법 중 하나인 V<SUB>max</SUB>-V<SUB>mid</SUB> PWM 변조 방법을 간략화한 simple V<SUB>max</SUB>-V<SUB>mid</SUB> 진압 변조 방법에 대해 소개한다. V<SUB>max</SUB>-V<SUB>mid</SUB> 진압 변조 방법은 실행 전에 입력전압 위상각(θ<SUB>E</SUB>)을 판별하는 PLL(Phase Looked Loop)과정을 거친 후, 얻은 위상 정보를 사용하여 게이트 신호를 만들어 낸다 하지만 PLL의 사용이 연산 시간의 딜레이를 발생시키고, 처리과정을 복잡하게 만드는 단점으로, PLL과정을 생략하여 입력 진암의 크기 정보만으로 섹터를 판별하고 게이트 신호를 발생시켜 스위치를 조작하는 변조 방법을 사용하였다. 이로 인해 연산시간의 단축과 처리 과정의 축소 등의 이점을 취하고, 이를 시뮬레이션으로 검증한다.
Study and Design of L-C-L Filter for Single-Phase Grid-Connected PV Inverter
차한주(Hanju Cha),부우충기엔(Trung-Kien Vu) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.4
Nowadays, the LCL-filter type becomes an attractive grid interfacing for grid-connected Voltage Source Inverter (VSI). LCL-filter can render the current harmonics attenuation around the switching frequency by using smaller inductance than L-filter. This paper presents a study about the LCL-filter design for single-phase grid-connected inverter in Photovoltaic (PV) system. According to the expected current ripple, the inductances of the filter can be determined. Based on the absorbed reactive power on capacitor, the capacitance can be calculated. Due to the theoretical analysis, a LCL-filter based single phase grid connected inverter control system are simulated. The studied simulation results are given to validate the theoretical analysis.
차한주(Hanju Cha),강영주(Yeongju Kang),안태풍(Taepung Ahn) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.10
부스트 컨버터를 사용해 낮은 직류 전압을 보다 높은 전압으로 승압시킴에 있어 기존 단상이 아닌 다상의 인터리브드 방식의 컨버터를 채택하였다. 인터리브 방식이 갖는 이론적 장점은 전류 경로의 확장으로 그 흐름이 배분되고, 이로 인해 전류 리플크기의 저감과 더불어 컨버터 제작과정에서 부품의 용량 및 부피를 감소시킬 수 있는 이점을 얻는다. 본 논문에서는 인터리브 방식의 채택으로 얻을 수 있는 장점을 실험을 통해 입증, 3상 인터리브 방식 컨버터의 우수성을 보인다.
3상 매트릭스 컨버터에 사용되는 옵셋전압 PWM방법과 V<SUB>max</SUB>-V<SUB>mid</SUB> PWM 방법의 비교분석
車翰周(Hanju Cha),金宇中(Woojung Kim) 대한전기학회 2009 전기학회논문지 Vol.58 No.2
In this paper, comparative analysis of offset voltage PWM method and Vmax-Vmid PWM method for three-phase matrix converter is addressed by using a simple analytical and graphical method. Offset voltage PWM method calculates PWM patterns in terms of offset voltage and variable slope of carrier, and it simplifies matrix converter modulation algorithm significantly. Vmax-Vmid PWM method generates patterns by using two phases and maintaining a remaining phase to base phase, and it is implemented in the industrial products. The most important performance criterion of modulation method is a magnitude of current ripples and it is analytically modelled. The graphical illustration of theses complex multi variable functions make per-carrier cycle and per fundamental cycle behavior of two PWM methods understood. Two modulation methods are analysed with the analytical formulas and graphics, and the analysis shows offset voltage PWM method is superior to Vmax-Vmid PWM method with respect to input current ripples and output voltage ripples.