• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.3
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• pp.44-49
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• 2007

This paper proposes converter that new soft switching active snubber circuit is added, the resonance energy return to life rate doing maximum whole efficiency increase. Proposed converter adds auxiliary switch and resonance inductor, resonance capacitor, two diodes to existing converter, all switch elements play turn-on/turn-off under soft switching condition and minimized switching losses. Conduction loss department is that watch layer bringing back to life resonance energy by input perfectly. These result proved through simulation and an experiment.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.1
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• pp.98-106
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• 2007

This paper represent improved on-line turn off angle control schemes for switched reluctance motors based on current control. For the purpose of finding the optimal commutation switching angle point with improved controller, it is utilized turn on and turn off position calculation with inductance vs. current vs. not linkage analysis method. The goal of proposed paper is the maximization of the energy conversion per stroke and torque ripple reduction and obtaining approximately flat-topped current waveform. The proposed control scheme is demonstrated simulation and on a prototype experimental system.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.34-36
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• 2007

A new soft switching boost converter is proposed in this paper. The conventional boost converter generates switching losses at turn on and off. Because of that, the whole system efficiency is reduced. The proposed converter utilizes soft switching method using an auxiliary switch and resonant circuit. Thus, the converter reduces switching losses lower than ones of hard switching method. The proposed soft switching boost converter can be applied to photovoltaic system, power factor correction circuit and so on.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.358-360
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• 1999

This paper presents a new soft-switching partial series resonant DC/DC converter (PSRC) with zero-voltage on/off simultaneously, suitable for application in the high power and high frequency switching. The proposed converter has not only advantages of the conventional PSRC but also zero-voltage turn-on and turn-off of the main switches for the entire load ranges by adding the auxiliary circuit, and zero-voltage-switching (ZVS) turn-on of the auxiliary switches. The operation principles of the new converter are explained in detail and the several interesting simulation and experimental results verify the validity of the proposed circuit.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.6
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• pp.510-516
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• 2017

This paper proposes a single-stage interleaved totem-pole on-board battery charger with a simple structure and a reduced component count. Apart from achieving ZVS turn-on of all switches and ZCS turn-off of all diodes, this charger does not require an input filter due to its CCM operation and bulky electrolytic capacitors, which in turn result in a high power density. A single-stage power conversion technique is applied to the interleaved structure in order to achieve a high power density and high efficiency. A 2.5 kW prototype of the proposed charger is also built and tested to validate the proposed operation.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.1045-1048
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• 1999

In this paper, we report on a set of new algorithms to realize a nonlinear compressed-domain video/audio editor that overcomes various realization problems. For efficiency, the underlying algorithm, which uses a central data structure in the form of doubled linked lists, performs soft edits of cut and paste (which, in turn, involves soft implementations of frame type conversion) and addresses problems relating to video/audio synchronization and random access, and decoder buffer control.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.643-644
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• 2006

The purpose of this study is to experimentally analyze swing motion with soft golf clubs and compare with that with normal golf clubs. Soft golf is newly devised recreational sport based on golf but focus on the playability for the elderly. The subject fur the experiment performed swing motion using a normal golf club and a soft golf club in turn. The swing motion of the subjects was tracked using an opto-electric three-dimensional motion analysis system. The results were compared against those obtained with a normal golf club. The range of motion was analyzed along with top head speed for two cases. It was found that higher club head speed could be achieved with reduced range of motion at lumbar joint using soft golf club when compared against the swing using regular club. The lower range of motion fur lumbar bending means reduced risk of injury at the joint. So, it is projected that we can reduce the risk of injury with soft golf while maintaining the club head speed.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.423-428
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• 2005

If the load of constructing vehicles during the construction work acts on the road or the ground surface on the soft ground, due to the excess stresses in soils the trafficability of the vehicles influences the constructing efficiency, constructing period and so on. Stress distribution in soils is the very important element to design and to solve the problems of settlement, safety of foundations and trafficability of constructing vehicle in civil engineering. This research represents the comparative estimation of the actual and theoretical measurement on the underground stress of outer layer for each soil after the observation of each top soil layer for its vertical and horizontal stress in (1)homogeneous sand ground (2) weak stratum with the sand soil (3) weak stratum with gravel of the soil model, and it also investigates the effect of subsidence of ground by the repeated load. The underground stress turn out to be different in the value of theoretical and actual measurement after the trial examination of model.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.189-191
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• 2018

This paper introduces a novel ZVS interleaved totem-pole PFC with the reduced circulating current and the reverse recovery current of the diodes. With the help of a simple auxiliary inductor, both ZVS turn-on of the main switches and soft turn-off of the body diodes can be achieved. In the proposed totem-pole PFC topology since the switching losses and the reverse recovery losses can be significantly reduced, the typical Si MOSFETs can be employed. In addition the circulating current is reduced by adjusting the switching frequency. The proposed PFC topology can be a low cost solution to achieve high efficiency in high power PFC applications. The validity and the feasibility of the proposed topology is verified by the experimental results with a 3.3kW interleaved totem-pole PFC converter.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.121-123
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• 2008

A high efficiency soft switching boost converter is proposed in this paper. The conventional boost converter generates switching losses at turn on and off. Because of those, the whole system efficiency is reduced. The proposed converter utilizes soft switching method using resonant circuit with an auxiliary switch. Therefore, the proposed converter reduces switching losses lower than the hard switching. The proposed soft switching boost converter can be applied to photovoltaic system, power factor correction circuit and etc.