• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.147-150
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• 2002

HPSL(High Pressure Sodium lamp)have attracted much attention in recent years, because they offer high luminous efficiency and very long life. Recently, AC-DC converters have been widely as power factor improvement circuits in the power conversion equipment An application of the ZVT-PWM(Zero Voltage Transition Pulse Width Modulation) boost converter, which has great advantage on miniaturization and high power density, to the power factor improvement circuit of the HPSL inverter are described to identify the power factor correction characteristics of the inverter. In this paper the series-parallel resonant inverter(electronic ballast) for driving a HPS lamp is discussed. Finally, a power factor corrector is cascaded in front of the electronic ballast. Consequently, a high power factor above 0.99 and low THD on the line current can be achieved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1339-1341
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• 2000

This paper presents a new PWM DC/DC converter with multi-output using single secondary winding, which has two output characteristics of the isolation and non-isolation simultaneously. The proposed converter topology is consisted of the only one switch and single secondary winding. The proposed converter, therefore, has advantages not only low cost but also high power density. Operating principal of the proposed converter topology with conventional ZVT (Zero-Voltage-Transition) is illustrated in detail and the validity of the converter is verified with several interesting simulation results.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.33-34
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• 2012

본 논문에서는 도통 손실 저감을 위한 ZVT(Zero voltage transition) 부스트 컨버터를 제안하였다. 제안한 부스트 컨버터는 일반 부스트 컨버터에 보조 스위치, 공진 인덕터 그리고 공진 커패시터를 추가함으로써 ZVS와 ZCS를 달성하였다. 이를 통하여 스위치에 전압 스트레스와 전류 스트레스를 줄였기 때문에 스위칭 손실이 저감되고 컨버터 효율이 향상된다. 제안된 회로는 모드 분석과 시뮬레이션을 통하여 타당성을 검증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.535-538
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• 1994

In this paper, an isolated ZVS-PWM boost converter is proposed for single stage line conversion. For power factor correction, we used the half bridge topology at the primary side of isolation transformer permitting switching devices to operate under ZVS by using circuit parastics and operating at a fixed duty ratio near 50%. Thus the relatively continuous input current distortion and small size input filter are also achievable. The ZVS-PWM boost operation of the proposed converter can be achieved by using the boost inductor $L_f$, main switch $Q_3$, and simple auxiliary circuit at the secondary side of isolation transformer. The secondary side circuit differ from a conventional PWM boost converter by introduction a simple auxiliary circuit. The auxiliary circuit is actived only during a short switching transition time to create the ZVS condition for the main switch as that of the ZVT-PWM boost converter. With a single stage, it is possible to achieve a sinusoidal line current at unity power factor as well as the isolated 48V DC output. Comparing to the two stage schemes, overall effiency of the proposed converter is highly improved due to the effective ZVS of all devices as well as single stage power conversion. Thus, it can be operated at high switching frequency allowing use of small size input filter. Minimum voltage and current stress make it high power application possible.