Fault detection for PV systems using Teager-Kaiser energy operator

Owing to economical and environmental concerns, the photovoltaic (PV) technology has been significantly developed over the past few years. To ensure the safe operation of PV systems, it is necessary to develop effective fault detection techniques. Low-fault current of high-impedance, low-mismatch, and low-irradiance faults may lead to they remain undetected, resulting in potential fire hazard and energy loss. The use of blocking diodes and operation of maximum power point tracking algorithm increase the difficulty of PV fault detection. Using the Teager-Kaiser energy operator, a novel index to detect the challenging PV fault conditions without any prior information about the PV array and the training data set is proposed. The proposed index can differentiate the string-to-ground, string-to-string, and open-circuit faults from partial shadings in both grid-connected and islanded modes of operations. Simulation results in MATLAB/Simulink environment validate the performance of the proposed fault detection index.