Investigation of element enrichment in silicone gels used to encapsulate inverter modules for renewable power generation

The focus of this study is to investigate the enrichment of impurities within the silicone gels protecting power electronic modules during application. For this purpose, the power modules of three photovoltaic (PV) string inverters installed at different locations and after an operation time of approximately 8 years were compared with modules tested in a continuous condensation test and the respective reference modules. Impurities found in the silicone gel were correlated to possible sources, such as polymer housing or electronic components.