• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.149-152
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• 2005

The DC power-bus' resonance is frequently attributed to EMI sources in the PCBs. Subsequently, it will ruin the digital signal integrity within one system or between adjacent systems in the form of conducted or radiated emission. Hence, since it is of importance to examine the PCB's emission, this paper sheds a light on the radiated emission from the power-bus with regards to its resonance modes. A full-wave analysis method is used to calculate the impedance and radiated electric fields and is validated by physics and an EM analysis tool.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.109-113
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• 2001

A high-efficiency electronic ballast for HID lamps is presented. The ballast consists of a PFC and a resonant inverter. To reduce losses of ballast,7C link voltage is determined by taking into account the peak voltage of lamp and a filter-inductor at Bridge diode is employed in order to remove harmonics from PFC. The flux density B$_{m}$ is kept 0.2[T] on all of inductors. A small inductor is connected in series with an electrolytic capacitor of PFC to be operated no high-frequency components. The acoustic resonance is eliminated using the spread spectrum technique. Electronic ballast for 250W metal-halide lamp is implemented and the experimental results show that 97% efficiency, no acoustic resonance and low conducted EMI level.l.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1574_1575
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• 2009

This paper investigates the reduction of RE(Radiated Emission) noise in a high power LED module circuit using PWM(Pulse Width Module) switching controller circuit. Poorly designed LED lighting module can experience the RE and CE(Conducted Emission) noise problem. This paper propose the reduction of noise source and improvement of EMI filter design in a high power LED lighting module. The experimental and simulation results showed that reduce the RE noise level effectively.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.769-773
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• 2004

Conventional SVPWM method has null switching vectors. Null switching vectors cause high common-mode voltage in induction motor drive system. The newly developed common mode voltage reduction PWM technique don't use zero switching state for inverter control. It is realized by changing software without additional hardware. Simulation and experimental results show that proposed method are reduced common mode voltage more than conventional method.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.10
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• pp.530-535
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• 2001

Resonant-type electronic ballast for a metal halide discharge(MHD) lamp is proposed and implemented for 400W MHD lamp. HID lamps have good color rendition, long life and good focusing capability but they have flickers by acoustic resonance when driven at high frequency. A new control method is employed to remove acoustic resonance related instability in HID lamp. By using the amplitude modulation, a spread spectrum effect is employed on the ballast. The control loop of resonant inverter is analyzed and a current is designed. The ballast consists of a power factor controller, an half-bridge resonant inverter, a simple ignitor and an integrator with OP-amps. The experimental results show the good performance as PF 0.93, ballast loss 22W at output 400W and the conducted EMI level is below 60dBuV.

• Journal of electromagnetic engineering and science
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• v.15 no.3
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• pp.129-133
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• 2015

This paper presents the dosimetry of a resonance-based wireless power transfer (RBWPT) system for electric vehicles applications. The compact RBWPT system is designed to transfer power at 150-mm distance. The electric and magnetic fields generated by the RBWPT system and the specific absorption rate in the human body model, which stands around the system, are calculated. These analyses are conducted in two cases: the alignment and the misalignment between the transmitter and the receiver. The matching loops are adjusted to maximize the power transfer efficiency of the RBWPT system for the misalignment condition. When the two cases were compared for the best power transfer efficiency, the specific absorption rates (SAR) in the misalignment case were larger than those in the alignment case. The dosimetric results are discussed in relation to the international safety guidelines.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.124-132
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• 2003

The function and performance test of the developed sub-system should be conducted before integrating into the total system. For the successful achievement of the flight test, the integration tests of sub-systems must be performed to eliminate and prevent abnormal conditions, which may happen due to ground problems, Electro-Magnetic Interference noises, and so on. This paper describes the certification test procedure and results for the roll axis attitude control system of Korea Sounding Rocket-III.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2157-2165
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• 2007

A novel design technology for a high frequency electronic ballast for metal-halide discharge lamps is proposed. A PFC technique is adopted to get unit power factor and output frequency alteration technique is adopted to avoid acoustic resonance. For characteristics evaluation, the designed electronic ballast is presented using normalized parameter. To reduce losses of the ballast. ZVS control technique is adopted and the maximum flux density of magnetic core for inductor should be kept lower. The electronic ballast for 250[W] metal-halide discharge lamp is implemented and 96[%] efficiency and low conducted EMI level are accomplished.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.589-592
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• 2002

The CCM (Continuous Conduction Mode) boost topology is generally used in the PFC (Power Factor Correction) regulator of household air-conditioning systems. There are three kinds of power devices-bridge rectifier diodes, FRDs (Fast Recovery Diodes), and IGBTs (or MOSFETs) - used In a boost PFC regulator. Selecting the appropriate device is very cumbersome work, specially, in the case of FRDs and IGBTs, because there are several considerations as described below: 1) High frequency leakage current regulation (conducted and radiated EMI regulation) 2) Power losses and thermal design 3) Device cost. It should be noted that there are trade-offs between the power loss characteristic of 2) and the other characteristics of 1) and 3). This paper presents a detailed evaluation by using several types of power devices, which can be unintentionally used, to show that optimal selection can be achieved. Based on the given thermal resistances, thermal analysis and design procedures are also described from a practical viewpoint.

• Journal of Power Electronics
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• v.16 no.5
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• pp.1669-1677
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• 2016

A new auxiliary circuit for boost, buck, buck-boost, Cuk, SEPIC, and zeta converters is introduced to provide soft switching for pulse-width modulation converters. In the aforementioned family of DC-DC converters, the main and auxiliary switches turn on under zero current transition (ZCT) and turn off with zero voltage and current transition (ZVZCT). All diodes commutate under soft switching conditions. On the basis of the proposed converter family, the boost topology is analyzed, and its operating modes are presented. The validity of the theoretical analysis is justified by the experimental results of a 100W, 100 kHz prototype. The conducted electromagnetic emissions of the proposed boost converter are measured and found to be lower than those of another ZCT boost converter.