• 한국전자파학회논문지
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• 제26권9호
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• pp.798-805
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• 2015

본 논문에서는 랜덤 수 생성 회로를 통해 Relaxation Oscillator의 주파수를 불규칙하게 변환하여 EMI Noise를 최소화하는 방법을 제시한다. 또한, DC-DC Converter에 이 기법이 적용되었을 때의 효과와 이 결과가 RF Receiver system에 미치는 효과를 Noise 측면에서 연구하였다. 제안하는 Relaxation Oscillator 출력 중심주파수는 7.9 MHz이고, 온도보상기법을 적용하여 온도변화에 따라 주파수가 보상되도록 설계하였다. 이 칩은 $0.18{\mu}m$ 공정으로 설계하였고, 칩의 면적은 $220{\mu}m{\times}280{\mu}m$이다. 전류 소모는 공급전압인 1.8 V에서 $500{\mu}A$이다.

• Journal of Power Electronics
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• 제11권5호
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• pp.767-777
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• 2011

Power electronic systems such as switching power supplies are accounted as noise sources for other sensitive circuits. EMI caused by power converters can disturb the normal operation of the converter and other adjacent systems. Major research is concentrated on EMI mitigation for power converters in which the main concern is compliance with EMC standards to ensure proper operation of converters and nearby systems. This paper reviews EMI reduction techniques related to switching power converters with emphasis on the conducted EMI. A comprehensive review of significant research works is performed and various methods are thoroughly discussed and compared. Also, a classification of methods is presented. Moreover, converter prototypes are realized which contain several EMI mitigation techniques and their effects are presented via experimental results.

• 한국정보전자통신기술학회논문지
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• 제16권2호
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• pp.104-108
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• 2023

최근 전기 차 시장의 확대로 인해 성능 및 안정성 문제를 보완할 친환경적인 전기 차 시장이 매우 커지고 있다. 전기 차의 화재 등 여러 안전 문제를 일으키는 전장 부품의 연동으로 인한 EMI 문제는 매번 대두되어 지고 있다. 다양한 기술들을 결합하여 최적의 충전효율을 달성하고 무선 충전 컨트롤 모듈에서 발생하는 EMI 잡음을 줄이기 위해 노력하고 있다. 본 논문은 전기자동차의 중요한 부품 중 하나인 무선충전컨트롤 모듈의 EMI 잡음 중 방사성 잡음 저감 기술을 설계하여 실험을 하였다. 무선 충전 컨트롤 모듈에서 발생하는 EMI 문제를 분석하기 위해 Ansys 시뮬레이션 툴 내 Python 기반 스크립트 기능을 활용하여 치명적인 요인에 대한 축적된 시험 데이터를 학습시켜 강화 학습을 통한 최적화 설계 기술을 적용하여 최적화된 무선충전컨트롤 모듈은 일반적인 무선충전 컨트롤 모듈 대비 25dBu V/m의 EMI 잡음 개선 효과를 보였다. 이러한 결과는 전기 자동차에서 더 안정적이고 신뢰성 높은 무선 충전 기능의 개발에 기여할 뿐만 아니라, 이를 통해 전기자동차의 사용성과 효율성을 높이며 환경친환적인 대안으로 자리 잡을 수 있게 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 학술대회 논문집 전문대학교육위원
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• pp.154-158
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• 2006

The switching-mode power converter has been widely used because of its features of high efficiency and small weight and size. These features are brought by the ON-OFF operation of semiconductor switching devices. However, this switching operation causes the surge and EMI(Electromagnetic Interference) which deteriorate the reliability of the converter themselves and entire electronic systems. This problem on the surge and noise is one of the most serious difficulties in AC-to-DC converter. Random Pulse Width Modulation (RPWM) is peformed by adding a random perturbation to switching instant while output-voltage regulation of converter is performed. RPWM method for reducing conducted EMI in single switch three phase discontinuous conduction mode boost converter is presented. The more white noise is injected, the more conducted EMI is reduced. But output-voltage is not sufficiently regulated. This is the reason why carrier frequency selection topology is proposed. In the case of carrier frequency selection, output-voltage of steady state and transient state is fully regulated. A RPWM control method was proposed in order to smooth the switching noise spectrum and reduce it's level. Experimental results are verified by converter operating at 300v/1kW with $5%{\sim}30%$ white noise input. Spectrum analysis is performed on the Phase current and the CM noise voltage. The former is measured with Current Probe and the latter is achieved with LISN, which are connected to the spectrum analyzer respectively.

• Journal of electromagnetic engineering and science
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• 제6권4호
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• pp.197-202
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• 2006

This paper presents a study on the differential signaling for the rectangular power-bus structure. The full-wave modal analysis method analyzes how the differential-signaling can lower the power-bus resonance noise levels. The methodology is validated by the use of the FDTD method and reference measurements.

• 전기학회논문지P
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• 제51권3호
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• pp.120-125
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• 2002

The switching-mode power converter has been widely used because of its features of high efficiency and small weight and size. These features are brought by the ON-OFF operation of semiconductor switching devices. However, this switching operation causes the surge and EMI(Electromagnetic Interference) which deteriorate the reliability of the converter themselves and entire electronic systems. This problem on the surge and noise is one of the most serious difficulties in AC-to-DC converter. In the switching-mode power converter, the output voltage is generally controlled by varying the duty ratio of main switch. When a converter operates in steady state, duty ratio of the converter is kept constant. So the power of switching noise is concentrated in specific frequencies. Generally, to reduce the EMI and improve the immunity of converter system, the switching frequency of converter needs to be properly modulated during a rectified line period instead of being kept constant. Random Pulse Width Modulation (RPWM) is performed by adding a random perturbation to switching instant while output-voltage regulation of converter is performed. RPWM method for reducing conducted EMI in single switch three phase discontinuous conduction mode boost converter is presented. The more white noise is injected, the more conducted EMI is reduced. But output-voltage is not sufficiently regulated. This is the reason why carrier frequency selection topology is proposed. In the case of carrier frequency selection, output-voltage of steady state and transient state is fully regulated. A RPWM control method was proposed in order to smooth the switching noise spectrum and reduce it's level. Experimental results are verified by converter operating at 300V/1kW with 5%~30% white noise input. Spectrum analysis is performed on the Phase current and the CM noise voltage. The former is measured with Current Probe and the latter is achieved with LISN, which are connected to the spectrum analyzer respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 F
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• pp.2159-2161
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• 1997

This paper presents the investigations and the reduction methods for EMI in the Elevator(E/L) system. In the large capacity E/L. Power factor controlled IGBT converter is used, so that the conducted EMI level is mostly determined by a high frequency input current. We suggest the low cost EMI countermearsure for E/L system using by a LCL filter ed a low cost noise filter.

• 전력전자학회논문지
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• 제8권5호
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• pp.455-462
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• 2003

스위칭 PFC 컨버터는 전력의 질을 향상시킬 뿐 아니라 최대 효율을 얻기 위해 널리 사용된다. 하지만, 스위칭 PFC 컨버터는 심각한 EMI 문제를 발생시킨다. 본 논문에서는 이 문제를 해결하기 위해서 APW 기법과 RPWM 기법을 PFC Boost 컨버터에 적용하여 우수한 결과를 얻었다. 시뮬레이션과 실험 결과를 통해서 에어컨 시스템에서의 개선된 고조파와 저감된 EMI 효과를 보여준다.

• 항공우주기술
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• 제5권2호
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• pp.67-76
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• 2006

본 논문에서는 위성 시스템 개발을 위하여 요구되고 있는 전도성 전자파 환경에 대한 규격을 정의하기 위한 전도성 노이즈 해석방법과 전도성 감응특성을 검증하기 위한 시험 평가 방법에 대해서 나타냈다. 전도성 전자파환경을 정의하는데 주된 요소는 전력변환 회 로의 스위칭 노이즈와 공통 임피던스의 결합특성을 생각할 수 있다. 이러한 전도성 환경에 대한 규격의 정의 및 이를 통제하기 위해서는 시스템 및 유닛 설계단계에서 EMC 해석을 통하여 시스템 또는 유닛레벨에 대한 노이즈 특성을 예측하고, 제작단계에서 이에 따른 EMC 대책을 적용하게 된다. 시스템 전자파환경은 신중하게 통제하고 EMC 안정성 마진을 충분히 고려하여 설계되어야 하며, EMI 특성은 전체 개발과정을 통하여 충분히 검증되어 야 한다.

• 전기학회논문지
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• 제58권7호
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• pp.1336-1341
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• 2009

In this paper, an EMI reduction effects using an EMC chamber is described and reduction methods is proposed. In the case of general electronic components a working frequency is low. But in this paper the vehicle cluster works 75MHz in the main clock frequency, becoming weak by noise because of being attached in TFT LCD. As the outer case installed in the vehicle is made up of plastic materials, the noise is radiated if not protecting noise in the PCB itself. Therefore, This paper will explain the theoretical basis and propriety with respect to the discussion and need about the guide for PCB design considering EMC, through the reduction of PCB noise.