• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.1002-1007
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• 2003

A new driving circuit for the SPSS (Single-Pulse Soft-Switching) PFC converter is proposed. The switching device of a SPSS converter switches once In every half cycle of an AC commercial power source. Therefore, it can be solved many problems caused by the high frequency operation. The proposed SPSS converter achieves the soft-switching operation and the EMI noise can be reduced. The resonant capacitor voltage supplies to the resonant inductor even if the input AC voltage is the vicinity of zero cross voltage. Then, the power factor and input current waveform can be improved without delay time. A new driving circuit achieves the operation of SPSS converter by one switching drive circuit. The proposed converter can be satisfied the IEC standard sufficiently.

• Journal of electromagnetic engineering and science
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• 제11권3호
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• pp.161-165
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• 2011

In this paper, a high-efficiency DC-AC converter is used for wireless energy transmission. The DC-AC convertter is implemented by combining the oscillator and power amplifier. Given that the conversion efficiency of a DC-AC converter is strongly affected by the efficiency of the power amplifier, a high-efficiency power amplifier is implemented using a class-E amplifier structure. Also, because of the low output power of the oscillator connected to the input stage of the power amplifier, a high-gain two-stage power amplifier using a drive amplifier is used to realize a high-output power DC-AC converter. The high-efficiency DC-AC converter is realized by connecting the oscillator to the input stage of the high-gain high-efficiency two-stage class-E power amplifier. The output power and the conversion efficiency of the DC-AC converter are 40.83 dBm and 87.32 %, respectively, at an operation frequency of 13.56 MHz.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.919-926
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• 2021

In this paper, a study was conducted on the miniaturization of an e-Mobility battery charger module using GaN-FET. GaN-FET is one of the types of WBG devices, and it is a device that exceeds the performance of existing Si power semiconductors. In particular, GaN-FET has the advantage of small packaging size and high switching frequency operation, which is advantageous for miniaturization of power converters. Therefore, a bidirectional DC/DC converter module for e-mobility charging using GaN-FET was developed. To apply to the converter to be developed, analysis is performed on the characteristics of GaN-FET, and after manufacturing a prototype of a bidirectional DC/DC converter module, the efficiency and temperature data of the power converter are analyzed to verify its feasibility.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2065-2069
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• 2014

The DAC-7512E is a 12-bit digital to analog converter that is low power and a single package with internal buffers. The DAC-7512E takes up minimal PCB area for applications of space power electronics design. The spacecraft mass is a crucial point considering spacecraft launch into space. Therefore, we have performed a TID test for the DAC-7512E 12-bit serial input digital to analog converter to reduce the spacecraft mass by using a low-level Gamma-ray irradiator with $Co^{60}$ gamma-ray sources. The irradiation with $Co^{60}$ gamma-rays was carried out at doses from 0 krad to 100 krad to check the error status of the device in terms of current, voltage and bit error status during conversion. The DAC-7512E 12-bit serial digital to analog converter should work properly from 0 krad to 30 krad without any error.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.385-387
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• 1996

A novel two stage soft-switching ac-to-dc convener with power factor correction is proposed. The proposed convener provides zero-voltage-switching (ZVS) condition to main switch of boost pre-regulator without auxiliary switch. Comparing to the conventional two stage approach(ZVS-PWM boost rectifier followed by off-line ZVS dc-dc step down converter), the proposed approach is simple and reducing EMI noise problem. A new simple DC-linked energy feedback circuit provides zero-voltage-switching condition to boost pre-regulator without imposing additional voltage and current stresses and loss of PWM capability. Operational principle, analysis, control of the proposed converter together with the simulation results of 1KW prototype are presented.

• 전력전자학회논문지
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• 제21권2호
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• pp.175-181
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• 2016

In the conventional E-bike, a 42 V/10 A Li-ion battery drives a 24 V/10 A BLDC motor via a 6-switch PWM DC/AC inverter. The major problems of the conventional battery-fed motor drive systems are listed as follows. To charge the battery, an external battery charger (adapter) is required, which degrades the portability of E-bike users. In addition, given the high-frequency operation of the motor drive inverter, the switching losses are significant, which degrades the whole power efficiency. High-voltage batteries (42 V) require a complex battery management system (BMS), which degrades the reliability of the battery pack. In this paper, an embedded boost-converter battery charger for E-bikes is proposed. The variable output boost converter, which converts 16.8 V battery voltage to the required variable voltage of the inverter input, can use a low-voltage battery and thus improve the reliability of batteries. By varying the inverter input voltage via boost converter, a DC link voltage control method can be applied to reduce the switching frequency of the inverter, which improves the whole power efficiency. Given that the function of a flyback charger is integrated in the proposed boost converter, the portability of the E-bike user can be maximized by excluding an external adapter. The validity of the proposed circuit will be confirmed by operation mode analysis and simulation. Moreover, experimental results of integrative charger using Li-ion battery and 200 W motor test will be showed with a prototype sample as well.

• 한국융합학회논문지
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• 제9권3호
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• pp.39-44
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• 2018

논문은 E-Mobility용 전력변환기의 고장 진단을 위해 차량 상태의 모니터링 기술을 IoT 기술을 접목하여 스마트폰으로 연동하여 운용하는 것에 대한 것이다. 중국에서는 EV 규제를 실시하여 기술의 발전과 전기자동차에 대한 시장 변화를 유도하고 있다. 이러한 추세에 맞게 E-Mobility도 적합한 모니터링 기술을 연구해야 한다. 기존 자동차에서 적용하는 OBD-II를 이용한 방법은 유무선 통신 방법이다. E-Mobility에 적용하기 위해서는 추가의 인터페이스 및 통신연동이 필요하다. 본 논문에서는 기존 기술과 IoT를 접목시켜 E-Mobility용 전력변환기의 상태정보를 모니터링 하는 기술을 제안하였다. 이 기술을 통해서 기존 네트워크 프로토콜 및 하드웨어 인터페이스를 간소화 하였고, 사용자가 쉽게 모니터링 할 수 있도록 E-Mobility용 전력변환기와 스마트폰의 연동이 가능함을 확인하였다. 그리고 기능 측면에서 고부가가치 제품 설계가 되도록 연구를 수행하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.287-291
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• 2002

This paper presents active-clamp class-E high frequency resonant inverter with single-stage. The proposed circuit is integrated active-clamp class-E circuit to boost converter with the function of power factor correction. Boost converter is operated in positive and negative half cycle respectively at line frequency(60Hz), Such a operating in discontinuous conduction mode(DCM) of boost converter performs high power factor. By adding active-clamp circuit in class-E inverter, main switch of inverter part is operated not only ZVS(Zero Voltage Switch) but also reduced the switching voltage stress of main switch. This paper shows that simulation result using Psim 4.1 prove the validity of theoretical analysis. 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.

• 한국시뮬레이션학회논문지
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• 제10권3호
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• pp.1-14
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• 2001

A hybrid system is defined as a mixture of continuous systems and discrete event systems. This paper first proposes a framework for hybrid systems modeling, called Hybrid Discrete Event System Specification (HDEVS) formalism. It then presents a method for simulators interoperation in which a continuous system simulator and a discrete event simulator are executed together in a cooperative manner. The formalism can specify a hybrid system in a way that a continuos system and a discrete event system are separately modeled by their own specification formalisms with a support of well-defined interface. We call such interface an A/E converter for analog-to- event conversion and an E/A converter for event-to-analog conversion. Simulators interoperation is based on the concept of pre-simulation in which simulation time for a continuous simulator is advanced in accordance with a discrete event simulator.

• 한국전자파학회논문지
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• 제22권8호
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• pp.805-808
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• 2011

본 논문에서는 220 V의 AC 전원을 공급받아 13.56 MHz의 RF 신호를 출력하는 고효율, 고출력 Class E 전력송신기를 설계하였다. 송신기는 AC-DC 변환기와 class E 전력 증폭기로 구성된다. 설계된 AC-DC 변환기는 220V/60 Hz의 가정용 전원을 공급 받아서 약 290 V의 DC 전압을 출력한다. 이때, AC-DC 변환기는 98.03 %의 매우 높은 변환 효율을 가진다. 변환 효율을 최대로 하기 위하여 별도의 DC-DC 변환기를 사용하지 않고, AC-DC 변환기의 출력 전압을 주 전력 증폭기의 드레인 바이어스 전압으로 사용하였다. 또한, class E 전력 증폭기의 전력손실을 최소화하기 위해 high-Q 인덕터를 제작하였다. 측정 결과, 13.56 MHz에서 동작하는 class E 전력 증폭기는 최대 출력 전력 323.6 Watt에서 84.2 %의 PAE(Power-Added Efficiency)를 가진다. AC-DC 변환기를 포함한 class E 전력 송신기는 323.6 Watt에서 82.87 %의 매우 높은 효율 특성을 나타낸다.