基于功率扰动单相光伏并网系统的孤岛检测方法

由于光伏发电系统是通过逆变器作为桥梁与电力系统实现并网,为了保障电网安全稳定,抗孤岛检测成为光伏并网的关键技术之一。在研究现有传统被动式和主动式孤岛检测方法的基础上,根据电网稳定电压边界条件,通过设定阈值提出了基于光伏逆变输出功率扰动的复合式孤岛检测方法。结合IEEE.Std.2000-929和UL1741技术规范,阐述了该方法的工作机理、阈值整定与实现过程。仿真分析表明,该方法在逆变器输出功率与负载消耗功率匹配度较高时,能够实现快速的孤岛检测,无检测盲区和谐波污染,验证了理论方法的正确性,实现了光伏系统友好型并网。

Method of Single Phase Photovoltaic Grid-connected System Islanding Detection Based on Power Disturbance

Photovoltaic power generation systems usually apply inverters as the bridge to realize grid connection with power system, and in order to ensure the safety and stability of the power network, anti-islanding detection has become one of the most important techniques for photovoltaic grid-connection. Based on analyzing traditional passive and active islanding detection methods, a new method of compound islanding detection based on the photovoltaic inverter output disturbance is proposed to overcome the frequently disturbed shortcomings in traditional methods. With technical specifications of IEEE Std. 2000-929 and UL1741, the working mechanism, threshold setting and realization were described. Simulation analysis proves that the method can achieve rapid island detection when the matching degree of the output power of the inverter with the load consumed power is high, without non-detection zone and harmonic pollution.