Research on Thermal Fault Detection and Location of Photovoltaic Connectors Based on Multiple Model Estimator

Offshore photovoltaic (PV) systems encounter challenges due to high humidity and salt spray environments. The PV connectors on the DC input side of inverters are particularly susceptible to increased contact resistance and local overheating caused by environmental corrosion. This paper introduces a novel thermal fault location method utilizing a multiple model estimator (MME). The approach develops a lumped thermal model and an abnormal overheating disturbance model for the PV connectors. By combining a Kalman filter with a probability fusion algorithm, the method effectively detects thermal faults. Simulation and experimental results demonstrate that this approach can accurately locate faults while requiring only a minimal number of thermal sensors, thereby enhancing the reliability of offshore PV systems.