光伏并网发电系统孤岛检测技术

介绍了孤岛产生原理及其带来的不良影响,分析了传统的无源孤岛检测方法和有源孤岛检测方法,针对已有孤岛检测方法的不足,提出了电压前馈正反馈扰动孤岛检测方法,使公共耦合点电压趋于不稳定,从而通过欠电压/过电压检测判断孤岛的发生.该方法具有无检测盲区,对电能质量影响小,检测速度快等优点.此外,对于多台光伏发电系统并网运行的情况,该方法同样适用.根据IEEE Std.2000-929标准对提出的检测方法进行仿真测试.仿真结果验证了提出的孤岛检测方法的有效性.

Islanding Detection Method for Photovoltaic Grid-Connected Power System

The occurrence cause and negative effects of the islanding are presented in the paper. Traditional passive and active islanding detection methods are discussed. Considering their shortcomings, the voltage feed forward positive feedback disturbance method is proposed to solve the problems. The proposed method leads to the instability of the voltage at the point of common coupling. Therefore, the islanding can be easily detected by using the under-voltage or over-voltage detection. The proposed method is showed to have no non-detection zone (NDZ) and little influence on power quality and fast acting. Besides, it's also effective when multiple photovoltaic grid-connected power systems operate simultaneously. Simulations of the proposed method are carried out according to IEEE Std.2000-929. The simulation results verify its effectiveness.