Recovery of Photovoltaic Potential-Induced Degradation Utilizing Automatic Indirect Voltage Source

Potential-induced degradation (PID) of photovoltaic (PV) modules is one of the most severe types of degradation in modern modules. PID can affect crystalline silicon PV modules, and while extensive studies have already been conducted in this area, the understanding of how to recover PID is still incomplete, and it remains a significant problem in the PV industry. In this paper, an electronic circuit that can mitigate the impact of PID in PV modules is utilized. This was achieved by inducing the PV string of 1000 V when a threshold current of 100 mA is detected. A microcontroller was used to manage the current sensor data and actuate the whole circuit. The impact of the proposed circuit on PID affected PV modules are (i) improve the electroluminescence regeneration, (ii) increase the output power by up to 30% of newly PID affected modules, and up to 7.8% for old modules, (iii) reduce their temperature, known by hotspots, and (iv) despite the variations in the solar irradiance and temperature, the recovery of the PID can be obtained within 15 days or less

Detecting defects in photovoltaic panels with the help of synchronized thermography

Abstract This paper investigates defects in photovoltaic (PV) panels, more precisely, the location of defects in PV panels. With the help of electrical verification, it is possible to verify the impact of defects on output performances. However, it is not possible to determine the location of defects in order to address the origin of problems, for example, in the manufacturing process of PV panels. In this paper, the focus lies on finding similarities in the location of defect areas in PV panels. Samples were characterized with the help of synchronized thermography and time-resolved thermography in order to obtain infrared (IR) images of PV panels. IR images are helpful to obtain a visual image on the health of PV panels, identify the position of defects, and estimate the influence of defects on the output power. This information can be useful, for example, for improving the fabrication process of PV panels