基于谐波电压与基波频率的被动式孤岛检测方法

Passive Islanding Detection Method Based on Harmonic Voltage and Fundamental Frequency

针对光伏电站独立防孤岛保护装置现有的被动式孤岛检测方法盲区较大,同时频率判据无法区分电网低频与孤岛低频的问题,结合电网实际需求,提出了一种基于并网点谐波电压与基波频率的新型被动式孤岛检测方法.首先,对该方法进行理论分析及防误动措施设计;其次,在孤岛和并网的多种情况下对所述方法进行仿真验证;最后,通过实际发生的孤岛数据验证该方法的有效性.研究表明,该检测方法简单可靠,不仅缩小了检测盲区,而且可区分电网低频和孤岛低频.

The existing passive islanding detection methods of independent anti-islanding protection device in photovoltaic power station have a large non-detection zone,and the frequency criterion is unable to distinguish between the power grid low frequency and the islanding low frequency.This paper proposes a new passive islanding detection method based on the harmonic voltage at point of common coupling(PCC)and the fundamental frequency.Firstly,the method is theoretically analyzed and the anti-misoperation measures are designed.Secondly,the method is simulated and validated under several conditions of islanding and grid-connected modes.Finally,the effectiveness of this method is verified by actual islanding data.The results show that the method is simple and reliable,which can not only narrow the non-detection zone,but also distinguish between the power grid low frequency and the islanding low frequency.