基于高频信号注入法的光伏系统接地故障检测与定位方法  

GROUND FAULT DETECTION AND LOCATION METHOD IN PV SYSTEM BASED ON HIGH FREQUENCY SIGNAL INJECTION

作　　者：孟佳彬 李智华[1] 吴春华[1] 汪飞[1] Meng Jiabin;Li Zhihua;Wu Chunhua;Wang Fei(Shanghai Key Laboratory of Power Station Automation Technology,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学上海市电站自动化技术重点实验室,上海200072

出　　处：《太阳能学报》2020年第12期47-54,共8页Acta Energiae Solaris Sinica

基　　金：国家自然科学基金(51677112)。

摘　　要：为了对光伏系统接地故障进行有效检测及定位,依据光伏组件交流小信号的阻抗特性,提出一种基于高频信号注入的方法。该方法将一定频率范围的高频正弦信号注入到光伏系统与地之间:当接地故障发生时,光伏组件与地形成高频回路,回路阻抗在特定的频率点会发生谐振,导致阻抗幅频特性图出现明显的"凹陷"特征;据此特性可实现接地故障检测,并依据谐振频率处的阻抗幅值变化实现接地故障定位。实验测试结果表明:该方法在不同光照条件、不同接地故障电阻下都能对光伏接地故障进行有效检测和定位。To detect and locate ground fault in PV system,a new method based on high frequency signal injection is proposed according to the AC small signal impedance characteristics of the PV module. High frequency sinusoidal signals in a given frequency range are injected into the PV system and the ground. When a ground fault occurs,PV modules and ground will form a loop for the injected high frequency signals. The impedance characteristics of PV modules will show obvious sag at the resonance frequency,which is quite different from the normal ones. The ground fault in PV series can be detected according to this property,and the location can be calculated based on the amplitude of impedance at resonant frequency. The feasibility and validity of the proposed method under illuminated and dark conditions with different grounding resistances is verified by experiments.

关 键 词：光伏 故障检测 定位 高频注入 接地故障 

分 类 号：TM615[电气工程—电力系统及自动化]