基于直流漏电流检测的光伏汇流箱系统

摘要

A novel method of detecting the ground leakage current by photovoltaic DC system to explore the positive and negative poles’earth resistance of the photovoltaic circuit and judge the earth fault branch of the photovoltaic circuit is pro⁃posed,which takes C8051F020 as the control center. A novel photovoltaic DC grounding detection system was developed. The current detection function of photovoltaic confluence is used to search which branche in the photovoltaic array has different cur⁃rent value,and find out the earth fault of the photovoltaic array circuit in combination with the detected positive and negative poles’earth resistance of the photovoltaic circuit. It is unnecessary to add any signals to the photovoltaic branches in this meth⁃od. This method has no adverse effect on the photovoltaic system. The detection results are not affected by the distribution capaci⁃tance,and is relatively simple.%以C8051F020型单片机为控制中心，采用一种通过检测光伏直流系统对地漏电流来探测光伏回路正负极接地电阻和判断光伏回路接地故障支路的新方法，研制出新的光伏直流接地探测系统。利用光伏汇流的电流检测功能，寻找出光伏阵列电流数值不同的支路，结合探测光伏回路正负极接地电阻，从而发现光伏阵列回路的对地故障。该方法无须给光伏支路施加任何信号，对光伏系统无任何不良影响，检测结果不受分布电容的影响，检测电路相对简单。