• 산업기술연구
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• 제34권
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• pp.71-78
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• 2014

Recently, using the electronic devices was increased with semiconductor developments. So, the EMI(Electromagnetic interference) problem become to important issue for coexistence with each electronic devices. The EMI is caused by switching operation from the power switches as the FET and the transistor in power conversion devices. In this paper, the hybrid EMI filter that composed with active components and passive components was described. The EMI filter is applied to the 160 watts LED driver experimentally verify the performance. The hybrid EMI filter is compared with non-filter, only passive filter and only active filter. The proposed EMI filter attenuated CM noise more than traditional passive filter.

• 조명전기설비학회논문지
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• 제29권6호
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• pp.78-89
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• 2015

Conventional EMI filters have tried to use an active EMI filter as a series by the series connection of two EMI filters for CM and DM noise. However, the proposed filter is formed into one circuit by using the active EMI filter which is able to filter CM and DM noise components together. As a result, the active EMI filter showed the outstanding quality in mass and volume under 50% and electric characteristics have been compared to the passive EMI filter in approximately 150kHz~10MHz. Furthermore, the proposed circuit has simple circuit components by comparing with the series EMI filters, and electrical characteristics are similar. The noise have been attenuated to maximum 20dBuV.

• 조명전기설비학회논문지
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• 제29권2호
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• pp.62-68
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• 2015

Recently, LED is being used as various applications such as home lightings, work lightings and so on. EMI noise generated from LED driver have become a problem according to increase the use of LED. In this paper, Active EMI filter composed active and passive components is discribed as a method of solving a problem of EMI. The proposed filter is applied to the 160W LED load to verify performance experimentally. To compare the performance, We did an experiment using the proposed filter and the passive filter on the same 160W LED load and Driver System. As a result, The proposed Active EMI filter attenuated Conduction EMI noise better than any existing passive filter.

• Journal of Power Electronics
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• 제14권4호
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• pp.806-813
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• 2014

Planar electromagnetic interference (EMI) filters are widely used to restrain the conducted EMI of switching power supplies. Such filters are characterized by small size, low parasitic parameters, and better high-frequency performance than the passive discrete EMI filter. However, EMI filter performance cannot be exactly predicted by using existing methods. Therefore, this paper proposes a method to use scattering parameters (S-parameters) for the measurement of EMI filter performance. A planar EMI filter sample is established. From this sample, the relationship between S-parameters and insertion gain (IG) of EMI filter is derived. To determine the IG under different impedances, the EMI filter is theoretically calculated and practically measured. The differential structure of the near-field coupling model is also deduced, and the IG is calculated under standard impedance conditions. The calculated results and actual measurements are compared to verify the feasibility of the theory.

• 전력전자학회논문지
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• 제9권1호
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• pp.81-87
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• 2004

본 논문에서는 세탁기, 에어컨과 같은 가전기기에 사용되는 인버터 구동 교류 전동기 구동 시스템의 EMI 특성해석 및 필터 설계 방법에 대하여 기술하였다. 먼저, 인버터 구동 교류 전동기 구동 시스템의 전도성 EMI 발생 및 전달 메커니즘에 대하여 분석하였고, 공통 및 차동모드 노이즈 분리 기법을 이용한 EMI 필터의 설계 방법을 제시하였다. 제시된 방법의 타당성을 검증하기 위해 PWM 인버터로 구동되는 유도 전동기 구동 시스템에 대한 실험을 수행하였고 EN55014 EMI 기준을 만족하는 결과를 얻을 수 있었다.

• 전력전자학회논문지
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• 제14권6호
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• pp.440-448
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• 2009

설비용 전원선 EMI 필터(Facility power-line EMI filter)는 컴퓨터 센터와 같이 전자기적인 노이즈에 민감한 장비를 가진 배전 설비로 유입되는 EMI를 차단하기 위해 사용된다. 따라서 전류용량이 크며 특정한 응용분야에서는 MIL-STD 220 기준으로 14kHz~10GHz의 광대역에서 최고 100dB 이상의 삽입 손실(Insertion loss)이 요구된다. 이러한 요구조건을 만족하기 위해서는 광대역의 주파수에서 커패시터, 인덕터 등의 특성 분석과 고차 LC 필터 (High order LC filter) 설계기술이 필요하다. 본 논문에서는 이러한 광대역 설비용 전원선 EMI 필터의 설계에 대하여 기술하였다. 먼저, EMI 필터 설계를 위한 필터의 특징과 구조, 필터의 설계 과정, 필터 설계 방법 등에 대한 연구를 수행하였다. 그리고 필터 구성의 기본 소자인 커패시터와 인덕터의 특성에 대해 분석하였다. 최종적으로 광대역 설비용 전원선 EMI 필터를 설계 및 제작하여 실험을 수행하였으며, 실험 결과의 비교 분석을 통해 연구 결과를 검증하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.97-100
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• 1996

In this paper, 3-terminal EMI filter for communication was studied. EMI filter for communication combining Ferrite bead with 3-terminal capacitor was constructed with T-type. We was able to control resonance frequency with chip capacitor value and attenuation characteristics by Ferrite bead properties.

• Journal of Power Electronics
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• 제12권4호
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• pp.632-642
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• 2012

This paper presents a filter analysis of conducted Electro-Magnetic Interference (EMI) in switching power converters (SPC) based on noise impedances. The EMI characteristics of SPC can be analytically deduced from a circuit theoretical viewpoint. The analytical noise model is investigated to get a full understanding of the EMI mechanism. It is shown that with suitable and justified model, filters pertinent to EMI noise is investigated. The EMI noise is identified by time domain measurements associated with an isolated half-bridge ac-dc converter. Practical filters like LC filter, ${\pi}$ filter and complete EMI filters are investigated. The proposed analysis and results can provide a guideline for improving the effectiveness of filtering schemes in SPC. Experimental results are also included to verify the validity of the proposed method. The results obtained satisfy the Federal Communications Commission (FCC) class A and class B regulations.

• Journal of Power Electronics
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• 제16권3호
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• pp.1200-1208
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• 2016

Planar electromagnetic interference (EMI) filter has significant engineering significance to power electronic system integration and miniaturization. However, the value of differential mode capacitance cannot meet the demand of noise suppression because of the size limit of ceramics. In this case, the EMI filter of novel multilayers is recommended to address this issue. A novel integrated structure of EMI filter based on multilayer ceramic is proposed in this study. The inductance and capacitance of the new structure can be designed separately, which is an advantage in manufacturing. Insertion loss is measured more closely to the actual situation in this study, which is different from the condition where source and load impedances are both 50 Ω. In the process of designing a novel EMI filter, noise impedance is considered. Moreover, the prototype is created and applied to a small switching power supply, which verifies the effectiveness of the developed EMI filter.

• 한국정보통신학회논문지
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• 제5권4호
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• pp.798-806
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• 2001

전자산업 및 전파통신기술의 급속한 발달에 따라 전기, 전자장치의 경량화, 소형화, 저전력화와 더불어 이들은 인위적인 제어가 어려운 자연 현상에 의한 미소한 전자파장해에도 민감하게 감응하여 오동작을 일으키는 사례가 늘고 있다. 본 논문에서는 이에 대한 개선책의 하나로 기존의 EMI 필터보다 150 kHz~30 GHz 대역에서 10 dB~20 dB 감쇠 효과를 더 가지는 개선된 EMI 필터를 설계 제작하여 전자파 노이즈가 내부 또는 외부로 유출.입 되는 것을 방지하고 부하 변동에 따라 특성의 변화가 없는 EMI 필터로 설계 제작하였다.