• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.245-248
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• 2001

This paper is indicating the problems, which are the conduction loss on the high frequency transformer, the protection of rectification diode as the snubber loss and the stress of switching main devices, as be made high current and high speed in the phase-shift switching full-bridge DC-DC converter is used the power supply’s main circuit of high capacity. To improve those problems, in this paper, it is proposed that is the resonant circuit auxiliary can be reduced conduction losses and stabilized output control. And, it is constructed prototype of the power supply as the result of computer simulations.

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1137-1144
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• 2014

A parallel-feeding AC traction power system increases the power supply capacity and decreases voltage fluctuations, but the circulating power flow caused by the phase difference between the traction substations prevents the system from being widely used. A circuit analysis shows that the circulating power flow increases almost linearly as the phase difference increases, which adds extra load to the system and results in increased power dissipation and load unbalance. In this paper, we suggest a phase shifter for the parallel-feeding AC traction power system. The phase shifter regulates the phase difference and the circulating power flow by injecting quadrature voltage which can be obtained directly from the Scott-connection transformer in the traction substation. A case study involving the phase shifter applied to the traction power system of a Korean high-speed rail system shows that a three-level phase shifter can prevent circulating power flow while the phase difference between substations increases up to 12 degrees, mitigate the load unbalance, and reduce power dissipation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.6
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• pp.85-90
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• 2014

This paper shows a reasonable demand power, that was made by the systematic and statistical way considering actual conditions, such as investigated transformer capacity and peak power for the last 6 years of subway substation customer as to AMR. In this dissertation, it is necessary to analyze the key features and general trend from the investigated data. It made an analysis of the feature parameters, such as average, standard deviation, median, maximum, minimum and thus it was carried by the linear and nonlinear regression analysis. And we studied on the application of a BESS. Analysis showed that the revulsion of capital is about 3 years and 4 months.

• Proceedings of the KIEE Conference
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• summer
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• pp.1316-1318
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• 2004

Tilting train has been developed to increase the operational speed of the trains on conventional lines which have many curves. This train are tilted at curves to compensate for unbalanced carbody centrifugal acceleration to a greater extent than compensation produced by the track cant, so that passengers do not feel centrifugal acceleration and thus trains can run at higher speed at curves. This paper show that results of normal capacity calculations of the electrical equipments such as Main transformer, PWM converter, VVVF inverter, traction motor in TTX(tilting train express) with maximum operation speed 180 km/h

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1078-1080
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• 2003

This paper proposes the boost input type resonant power supply for driving the magnetron device of the high-capacity microwave oven. Circuit topology of the proposed power supply is the boost input type resonant converter which uses the resonance between transformer leakage inductance and resonance capacitance. Proposed power supply obtains high power factor more than 98% through continuous current mode pulse width modulation. To verify the validity of the proposed power supply, operation principle in the steady state is analyzed and experimental results are presented.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.5
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• pp.726-731
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• 2015

An 1 MW PV plant constructed at the Ara campus of Jeju National University in May 2012, which was the biggest roof-top PV plant in Korea and the biggest PV plant in Jeju Island at the time. In this paper the generation characteristics of the plant was analyzed on the basis of the data obtained during 2 years.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.608-611
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• 2001

This paper is indicating the problems, which are the conduction loss on the high frequency transformer, the protection of rectification diode as the snubber loss and the stress of switching main devices, as be made high current and high speed in the phase-shift switching full-bridge DC-DC converter is used the power supply's main circuit of high capacity. In this paper, to improve those problems, it is proposed that is the resonant circuit auxiliary can be reduced conduction losses and stabilized output control. And, it is constructed prototype of the power supply as the result of computer simulations.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.200-201
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• 2007

Tilting train has been developed to increase the operational speed of the trains on conventional lines which have many curves. This train are tilted at curves to compensate for unbalanced carbody centrifugal acceleration to a greater extent than compensation produced by the track cant, so that passengers do not feel centrifugal acceleration and thus trains can run at higher speed at curves. This paper show that results of normal capacity calculations of the electrical equipments such as Main transformer, PWM converter, VVVF inverter, traction motor in TTX(tilting train express) with maximum operation speed 180 km/h.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1604-1606
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• 2005

Tilting train has been developed to increase the operational speed of the trains on conventional lines which have many curves. This train are tilted at curves to compensate for unbalanced carbody centrifugal acceleration to a greater extent than compensation produced by the track cant, so that passengers do not feel centrifugal acceleration and thus trains can run at higher speed at curves. This paper show that results of normal capacity calculations of the electrical equipments such as Main transformer, PWM converter, VVVF inverter, traction motor in TTX(tilting train express) with maximum operation speed 180 km/h

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.115-122
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• 2017

In this paper, we propose a novel power factor compensation system using slidac. The proposed power factor compensation system compensates the power factor by adjusting the output voltage of the slidac. In the conventional power factor compensation system using capacitor bank method, the power factor compensation error occurs depending on the load condition due to the limitation of the compensation capacitor capacity. However, the proposed system can finely change slidac output voltage applied to the capacitor, therefore power factor can be compensated up to 100% without error. We compare the proposed system with the conventional system, and confirm that the proposed system has excellent power factor compensation performance through simulations and experiments. If the proposed power factor compensation system is applied to an industrial field, a power factor compensation performance can be maximized. As a result, it is possible to reduce of electricity prices, reduce of line loss, increase of load capacity, ensure the transmission margin capacity, and reduce the amount of power generation.