光伏并网发电系统中孤岛效应的研究和应用

Research and application on Islanding effects of Grid-connected Photovoltaic System

光伏并网发电系统除了具有过压、欠压、过频、欠频等常规保护外,还应具有一种特殊的保护功能——孤岛保护。被动孤岛保护相对简单并易于实现,但当PV系统输出功率和负载匹配时,被动式孤岛检测方法失效。因此,本文采用被动式孤岛检测和主动频率偏移(AFD)相结合的孤岛检测方法,实现了孤岛效应的检测和故障保护。

Grid-connected PV systems with over-voltage protection, under-voltage protection, over frequency protection, under frequency protection, general protection, which has a special protective function - islanding protection. Passive islanding protection is relatively simple and easy to implement, but when the PV system output power and the load power are the same, the passive islanding detection method will fail. So this article uses the method with passive adding active frequency drift （AFD） for islanding detection and fault protection.