Health indicator construction and health status evaluation for the photovoltaic array based on the current–voltage curve conversion

This paper presents a novel health status evaluation (HSE) method for photovoltaic (PV) arrays based on current–voltage (I–V) curve conversion. The primary objective is to develop a reliable and efficient approach for fault detection and health monitoring of PV systems. First, the proposed method utilizes the I–V conversion method to eliminate the impact of ambient conditions for the measured I–V curves. Then, the health indicator (HI) is calculated by measuring the Euclidean distance (ED) between the normal and faulted I–V curves. Finally, the trapezoidal membership function is used to map HI values to five health grades: healthy, subhealthy, abnormal, poor, and faulted. Detailed explanation of the selection of key HI parameters is provided in experiments, which also demonstrate the rationality and superiority of the trapezoidal membership function. Experimental results showed that the method accurately classifies health grades with an overall accuracy above 99% for both simulation and real-world data. The proposed methods demonstrate high reliability in detecting faults, e.g., partial shading, short-circuit, and degradation. This study provides a robust tool for PV system monitoring and maintenance, offering significant potential for enhancing operational efficiency and reducing maintenance costs in PV plants.