Smart monitoring of potential induced leakage current of photovoltaic under salt mist environment based on passive optical Fabry–Perot interference sensor

Leakage current accelerates the aging of the modules and affects the long-term reliability of photovoltaic (PV) system, which may be exacerbated in salt spray environments. Existing monitoring technologies for leakage current ranging from shunt resistors and hall current sensors offer useful capabilities, but may suffer from limitations in offshore PV applications such as weak anti-electromagnetic interference and unable to passive monitoring. Here, an optical fiber leakage current sensor based on the principle of Fabry-Perot (F‐P) interference is proposed in this article for real-time monitoring of leakage current of PV modules. The sensor exhibits an excellent linearity of 0.994 and a sensitivity of 408.33 pm/kV. The results show that the sensor has the merits of high linearity, passive monitoring, and anti‐electromagnetic interference. Meanwhile, the leakage current behavior of different salt concentrations in high voltage bias experiment was explored by using the sensor. This study represents a preliminary exploration of leakage current monitoring in marine environments, providing basic research data for early monitoring of PV modules degradation and enhanced protection design.