• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.154-156
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• 2008

본 논문은 대용량 충 방전 커패시터 부하를 갖는 CCPS (Capacitor Charging Power Supply)의 충전시간 제어방법을 제안한다. 기존의 대용량 Capacitor charger들은 LC공진탱크 및 스위칭 주파수를 개 루프 방식으로 제어한다. 이와 같은 제어 방법은 LC 공진탱크의 파라미터 변화로 인해 충전시간 제어가 불가능하다. 본 논문은 이러한 문제점을 해결하기 위해 Zero-crossing 방법을 이용 전류의 공진주파수를 검출한 뒤 스위칭 주파수를 가변 함으로서 원하는 시간과 안정성을 동시에 만족 할 수 있는 피드백 제어 방법을 제안한다.

• 대한전기학회논문지
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• 제41권2호
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• pp.144-155
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• 1992

A design of a highly stable current-controlled power supply combining the phase-controlled rectifier (PCR), passive filter and active filter is investigated. A digital phase-looked voltage control (PLVC) with a capability of compensating the thyristor firing angles under unvalanced power source is proposed` otherwise the PCR output voltage has low-order subharmonics whose suppression requires a bulky passive filter. The digital PLVC has a fast dynamic characteristics as an inner control loop of the PCR. To suppress further the output ripple, an active filter using a transformer is introduced and its design is described through the frequency domain analysis. An optimal integral, proportional and measurable variable feedback (IPM) controller is designed using the time-weighted performance index based on the time domain analysis. The design method based on the time-weighted performance index gives better response characteristics than that based on the conventional performance index. It is also shown via experimental results that the proposed scheme gives better response characteristics than that based on the conventional performance index. It is also shown via experimental results that the proposed scheme gives good dynamic and static performances.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권10호
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• pp.610-617
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• 2004

This paper presents a novel high frequency generating circuit integrated chopper-inverter using ZVS with high power-factor. The proposed topology is integrated half-bridge boost rectifier as power factor corrector(PFC) and half-bridge high frequency resonant inverter into a single-stage. The input stage of the half-bridge boost rectifier works in discontinuous conduction mode(DCM) with constant duty cycle and variable switching frequency. So that a boost converter makes the line current follow naturally the sinusoidal line voltage waveform. Simulation results have demonstrated the feasibility of the proposed high frequency resonant inverter. Characteristics values based on characteristics analysis through circuit analysis is given as basis data in design procedure. Also, experimental results are presented to verify theoretical discussion. This proposed inverter will be able to be practically used as a power supply in various fields as induction heating applications. fluorescent lamp and DC-DC converter etc.

• 전력전자학회논문지
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• 제10권3호
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• pp.248-256
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• 2005

본 논문에서는 중$\cdot$대용량 고밀도 전원 장치에 적합한 플랫 트랜스포머(Flat Transformer)를 사용하여 다양한 출력의 DC/DC 변환장치를 설계하는 방법을 제시하였다. 플랫 트랜스포머 모듈은 다수의 트랜스포머를 병렬로 구성하여 제작하고, 이차 권선이 항상 1턴으로 구성되므로 기존의 트랜스포머에 비해 누설 인덕턴스가 크게 감소하게 되어 고주파 스위칭에 적합한 형태를 가지고 있다. 본 논문에서는 플랫 트랜스포머의 성능을 증명하기 위하여 750W급 AC/DC 변환기를 구성하여 다양한 출력을 갖는 전원 장치를 제작/실험하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1196-1198
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• 2002

A novel single-stage half-bridge high frequency resonant inverter using ZVS(Zero Voltage Switching) with high input power factor suitable for induction heating applications is presented in this paper. The proposed high frequency resonant inverter integrates half-bridge boost rectifier as power factor corrector(PFC) and half-bridge resonant inverter into a single stage. The input stage of the half-bridge boost rectifier is working in discontinuous conduction mode (DCM) with constant duty cycle and variable switching frequency. So that a high power factor is achieved naturally. Simulation results through the Pspice have demonstrated the feasibility of the proposed inverter. This proposed inverter will be able to be practically used as a power supply in various fields as induction heating applications, DC-DC converter etc.

• 전력전자학회논문지
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• 제22권1호
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• pp.36-43
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• 2017

This paper describes a hybrid multi-output three-level DC/DC converter suitable for a wide, high-input voltage range of an auxiliary power supply for a high-power photovoltaic generating system. In a high-power photovoltaic generating system, the solar panel output voltage depends on solar radiation quantity and varies from 450Vdc to 1100Vdc. The proposed hybrid multi-output three-level DC/DC converter, which is an auxiliary power supply, would be used as power source for control printed circuit boards and relay and cooling fans in a high-power photovoltaic generating system. The proposed multi-output ($24V_{DC}/30A$, $230V_{DC}/5A$) hybrid three-level boost converter, which uses an energy recovery snubber, is controlled by variable-frequency and phase-shifted modulations and can achieve zero-voltage switching with all operating conditions of input voltage and load range. Experimental results of a 2kW prototype are evaluated and implemented to verify the performance of the proposed converter.

• ETRI Journal
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• 제26권5호
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• pp.486-492
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• 2004

The emergence of wide channel bandwidth wireless standards requires the use of a highly linear, wideband integrated CMOS baseband chain with moderate power consumption. In this paper, we present the design of highly linear, wideband active RC filters and a digitally programmable variable gain amplifier. To achieve a high unity gain bandwidth product with moderate power consumption, the feed-forward compensation technique is applied for the design of wideband active RC filters. Measured results from a $0.5{\mu}m$ CMOS prototype baseband chain show a cutoff frequency of 10 MHz, a variable gain range of 33 dB, an in-band IIP3 of 13 dBV, and an input referred noise of 114 ${\mu}Vrms$ while dissipating 20 mW from a 3 V supply.

• 전기의세계
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• 제17권1호
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• pp.6-10
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• 1968

To control of the speed of induction Motor, a variable frequency power supply is needed. But this New type induction Motor Constitute stator and Rotor with New principle, its speed can be easily and widely Controlled by changing phase of the stator, and start at low current than rating without starter. Also, its no load current is same as shart current, and speed increase in proportion to current. On this points this induction Motor for speed control is different from induction Motor using Now.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1190-1192
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• 2003

This paper presents a novel single-stage high frequency resonant inverter link type DC-DC converter using zero voltage switching with high input power factor. The proposed high frequency resonant converter integrates half-bridge boost rectifier as power factor corrector (PFC) and half-bridge resonant converter into a single stage. The input stage of the half-bridge boost rectifier is working in discontinuous conduction mode(DCM) with constant duty cycle and variable switching frequency. So that boost converter make the line current follow naturally the sinusoidal line voltage waveform. Experimental results have demonstrated the feasibility of the proposed DC-DC converter. This proposed converter will be able to be practically used as a power supply in various fields as induction heating applications, DC-DC converter etc.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.990-992
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• 2002

30kW electrical power conversion system is delveloped for the variable speed wind turbine system. In the wind energy conversion system(WECS) a synchronous generator with field current excitation converts the mechanical energy into electrical energy. As the voltage and frequency of generator output vary according to the wind speed, a dc/dc boosting chopper is utilized to maintain constant dc link voltage. Grid connection type PWM inverter supply currents into the utility line by regulating the dc link voltage. The active power is controlled by q-axis current which the reactive power can be controlled by d-axis current reference change. The phase angle of utility voltage is detected using s/w PLL(Phased Locked Loop) in d-q synchronous reference frame. This scheme gives a low cost power solution for variable speed WECS.