• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.1
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• pp.13-17
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• 2016

EMC (Electro Magnetic Compatibility) of the electrical railway must be ensured for safety of passenger. Maglev trains has not friction between the wheels and the rails because levitation by an permanent magnets, electromagnets and superconducting magnets etc. So, it is advantageous to maintain a high speed without noise and vibrations. In this paper, we investigated that the magnetic field of the before and after installation electromagnetic waves absorber in order to analyze the effects of electromagnetic waves. The theoretical analysis of the electromagnetic wave absorber was simulated using finite element method. The magnetic field properties of electromagnetic waves absorber were measured by EMI (Electro Magnetic Interference) test receiver.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.2
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• pp.30-37
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• 1996

전자기기의 급속한 발전과 사용의 확대로 인해 각종 전자기기간의 전자파 방해현상이 날로 증가되고 있고, 이에 따른 각국의 규제도 한층 강화되어 가고 있는 추세이다. 음성 / 영상수신기 제품에 있어서도 제품의 개발과 방송이 시작된 이래 많은 Noise 방해현상 및 제품내부의 상호간섭에 의한 방해문제로 CISPR, FCC등의 규제를 받아오고 있다. 즉, 오랫동안 적용되어 온 EMI(전자파 방해)외 에도 최근에 와서는 EMS(Immunity; 전자파 내성) 부문이 중요하게 대두되고 있다. 특히, 유럽에 있어서는 CE Mark의 도입으로 전 EU국가가 EMS평가를 강제화하여 규제강도를 강화 하고 있는 등 전세계 대부분의 국가가 규격/시험 항목의 범위를 확대해 가고 있어 이에 대한 대응 이 필수 불가결한 일이라 생각된다. 본 고에서는 EMC 관련 인원들의 이해를 돕고자, 새로이 도입된 국내기준과 기존의 규격인 EN / CISPR을 상호 비교하여 각 규격에 대한 적용범위 및 규격체계에 대해 요약해 보기로 한다.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.793-797
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• 2003

Switching PFC converters are widely used not only to comply the power quality specification but also for maximum efficiency. However switching PFC converters generate serious electromagnetic interference (EMI). In this paper to solve this problem, we applied the APW(Anti Phase Winding) and RPWM(Ran-dom PWM) technique to PFC boost converter and obtained satisfactory results. Simulation and experimental results show the improved harmonic and reduced EMI effect in air-conditioner system.

• Journal of electromagnetic engineering and science
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• v.2 no.2
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• pp.75-80
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• 2002

Signal integrity problems and their possible solutions are addressed in this paper for split power plane of high-speed digital systems. Stitching and decoupling capacitors are proved to be very effective for reducing signal noise, ground bounce as well as electromagnetic radiation from the split power plane. Simulations based on 3D-Finite Difference Time Domain (FDTD) method are utilized for the analysis of practical high frequency multi-layered PC main board.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.390-391
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• 2018

본 논문은 직류단 전원을 공유하는 복수의 인버터로 구성된 시스템에서 EMI 저감을 위한 연동제어 PWM 생성 기법을 제안한다. PWM 제어에 의한 스위칭시 전력단 중성점에서 커먼모드 전압이 생성되고, 기생 캐패시터를 통해 전원라인으로 유입되어 EMI 노이즈가 발생된다. 복수의 인버터 시스템에서도 동일한 현상이 나타나고, 이로인한 불특정한 커먼모드 전류가 발생한다. 본 논문에서는 2개의 인버터를 PWM 시점의 동기제어를 통해 커먼모드 노이즈를 상쇄하고자한다. 제안한 제어 기법을 검증하기 위하여 시뮬레이션으로 분석하며, 간이 실험 통해 검증한다.

• Journal of Advanced Marine Engineering and Technology
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• v.22 no.4
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• pp.538-550
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• 1998

The variable frequency and variable voltage AC source made by a conventional inverter which is composed of power semi-conductors includes much noises in sine wave due to high frequency switching of DC source. In this paper the 3rd low pass LC filter for a variable speed 3 phase induction motor driven by a full bridge inverter is introduced to solve the EMI problem by serious noise current. The utility of a modified 3rd order Butterworth LC filter is confirmed through FFT analysis of sine waves and noiseless ACsource can be obtained by the proposed LC filter. The speed of a 3 phase induction motor driven by a full bridge inverter with a LC filter is satisfactorily controlled by a digital PID controller under the condition of stepwise load and setpoint changes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05a
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• pp.106-108
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• 2002

SMPS는 스위칭을 통해 전력을 변환하므로 높은 dv/dt 및 di/dt 특성을 갖게 된다. 이러한 스위칭특성으로 인해 발생하는 EMI (Electromagnetic Interference) 노이즈는 기기 내부 또는 외부에 간섭을 일으킨다. 미국의 FCC (Federal Communications Commission) 및 유럽 의 CISPR(International Special Committee on Radio Interference) 등의 규정을 만족시키기 위해서 전도성 노이즈에 대한 충분한 이해와 해석이 필요하다. 본 연구는 SMPS에서의 EMI/EMC 대책 구현에 앞서, 전도성노이즈의 기본개념 및 발생/결합 경로를 분석하고 실제로 노이즈를 측정한다. 측정을 위해 Boost 컨버터가 제작/사용된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.11
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• pp.1172-1182
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• 2014

In these days, many kinds of goods are more light and more integrated. As frequency range of mobile applications have increased to improve performance of antenna furthermore, EMI(ElectroMagnetic Interference) problem has frequently caused by disturbance of antenna in device which aggravates other circuit. This paper proposes a technique for the prediction of noise power to the transmission line from antenna located near the line. Although noise power transferred to transmission line is varied by source impedance of antenna and load impedance of transmission line basically, the power magnitude can be presented in a square form of S-parameter between antenna and transmission line due to small variation of transferred power. For this reason, we can use the index expressed the transferred power varied along geometrical shapes of transmission line. As a result, big difference is occurred along location of antenna especially the bended line. And this such experiment is correspond with simulation, these results have meaning physically considering electromagnetic field distribution in near and far field. HFSS of Ansys and CPW with ground is used in this paper.

• Proceedings of the KIEE Conference
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• 2003.07e
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• pp.79-82
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• 2003

The switching-mode power converter has been widely used because of its features of high efficiency and small weight and size. 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. 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. 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.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.1
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• pp.27-33
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• 2016

A pulse-width modulation (PWM) method for common mode noise reduction in a PWM inverter connected to a single-phase grid is proposed in this study. The extensively used conventional switching method may experience common mode voltage problems, which generate current leakage and electromagnetic induction problems. In the proposed switching method, the neutral point of the output voltage is always fixed at both ends of the input voltage to reduce common mode noise. The validity of the proposed method is proven through simulation and experimental results.