Research on Anti-Islanding Technology for Photovoltaic Grid-Connected Based on the Positive Power Feedback

Abstract

The standards of grid-connected photovoltaic (PV) system and the cause of islanding in formation are introduced at first, and then common passive and active detecting islanding methods are discussed in this paper. Considering the shortcomings of traditional methods, such as failing to detect islanding, larger non-detection zone and poor quality of output power of the inverter, etc., a novel detecting method which is called as positive power feedback disturbance is proposed, so as to overcome these problems. The proposed method has the characteristics of no non-detection zone, little influence on power quality and rapid respond. Finally, according to professional standards of IEEE Std. 2000-929 and UL1471, the simulation as well as the experiment of the proposed method was carried out. The results of simulation and experiment showed the good expressions from the novel method.