• 센서학회지
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• 제14권5호
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• pp.350-356
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• 2005

We have developed a dual-channel type automatic measurement system to evaluate AC-DC current transfer difference of the thermal current converter(TCC) which is primary standard of AC current. The output drift effect of the TCC is minimized by measuring simultaneously the output voltages of two TCCs using voltmeter. Furthermore, the offset voltage of the voltmeter is cancelled nearly out by taking the average values of two outputs of TCCs measured with the forward-reverse directions using dual channel scanner. The uncertainties of the automatic system were 7 to $86{\mu}A/A$ for 3 mA to 10 A at 40 Hz to 20 kHz, which were evaluated by the comparisons between adjacent range of TCCs and inter-comparison with national measurement institute of Germany(PTB). The capability for ac-dc transfer difference measurement was improved by one order compared with that for the manual ac-dc measurement system.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권9호
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• pp.590-597
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• 2000

Design of single state AC-DC converter with high power factor for low level applications is proposed. The proposed converter is obtained from the integration of a buck-boost converter and the half-bridge DC-DC converter. This converter gives the good power factor correction low line current harmonic distortions and tight output voltage regulations. This converter also has a high efficiency by employing an soft switching method and synchronous rectifier. The modelling and detailed analysis for the proposed converter are performed. To verify the performance of the proposed converter a 100W converter has been designed

• 조명전기설비학회논문지
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• 제19권8호
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• pp.102-108
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• 2005

본 논문에서는 소프트 스위칭에 의한 새로운 고역률 승압형 AC-DC 컨버터가 제안되고 입력전류의 파형 및 고조파분석에 대해 상세히 해석된다. 시비율 일정의 전류불연속 제어에 의해 동작되는 제안된 컨버터의 입력전류는 교류 입력전압의 크기에 비례한 불연속적인 펄스열의 정현파 형태로 되어 입력역률을 개선시킨다. 또한 제안된 컨버터는 소프트 스위칭을 위한 공진동작에 의해 무손실 스너버 커패시터의 입력측 에너지 유입에 따른 역률증대의 효과를 가지며, 기존의 고역률 승압형 AC-DC 컨버터와 비교되어 입력전류의 수학적 분석과 컴퓨터 시뮬레이션, 실험결과 등에 의해 그 우수성이 입증된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.125-128
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• 2006

This paper presents a novel type soft switching PWM power frequency AC-AC converter using bidirectional active switches or single phase utility frequency AC-high frequency AC matrix converter. This converter can directly convert utility frequency AC (UFAC, 50Hz/60Hz) power to high frequency AC (HFAC) power ranging more than 20kHz up to 100kHz. A novel soft switching PWM prototype of high frequency multi-resonant PWM controlled UFAC-HFAC matrix converter using antiparallel one-chip reverse blocking IGBTs manufactured by IXYS corp. is based on the soft switching resonance with asymmetrical duty cycle PWM strategy. This single phase UFAC-HFAC matrix converter has some remarkable features as electrolytic capacitor DC busline linkless topology, unity power factor correction and sine-wave line current shaping, simple configuration with minimum circuit components, high efficiency and downsizing. This series load resonant UFAC-HFAC matrix converter, incorporating bidirectional active power switches is developed and implemented for high efficiency consumer induction heated food cooking appliances in home uses and business-uses. Its operating performances as soft switching operating ranges and high frequency effective power regulation characteristics are illustrated and discussed on the basis of simulation and experimental results.

• Journal of Advanced Marine Engineering and Technology
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• 제40권4호
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• pp.348-352
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• 2016

본 논문은 적정 전압 여자를 적용한 스위치드 릴럭턴스 전동기의 효율 개선에 대하여 기술한다. 세탁기와 같이 적용 속도에 큰 차이가 있는 부하의 경우 일정한 직류링크전압으로는 효율 개선에 어려움이 있다. 저속운전영역에서 과도한 직류전압의 영향을 줄이기 위해 보통 사용되고 있는 구동회로내의 다이오드 정류기 대신 SCR을 사용한 AC-DC 컨버터가 SRM 드라이버에 포함된다. AC-DC 컨버터는 저속에 알맞은 적정한 여자전압을 공급한다. 실험결과를 통하여 저속영역에서 효율이 개선됨을 확인하였다.

• 전자공학회논문지S
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• 제34S권9호
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• pp.118-125
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• 1997

This paper proposed a new partial resonant 3.PHI. AC-DC boost converter of high efficiency using lossless snubber. The proposed converter, DCM (Discontinuous Current Mode) has a merit of simple controlled circuit because the input current control discontinuously. But turned off switching loss and stress of the switching device increase when the switch turned off at the peak of current. Therefore, the paper improves efficiency by adopting the PRS$^{2}$(Partial Resonant Soft Switching) in 3.PHI. AC-DC boost converter and makes the unity power factor. The PRS$^{2}$ is reduced a current/voltage stresses of switching devices. Also, a DCMPRS$^{2}$M(Discontinuous Conduction Mode Partial Resonant Soft Switching Method) appear the current and voltage equation of this circuit. The paepr examine in a 3.PHI. AC-DC boost converter and show the result of that.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.960-961
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• 2006

In this paper, a static var compensator using three phase PWM Watkins-Johnson AC-AC converter is presented. The PWM Watkins-Johnson AC-AC converter is modelled by using circuit DQ transformation whereby the basic DC characteristics equation is analytically obtained. Finally, the PSIM simulation shows the validity of the modelling and analysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.116-118
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• 2005

In this paper, a three phase PWM noninverting Buck-Boost AC-AC converter for WCF applications is presented. The PWM noninverting Buck-Boost AC-AC converter is modelled by using vector DQ transformation whereby the basic DC characteristics equation is analytically obtained. Finally, the PSIM simulation shows the validity of the modelling and analysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.119-121
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• 2005

In this paper, a three phase PWM Watkins-Johnson AC-AC converter for VVCF applications is presented. The PWM Watkins-Johnson AC-AC converter is modelled by using vector DQ transformation whereby the basic DC characteristics equation is analytically obtained. Finally, the PSIM simulation shows the validity of the modelling and analysis.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.122-124
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• 2005

In this paper, a three phase PWM Zeta AC-AC converter for VVCF applications is presented. The PWM Zeta AC-AC converter is modelled by using vector DQ transformation whereby the basic DC characteristics equation is analytically obtained. Finally, the PSIM simulation shows the validity of the modelling and analysis.