• Journal of the Korea Convergence Society
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• 제9권2호
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• pp.1-6
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• 2018

In this study, the investigation results of conducted and radiated emission for DC/DC converter circuit applied in electric vehicles are presented. A frequency spreading circuit was used to improve the EMI characteristics of a power converter designed by using MPQ4433 chip. The frequency spreading circuit using a TLV3201 chip was designed and applied to the power converter. A PCB was fabricated based on the EMI minimization procedures and simulated and measured results were presented for the far-field and near-field conducted and radiated emissions using the fabricated circuit. The measurement were done as CISPR 25 standardized test procedures. It is clearly showed that the EMI characteristics were improved 20% in case frequency spreading was applied. The EMI reduction technique using the frequency spreading proposed in this study was first applied to the design of power converter module for automobile. It is expected that the method presented here can be effectively used for EMI improvement in the future.

• The Transactions of the Korean Institute of Power Electronics
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• 제9권3호
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• pp.260-266
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• 2004

Because the EMI filter is mainly designed by trial and error method, it takes many times to reduce the conducted EMI noise in a power converter. Thus, a newly analytical design procedure is proposed to overcome the problem in this paper. High frequency models of each component are built, md, using the modeling circuits, the filter design is carried out applicable to each mode. Based on the accumulated database for practical components, and the measurement data of EUT with a standard filter, the filler design algorithm is presented. Finally, the validity of the Proposed models and design method is verified through the measurement results.

• Proceedings of the KIPE Conference
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.494-497
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• 2002

Conducted electromagnetic interference (EMI) from switch mode power supplies (SMPS) has become a major problem due to the proliferation of these devices employing dc-dc converters using standard pulse width modulation (PWM). In this paper, we proposed the sigma-delta modulation $({\sum}{\Delta}M)$ as an alternative switching technique to reduce the conducted EMI in SMPS. A comparative investigation on conducted EMI generated by PWM and ${\sum}{\Delta}M$ techniques are experimentally performed on a 300W Boost converter.

• The Transactions of the Korean Institute of Electrical Engineers B
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• 제55권7호
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• pp.374-379
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• 2006

The switch mode power supply is a source of EMI with other equipment as well as with its own proper operation because of rapid changes in voltages and currents within a switching converter. The EMI is transmitted in two forms: radiated and conducted. Conducted noise consists of two categories known as the differential mode and the common mode. Common mode noise current is a major source of EMI in the switch mode Power supply. Recently, a current balancing technique has been studied to reduce the common mode noise. This paper investigates the reduction of common mode noise according to a node expansion of the switch mode power supply which is based on a current balancing technique. In this paper, seven PCB patterns of the forward converter are manufactured and experimented.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1891-1895
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• 2003

Switch-mode power supplies (SMPS) have become a major source of conducted electromagnetic interference (EMI) which is the combination between differential mode (DM) noise and common mode (CM) noise. This paper presents the conducted EMI reduction approach in flyback switched mode power supply by rerouting for circuit balance to reduce common mode noise. And differential mode noise can be reduce by adding $c_x$ capacitor across the input power line, and passive element to the gate drive of switching device MOSFET to slow down the switching times. This combination of our approach is the effective way to reduce the conducted EMI and it is also a cost effective for product design

• Proceedings of the KIPE Conference
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.384-388
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• 2004

High frequency common mode voltage produced by power inverters are a major cause of conducted EMI, creating motor ground currents, bearing currents and other harmful by products. This paper focuses on a new SVPWM method with random PWM injection to reduce conducted EMI noise. A New PWM technique associated with the common mode voltage can be significantly reducing and contributes to mitigate. The common mode voltage to $50\%$ in comparison with that for conventional SVPWM technique. Validation of the theory and reduction methods are then performed experiment ally based on an induction motor drive.

• Journal of the Korea Society for Simulation
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• 제10권4호
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• pp.21-30
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• 2001

In this paper, EMI measurement, the STGU simulation being conducted, filter design, its characteristics, and its implementation to the PCB, and finally test results are discussed. When the low pass filter was implemented within the STGU, the power of EMI decreased more than 20dBm. Finally, when TE and MTIE, two important quality measure in synchronous reference clock, was assessed, ITU-T G813 requirement was satisfied. EMI(Electromagnetic Interface) is a measure of electomagnetic radiation from equipment in the range of 10KHz to 3GHz, and can cause unexpected reactions of electronics/electrical equipment. In this study, for safe and stable communication operation, a STGU (System Timing Generation Unit), which is a 2.5G SDH System and a major EMI source, was employed to simulate electromagnetic interface. Using Open-Site test, the power of fundamental frequency of EMI of interest and its harmonics were measured. Also, a low pass filter at cut-off frequency of 2GHz was specifically designed for this study to minimize the effect of EMI between electronic components.

• 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.

• Journal of Power Electronics
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• 제13권4호
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• pp.619-625
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• 2013

Switched mode power supplies (SMPS) are power electronic circuits extensively used in a wide range of applications. High frequency switching operation of SMPS causes electromagnetic emissions and has the potential to interfere with system operation, which in turn has an impact on system performance. This makes electromagnetic compatibility (EMC) an important concern. In this paper, a new and simple spread spectrum technique is proposed by modulating chaotic pulse position modulation (CPPM) and pulse width modulation (PWM). The resulting CPWM is implemented to reduce the conducted EMI in SMPS. The proposed method is found to be effective in reducing conduction EMI. The effectiveness and simplicity of the proposed method on spreading those dominating frequencies is compared to the EMI mitigation technique using an external chaotic generator. Finally, the levels of conductive EMI with standard PWM, CPWM with an external chaos generator and the proposed method are experimentally verified to comply with the CISPR 22A regulations. The results confirm the effectiveness of the proposed method.

• ETRI Journal
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• 제44권5호
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• pp.759-768
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• 2022

A novel energy harvesting technique that uses conducted electromagnetic interference as an energy source is presented. Conducted EMI generated from fluorescent light using a switched-mode power supply was measured and modeled as an equivalent voltage source. Two types of rectifier circuits-a bridge rectifier and a voltage doubler-were used as the harvesting devices for conducted EMI source. The matching networks were designed based on the equivalent model, and the harvested power was improved. The implemented energy harvester produces a regulated power over 68.9 mW and current over 15.1 mA while a regulated voltage can be selected between 3.3 V and 5 V. The proposed system shows the highest harvesting power indoor environment and can provide enough power for the Internet of Things devices.