배전계통 연계형 태양광발전 시스템의 계통연계 하이브리드 변압기 적용에 따른 고조파 저감 시뮬레이션 분석

Abstract

As the power trading system diversifies and the amount of power generated by the photovoltaic power generation system increases due to its increased efficiency, the number of photovoltaic power generation system connected to power system is on a rising tendency. The harmonic components, produced in the process of connecting the photovoltaic power generation system to the power system, decrease the power quality of the power system and cause malfunctioning on the measuring devices. In this paper, the reduction of harmonic components are simulated using hybrid transformer instead of grid-connected transformer. The hybrid transformer has zig-zag windings and the voltage phase is shifted about 30 degrees. The hybrid transformer is modeled to have the transformation ratio of 370V / 22,900V. Through the simulation, it can be seen that the harmonic components on the voltage is reduced by min. 2% and the harmonic components on the current is reduced by min. 15%. Therefore, the hybrid transformer can be used in protecting the power system from the harmonic components of the photovoltaic power generation system.