Investigation of the Potential-Induced Aging Phenomenon of an Insulating Encapsulant for a Photovoltaic Module: From Electrical to Chemical Properties

We analyzed the degradation phenomenon and the mechanism induced by an electrical field of an encapsulant layer for a photovoltaic (PV) module. The discharge number and discharge energy were analyzed by the phase-resolved partial discharge (PRPD) pattern. The changes in functional groups and crystallinity were investigated using infrared spectroscopy, Raman spectroscopy, and differential scanning calorimetry. The PRPD pattern and the calculated discharge energy demonstrated that the overall encapsulant layer had higher partial discharge (PD) resistance. Furthermore, the changes in functional groups and crystallinity reflected the influence of the applied electrical field on the molecular structure. These results could provide valuable information both for the corresponding testing standards for the PV encapsulant material and for designing a novel encapsulant layer with better performance for PV modules in related fields such as solar sail in spacecraft, smart grids, etc.