• Journal of Power Electronics
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• v.19 no.1
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• pp.278-287
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• 2019

In this study, a zero-crossing spike current issue in a totem-pole bridgeless power factor correction (PFC) converter is comprehensively investigated for the first time. Spike current occurs when input voltage crosses zero, becomes a noise source, and causes severe common mode emission issues. A generation mechanism for electromagnetic interference (EMI) is presented to investigate the EMI problem caused by zero-crossing issue, and a noise spectrum due to this issue is predicted by a theoretical analysis based on the Fourier coefficient of an approximate spike current waveform. Furthermore, a noise reduction method is proposed and then improved to reduce the spike current. Experimental measurements are implemented on a GaN-based totem-pole bridgeless PFC converter, and the spike current can be effectively suppressed through the proposed method. Furthermore, the noise spectrums measured without and with the reduced zero-crossing spike current are compared. Experimental results validate the analysis of the noise spectrum caused by the zero-crossing spike current issue.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.2
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• pp.85-91
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• 2022

This study proposes a high efficiency bridgeless Power Factor Correction (PFC) converter with improved common mode noise characteristics. Conventional PFC has limitations due to low efficiency and enlarged heat sink from considerable conduction loss of bridge diode. By applying a Common Mode (CM) coupled inductor, the proposed bridgeless PFC converter generates less conduction loss as only a small magnetizing current of the CM coupled inductor flows through the input diode, thereby reducing or removing heat sink. The input diode is alternately conducted every half cycle of 60 Hz AC input voltage while a negative node of AC input voltage is always connected to the ground, thus improving common mode noise characteristics. With the aim to improve switching loss and reverse recovery of output diode, the proposed circuit employs Critical Conduction Mode (CrM) operation and it features a simple Zero Current Detection (ZCD) circuit for the CrM. In addition, the input current sensing is possible with the shunt resistor instead of the expensive current sensor. Experimental results through 480 W prototype are presented to verify the validity of the proposed circuit.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2310-2318
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• 2018

Critical conduction mode (CRM) operation is more efficient than continuous conduction mode (CCM) operation at low power levels because of the valley switching of switches and elimination of the reverse recovery losses of boost diodes. When using a sensorless digital control method, an error occurs between the actual and the estimated current. Because of the error, it operates as CCM or discontinuous conduction mode (DCM) during CRM operation and also has an adverse effect on THD of input current. In this paper, a current sensorless technique is presented in an inverter system using a bridgeless boosted power factor correction converter, and a compensation method is proposed to reduce CRM calculation error. The validity of the proposed method is verified by simulation and experiment.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.151-152
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• 2012

본 논문은 전기자동차의 탑재형 충전기 (OBC, On-Board Charger)에 적용 가능한 고효율 역률개선회로 (PFC, Power Factor Correction Circuit)들의 손실을 분석한다. 평균전류모드제어를 이용하여 conventional boost PFC, interleaved boost PFC, semi-bridgeless PFC, totem pole PFC, seudo totem pole PFC, back-to-back bridgeless PFC, interleaved bridgeless PFC 등 7개의 토폴로지를 3.3kW OBC 기반으로 설계하고, 각 토폴로지의 손실을 수식과 PSIM의 thermal module을 이용하여 분석한다. 분석한 결과를 토대로 제시한 토폴로지들의 효율 및 성능을 비교한다.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.359-360
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• 2010

최근 에너지의 근원이 되는 원유가의 급등으로 인해 에너지 소비에 대한 국내외적인 관심이 증폭되어 에너지를 소비하는 측의 효율개선에 대한 요구가 급등하고 있으며 전력변환기 시장에서도 효율이 전력변환기의 사용자의 선택기준이 될 정도로 매우 강력한 실정이다. 본 논문에서는 DSP(TMS320F28035)를 이용한 2kW급 고효율 Bridgeless PFC Converter를 제안한다. 제안된 Converter를 실험을 통해 고효율과 고전력밀도의 기능을 검증하였다.

• Journal of Power Electronics
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• v.12 no.2
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• pp.268-275
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• 2012

Based on the standards that limit the harmonic pollution of electronic systems, the use of PFC converters is mandatory. In this paper, a new resonant bridgeless PFC converter is introduced. By eliminating the input bridge diodes, the efficiency is improved. Moreover, soft switching conditions for all of the semiconductor elements are achieved without adding any extra switches. As a result, high efficiency is attained. The proposed converter is analyzed and the theoretical and simulation results of the proposed converter are presented. In order to verify the validity of the analysis, a 40 w prototype converter is implemented and experimental results are presented. The experimental results show that high efficiency is attained while achieving a high power factor.

• Journal of Power Electronics
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• v.13 no.1
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• pp.40-50
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• 2013

In this paper, a new zero-voltage-switching, high power-factor, bridgeless rectifier is introduced. In this topology, an auxiliary circuit provides soft switching for all of the power semiconductor devices. Thus the switching losses are reduced and the highest efficiency can be achieved. The proposed converter has been analyzed and a design procedure has been introduced. The control circuit for the converter has also been developed. Based on the given approach, a 250 W, 400 Vdc prototype converters has been designed at 100 kHz for universal input voltage (90-264 Vrms) applications. A maximum efficiency of 94.6% and a power factor correction over 0.99 has been achieved. The simulation and experimental results confirm the design procedure and highlight the advantages of the proposed topology.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.81-83
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• 2018

본 논문에서는 inductive power transfer (IPT) 시스템 2차측 semi-bridgeless 정류기에 pulse density modulation (PDM) 제어를 적용하기 위한 시스템 설계 방안을 제안한다. LCCL-S 토폴로지를 사용한 IPT 시스템에 PDM 제어를 적용하였을 때 나타나는 출력특성을 기존의 SS 토폴로지를 사용한 시스템의 출력특성과 비교 분석한다. 분석 결과를 바탕으로, 실제 전기자동차 배터리 충전사양을 고려하여 3.3 kW 급 IPT 시스템을 설계하고 설계 결과를 시뮬레이션을 통해 검증한다.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.77-79
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• 2018

본 논문에서는 inductive power transfer (IPT) 시스템 2차측 semi-bridgeless 정류기에 pulse density modulation (PDM) 제어를 적용하였을 때 1차측에 나타나는 영향을 최소화하기 위한 공진 네트워크 설계 방안을 제안한다. PDM 제어를 적용하였을 때 2차측 전류 리플이 증가하는 문제를 해결하기 위해 2차측 수신 인덕턴스를 증가시킴으로써 전류 리플을 저감하여 1차측 영향을 최소화한다. 이를 위해 적절한 설계 조건을 구하는 방안에 대하여 제시하고, 방안의 적용에 따른 1차측 영향을 시뮬레이션을 통해 분석한다.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.263-264
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• 2016

일반적으로 HID 램프용 안정기에는 디지털 제어기를 사용하지 않지만 디지털 제어로 구현하는 경우 여러 가지 이점이 있다. 따라서 본 논문에서는 DSP를 기반으로 Bridgeless CRM PFC Converter 제어를 디지털로 구현 할 것을 제안하였다. 이때 인덕터 전류 검출을 하지 않기 위하여 DSP 연산에 의해 계산된 온, 오프 시간으로 동작하도록 하였으며, 과도상태 시 출력 전압에 따른 주파수 제한 방법을 통해 안정적인 구동이 가능하도록 하였다. 제안한 방식은 시뮬레이션을 통해 검증하였다.