• 조명전기설비학회논문지
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• 제19권7호
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• pp.45-52
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• 2005

본 논문은 전류불연속 제어에 의한 고역률, 고효율로 동작되는 승압형 AC-DC 컨버터에 대해 연구된다. 전류불 연속 제어 컨버터는 제어회로 구성이 간단하고 구성소자의 수를 줄일 수 있는 장점을 가진다. 제안된 컨버터의 입력전류는 듀티율 일정제어에 의한 교류 입력전압의 크기에 비례된 불연속적인 정현파 형태로 된다. 그 결과 입력역률은 거의 단위역률로 주어지며 듀티율 일정제어에 의해 제어기법이 간단하다. 또한 제안된 컨버터의 스위칭 소자들은 부분공진 기법에 의해 소프트 스위칭 동작으로 되어 스위칭 손실이 매우 낮으며 컨버터의 효율을 증대시킨다. 부분공진 회로부는 승압용으로 사용된 인덕터와 무손실 스너버 커패시터에 의해 설계되어 컨버터의 회로 토폴로지가 간단하다. 제안된 컨버터는 컴퓨터 시뮬레이션과 실험결과에 의해 그 타당성이 입증된다.

• 전기학회논문지
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• 제58권7호
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• pp.1349-1355
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• 2009

This paper is studied on a novel power factor correction (PFC) AC-DC converter of high efficiency by soft switching technique. The input current waveform in the proposed converter is got to be a sinusoidal form composed of many a discontinuous pulse in proportion to the magnitude of a ac input voltage under the constant switching frequency. Therefore, the input power factor is nearly unity and the control method is simple. The proposed converter adding an electric isolation operates with a discontinuous current mode (DCM) of the reactor in order to obtain some merits of simpler control, such as fixed switching frequency, without synchronization control circuit used in continuous current mode (CCM). To achieve the soft switching (ZCS or ZVS) of control devices, the converter is constructed with a new loss-less snubber for a partial resonant circuit. It is that the switching losses are very low and the efficiency of the converter is high, Particularly, the stored energy in a loss-less snubber capacitor recovers into input side and increases input current from a resonant operation. The result is that the input power factor of the proposed converter is higher than that of a conventional PFC converter. This paper deals mainly with the circuit operations, theoretical, simulated and experimental results of the proposed PFC AC-DC converter in comparison with a conventional PFC AC-DC converter.

• 대한전자공학회논문지
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• 제11권4호
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• pp.30-38
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• 1974

Moment법에 의하여 임의형상으로 굴곡된 선형 안테나의 전류분포와 임의의 급전점에 대한 인력임피던스를 구하는 방법을 제시하고 그 이론을 정강파형으로 굴곡된 안테나에 적용하여 전류분포와 입력임피던스를 구했다. 실험결과가 그의 타당성을 뒷 받침하고 있어 다른 형태의 안테나 문제를 분석하는데 널리 이용 될 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.2210-2212
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• 1997

A sensorless input current controller for three phase PWM converter is proposed. A merit of this controller is that sinusoidal input line current, unity power factor, and ripple-free DC voltage can be achieved with low-cost. The paper describes the proposed control strategy and its implementation. Simulation result for the proposed controller is compared with that of the sensor based version.

• 수산해양기술연구
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• 제56권1호
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• pp.71-81
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• 2020

This paper proposes a possibility of using active front-end rectifier with the SVPWM method for induction motor speed control, which is applicable to small electric propulsion boats. The proposed method can produce a more precise sinusoidal input current waveform and a higher power factor than conventional methods. Its speed, torque, input current, DC voltage, and load current control performance are similar to or better than those of conventional methods. Through computer simulations using the PSIM program, the validity of the proposed method was verified by comparing and analyzing the characteristics of the conventional methods and the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.999-1001
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• 1992

This paper describes the voltage type PWM converter. Input AC current is to be sinusoidal and AC input voltage is determined by controlling the phase of the source and converter properly. By corresponding the phase of input voltage to that of base current, DC constant voltage Is to be output with high power factor driving. Also it is possible to be leading or lagging power factor driving. Optimum driving is performed by controlling the current instantaneously in the steady state or transient state.

• 대한전자공학회논문지
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• 제9권5호
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• pp.12-18
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• 1972

정현 신호 및 zero 평균 정상 정규 잡음의 협대역파 신호를 갖는 n차 반파 zero기억형 비선형 장치의 출력 SN 비 및 m차 고조파 발생의 관계를 밝혔다. 최대 출력 SN비는 소 신호 입력에서 m=n=2 이었으며 대 신호 입력에선 항시 n=2이었다.

• 전자공학회논문지A
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• 제31A권2호
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• pp.18-25
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• 1994

In this papaer, the input impedance of the rectangular microstrip patch antennas with the multilayered structure is analysed by using the moment method technique in the spectral domain. The analysis is carried out for two different feeding structures : directfeeding structure and electromagnetic-feeding structure. In order to obtain the accurate input impedance, the current distribution on the microstrip feed line is modeled by the quasi-TEM travelling wave and the PWS(piecewise sinusoidal) mode. The input impedances of the designed microstrip antennas are measured and compared with the calculation. which shows a good agreement.

• Journal of Electrical Engineering and Technology
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• 제5권3호
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• pp.477-483
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• 2010

This paper is studied on a novel buck-boost isolated converter for high efficiency and high power factor. The switching devices in the proposed converter are operated by soft switching technique using a new quasi-resonant circuit, and are driven with discontinuous conduction mode (DCM) according to pulse width modulation (PWM). The quasi-resonant circuit makes use of a step up-down inductor and a loss-less snubber capacitor. The proposed converter with DCM also simplifies the requirement of control circuit and reduces a number of control components. The input ac current waveform in the proposed converter becomes a quasi sinusoidal waveform in proportion to the magnitude of input ac voltage under constant switching frequency. As a result, it is obtained by the proposed converter that the switching power losses are low, the efficiency of the converter is high, and the input power factor is nearly unity. The validity of analytical results is confirmed by some simulation results on computer and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1242-1244
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• 2000

A new control method using average comparison strategy have been proposed in this paper. This control method realizes sinusoidal input and output current. unity input displacement factor regardless of load power factor. Moreover, compensation of the asymmetrical and/or harmonic containing input voltage is automatically realized, and calculation time of control function is reduced.