Reduction Method of Harmonic Current by Distorted Grid Voltage in the Grid-connected Inverter

계통연계형 인버터의 왜곡된 계통전압에 의해 발생하는 전류고조파 저감방법

Phase angle in grid-connected inverter is important information for current control. When different loads are connected to PCC(Point of Common Coupling) of grid, distorted grid voltage is taken place by load utility generating distorted current. Especially, in case the grid voltage is distorted by low order frequency such as $3^{rd}$, $5^{th}$ harmonic, phase angle of PLL output is distorted. This paper analyze problem of current THD(Total Harmonic Distortion) due to distorted phase angle by distorted grid voltage, and propose control method compensating this problem. Also, it‘s validity is verified by simulation and experiment.