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Analysis of Reduction Effect of Three Harmonic Currents by Zigzag Wiring of Single Phase Transformer

단상 변압기 지그재그 결선에 의한 3고조파 전류 저감 효과 분석

  • Kim, Jong-Gyeum (Dept. of Electrical Engineering, Gangneung-wonju National University) ;
  • Kim, Ji-Myeong (Dept. of Electrical Engineering, Gangneung-wonju National University)
  • Received : 2017.05.09
  • Accepted : 2017.07.19
  • Published : 2017.09.01

Abstract

The three-phase four-wire power distribution system can be used to supply power to single-phase and three-phase loads at the same time. There are linear loads and nonlinear loads as single-phase loads connected to each phase. The nonlinear load generates a harmonic current during the power energy conversion process. In particular, the single-phase nonlinear load has a higher proportion of generation of the third harmonic current than the harmonics of the other orders. In a three-phase four-wire system, the third harmonic current flows through the neutral wire to the power supply side, affecting the power supply side and the line. Furthermore, the magnitude of the current flowing in the neutral line can be higher than the current flowing in the individual phase. If the neutral current is higher than the phase current, the breaker may be blocked. Therefore, it is necessary to reduce the amount of current flowing in the neutral line by harmonics. There is a method of zigzag connecting a single phase transformer by a method of reducing 3 harmonic current. In this study, the method of reducing the magnitude of the three harmonic currents flowing through the zigzag wire by comparing the polarity and the negative polarity characteristics of the single phase transformer was compared through measurement and simulation.

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