• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2181-2183
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• 1997

In this paper, new photovoltaic system that has 3 step output voltage is proposed. This system use new PWM method named as equivalent area PWM. This method is based on the criterion of the calculation that each area of voltage pulses equals to the integrated value of each time shared division of the reference sinusodial waveform to make a PWM pulse. We applyed this method to 2 step inverter and 3 step inverter and analyzed waveform using FFT.

• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.3
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• pp.184-190
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• 1998

Most buildings and factories are supplied with electric power by three-phase four-wire low voltage electric distribution system. This method pollutes the neutral line and utility sources with harmonic currents. Today, development of power conversion technology and the popularization of computer cause the neutral current to become serious. In this paper, a novel three-phase four-wire active filter is proposed to solve these harmonic problems has two purposes. The first purpose of the proposed active filiter is that the phase current has a sinusoidal waveform shape under the nonlinear load. The second purpose of the proposed active filiter is that the current on the neutral line become zero under the unbalanced power source and under the varring load conditions. The ability of the shunt active filiter has been proved to be excellent through simulations under the varring load conditions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.93-102
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• 1998

This paper describes to control system for AC to DC converter which has been widely used to power source in industrial factory and domestics. In this paper, three-phase PWM AC to DC Boost converter that operates with unity power factor and sinusodial input line currents is presented. The current control of this converter is based on the predicted current control strategy with fixed switching frequency and the line currents track to reference currents within one sampling time interval. By using this control strategy low ripples in the output current and the voltage as well as fast dynamic response are achieved with small dc link capacitance employed.ployed.