• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.323-326
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• 2003

본 논문에서는 THD 개선을 위한 단순한 구조의 단일 단 PFC를 제안하고 벅 컨버터에 적용하였다. 제안한 회로는 밸리-필 정류회로와 부스팅을 위한 인덕터를 결합하여 단일 능동 소자로 DC/DC 변환 과 PFC를 동시에 수행한다. 제안된 회로에서의 입력전류 모양은 입력전압조건과 PWM 스위칭 시간에 관계되고, 부스팅 인덕터에 의해 능동스위치 차단시간동안 입력 전류를 제어하여 THD를 개선한다. 부스팅 인덕터 채용에 따른 동작해석과 최적 THD를 위한 인덕터를 선정하고 100W출력 단일 단 컨버터를 설계, 제작하였다. 실험에 의한 측정된 결과로 제안된 컨버터의 타당성을 검증하였다.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.1121-1124
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• 1999

Linear motor is able to produce line movement without rotary-to-line converter at the system required line moving. Thus Linear motor has no gear, screw, belt for line movement. Therefore it has some advantage which decrease friction loss, noise, vibration, maintenance effort and prevent decay of control performance due to backlash. This paper proposes the estimation method of unknown parameters from the BLDC Linear motor and determine the PI controller gain through this estimation. Each control movement that is current, speed, position control, and PWM wave generation is performed on Processor, which is DSP(Digital Signal Processor), having high speed performance. PI theory is adopted to each for controller for control behavior More fast convergence to command position is accomplished by applying the new velocity locus which derived from position error.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.648-653
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• 1998

The conventional three-phase rectifier with bulky LC output filter has been widely used in the industry because of its distinctive advantages over the active power factor correction rectifier such as simple circuit, high reliability, and low cost. Over than 0.9 power factor can be achieved, which is acceptable in most of industry applications. This rectifier, however, is not easy to use for high power density applications since the LC filter is bulky and heavy. To solve this problem, a new simple rectifier is presented in this paper. By eliminating the bulky LC filter from the conventional diode rectifier without losing most of the advantages of the conventional rectifier, very high power density power conversion with high power factor can be achieved. Operation principle and design considerations are illustrated and verified by Pspice simulation and experimental results from a prototype of 3.3 kW rectifier followed by 100KHz zero voltage switching full bridge PWM converter

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.6
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• pp.486-494
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• 2012

In this paper, we proposes the three-phase embedded Z-source inverter consisting of the three embedded Z-source converters and it's the output voltage control method. Each embedded Z-source converter can produce the bipolar output capacitor voltages according to duty ratio D such as single-phase PWM inverter. The output AC voltage of the proposed system is obtained as the difference in the output capacitor voltages of each converter, and the L-C output filter is not required. Because the output AC voltage can be stepped up and down, the boost DC converter in the conventional two-stage inverter is unnecessary. To confirm the validity of the proposed system, PSIM simulation and a DSP based experiment were performed under the condition of the input DC voltage 38V, load $100{\Omega}$, and switching frequency 30kHz. Each converter is connected by Y-connection for three-phase loads. In case that the output phase voltage is the same $38V_{peak}$ as the input DC voltage and is the 1.5 times($57V_{peak}$), the simulation and experimental results ; capacitor voltages, output phase voltages, output line voltages, inductor currents, and switch voltages were verified and discussed.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1161-1162
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• 2006

본 논문은 3[kW]급 연료전지와 연료전지의 저전압$[40{\sim}60[Vdc]$)을 승압(380vdc)하기 위한 풀-브리지 DC-DC 컨버터, 그리고 승압된 링크전압을 교류 상용전압(220[Vac], 60[Hz)으로 변환하기위한 단상 풀-브리지 인버터로 구성된 연료전지 발전용 전력변환시스템 중 연료전지 시스템용 DC-DC 컨버터를 제안하였다. 제안한 연료전지 시스템용 DC-DC 컨버터는 변압기 2차측에 배전류 정류회로를 삽입하여 기존의 고주파 변압기 보다 간단하면서 무게 및 부피를 줄였다. 그리고 위상 천이 PWM 제어로 출력 전압을 가변시켜 영전압 스위칭을 달성 함으로써 스위칭 손실을 줄였으며. 효율을 95%이상 달성 하였다.