• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1244-1246
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• 2003

Conventional Switched Mode Power Supplies(SMPS) with diode-capacitor rectifier have distorted input current waveform with high harmonic content. Typically, these SMPS have a power factor lower than 0.65. To improve with this problem. the power factor correction(PFC) circuit of power supplies has to be introduced. Specially, to reduce size and manufacture cost of power conversion device, the single-stage PFC converter is increased to demand as necessary of study. In this case single-stage PFC converter has been used DC-DC converter with boost converter. However in this paper, it is studied flyback converter of high power factor, high efficiency by feedforward control. Also, the validity of designed and manufactured high power factor flyback converter is confirmed by simulation and experimental results.

• 한국정보전자통신기술학회논문지
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• 제10권3호
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• pp.206-212
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• 2017

본 논문은 대용량 유도전동기의 기동특성을 분석하였다. 유도전동기 토크는 전류와 자속의 곱으로서 이 자속을 발생시키기 위해서는 여자전류에 해당되는 무효전력이 필요하다. 유도전동기에 필요한 무효전력을 공급하는 방법으로 역률 보상장치를 사용하여 전원측을 대신하여 공급하는 방법을 많이 사용하는데, 역률 보상장치를 사용할 경우 피상전력을 줄일 수 있어 역률을 향상시킬 수 있다. 역률을 개선하기 위한 보상장치를 설치하는 방법으로 부하마다 설치하는 경우와 전체를 일괄 보상하는 방법으로 고압 대용량의 부하로서 일정한 운전패턴을 가지고 있는 경우에는 주로 개별보상이 주로 사용된다. 일반적으로 대용량 유도전동기는 기동 보호장치를 이용하지만 이 논문은 전전압 기동시의 특성을 분석하는 가상의 상황을 가정하여 기동특성에 대한 이론과 실제의 운전특성을 측정 분석하고 역률개선 콘덴서를 이용하여 기동특성을 개선해 보았다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권5호
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• pp.238-245
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• 2003

In this paper, a single Phase voltage source voltage-controlled active power filter(APF) for power quality improvement was proposed. The proposed APF has the performance of harmonic suppression and unity power factor correction. The performance of harmonic suppression can be obtained by controlling the waveshape of the APF output voltage to be sine wave. And, unity power factor is controlled by the reactive power control loop of the APF output. Simulation and experimental results using diode rectifier showed that the voltage-controlled APF, unlike the current-controlled APF, can reduce the voltage harmonics as well as current harmonics. Also the results showed that the input dover factor and power quality were greatly improved.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.423-431
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• 1997

A new single-stage/single-switched forward converter with magnetic coupled nondissipa-tive snubber is proposed. The proposed converter gives the good power factor correction (PFC), low current harmonic distortion, and tight output voltage regulation. The prototype shows the IEC 555-2 requirements are met satisfactorily with nearly unity power factor. This proposed converter with magnetic coupled nondissipative snubber is particularly suited for low power level power supply applications.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 추계학술발표회
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• pp.979-980
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• 2005

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.536-538
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• 2018

This paper introduces an enhanced interleaved (IL) PFC (Power Factor Correction) boost converter typed 650V Intelligent Power Module (IPM), which is fully optimized hybrid IGBT converter modules; Silicon (Si) IGBT and Silicon Carbide (SiC) diode, for up to 10kW HVAC (Heating, Ventilation, and Air Conditioning) systems. It utilizes newly developed $4^{th}$ Generation Field Stop (FS) trench IGBTs, $EXTREMEFAST^{TM}$ anti-paralleled diodes, SiC Junction Barrier Schottky (JBS) diodes, Bridge rectifiers, Multi-function LVIC, and Built-in thermistor provide good reliable characteristics for the entire system. This module also takes technical advantage of DBC (Direct Bonded Copper) substrate for the better thermal performance. It is shown that the Si IGBT/SiC diode hybrid IL PFC module can achieve excellent EMI performance and greatly enhance the power handling capability or switching frequency of various applications compared to the Si IGBT/Diode. This paper provides an overall description of the newly developed 650V/50A Hybrid SiC IL PFC IPM product.

• 조명전기설비학회논문지
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• 제28권1호
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• pp.16-28
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• 2014

This paper presents a novel high-power-factor circuit topology of AC to AC current-fed type high frequency resonant inverter which includes the function of power factor correction(PFC) in the proposed inverter to operate the AC input block with high power factor. The proposed circuit topology of AC to AC current fed type high resonant inverter removes DC link electrolytic capacitor and has also the one of power factor correction(PFC) in the inverter circuit without an additional PFC circuit since the input current by constituting it in parallel as an unit inverter, which assumes the class-E high frequency resonant inverter of conventional current-fed type, flows in the form of the resultant current flowing through each constant current reactor($L_{d1}$, $L_{d2}$). The circuit analysis of proposed inverter is generally described by adopting the normalized parameters and the evaluation of its operating characteristics are conducted by using the parameters such as the ratio of switching and resonant frequency(${\mu}$), coupling coefficient(k) and so on. An example of procedure for circuit design based on the characteristic values obtained from the theoretical analysis is presented. To confirm the validity of the theoretical analysis, the experimental results are also presented. In the future, the proposed inverter shows it can be practically used as power supply system for induction heating application, DC-DC converter etc.

• Journal of Power Electronics
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• 제17권1호
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• pp.31-40
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• 2017

A novel voltage-fed single-stage power factor correction (PFC) full-bridge converter based on asymmetric phase-shifted control for battery chargers is proposed in this paper. The attractive feature of the proposed converter is that it can operate in a wide output voltage range without an output low-frequency ripple, which is indispensable in battery charger applications. Meanwhile, the converter can maintain a high power factor and a controllable dc bus voltage over a wide output voltage range. In this paper, the realization of PFC and the operation principle of asymmetric phase-shifted control are given. A small-signal analysis of the proposed single-stage power factor correction (PFC) full-bridge converter is performed. Experimental results obtained from a 1kW experimental prototype are given to validate the feasibility of the proposed converter. The PF is higher than 0.97 over the entire output voltage range with the proposed control strategy.

• 전력전자학회논문지
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• 제8권6호
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• pp.543-550
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• 2003

본 논문에서는 2대의 다이오드 정류기에 부스트 컨버터를 이용하여 전류의 파형을 능동적으로 만들어 정현파의 입력전류를 얻는 새로운 방식의 고조파 저감방식을 제안한다. 제안한 방식으로 고역률의 전원 품질을 얻을 수 있으며 입력측의 변동에 대한 출력전압의 조정도 가능하다. 또한 저감된 용량을 갖는 3상 오토트랜스포머의 사용으로 기존의 $\Delta$-Y 변압기에 비해 KVA정격이 75% 절감되며 상간변압기도 필요 없다. 본 방식을 소형화와 고품질의 전원이 요구되는 통신용 정류기등에 적용하면 효과적이다. 제안한 방식의 동작원리, 제어 및 설계방법을 기술하고 1.5KW급 시작품으로부터의 실험결과를 제시한다.

• 전기학회논문지
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• 제66권3호
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• pp.593-598
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• 2017

Induction generator is always required reactive power in order to generate a rotating magnetic field as an inductive load. The reactive power must be continuously supplied to the induction generator as well as load of distribution system from the power supply side. So the power factor of the power supply side during the induction generation operation is low. Condenser is installed in order to raise the low power factor of the induction generator. Switching transients occurs when the power supply of the capacitor is turned on in order to ensure the low power factor. When using the reactor in series with the capacitor in order to reduce the influence of switching transient, it can affect the reactive power by the condenser voltage rises. In this study, we analyzed the operating characteristics for power and power factor of induction generator in accordance with the presence or absence of the application of the serial reactors for switching transients reduction of the condenser and the condenser for power factor correction.