Novle Islanding Detection for PV Generation implemented by d-q Voltage Harmonic Component

Abstract

In this paper, islanding problem of grid-connected PV generation system is discussed. Based on the technology of passive island detection, a novel principle of islanding detection is proposed which is implemented by using the d-q voltage harmonic components. According to the principle that the inverter-side power quality is different from the grid-side power quality at PCC, the characteristic harmonic frequency d-q voltage components of islanding can be extracted by FFT algorithm. Theoretically, the method can eliminate the non-detection zone resulted from the extraction and identification of microscopic variables. Solar grid-connected PV generation model is set up with PSCAD/EMTDC and the proposed islanding detection algorithm is carried out with Matlab. The simulation results show that islanding state can be detected rapidly and effectively. The proposed method has high response speed and no influence on the power quality of the system.