Liquid insulation of IGBT modules: Long term chemical compatibility and high voltage endurance testing

To facilitate operation of power electronics for subsea operation at ambient pressure components have to be submerged in a liquid. Equipment and schemes for testing of long term properties have been developed. Several techniques were used to investigate compatibility between a silicone gel and various insulation fluids. Equipment for electric endurance testing of power electronic components at dc stress under controlled temperature and humidity was developed. Performance of high voltage diodes covered with various insulation liquids, coatings and gel covering were studied.