Compatibility Investigations of Natural Ester for Capacitor Application

As one of the crucial components in power systems, power capacitors play an important role in energy storage and power quality modification. Currently, most power capacitors are wet-design, with the insulating fluid of mono/dibenzyl toluene (M/DBT). The toxicity and high economic cost of M/DBT makes it of great necessity to explore eco-friendly insulating fluid for capacitor. In this work, to study the feasibility of natural ester (FR3) applied in capacitor, the compatibility of it with the bi-axial oriented polypropylene (BOPP) films were investigated. BOPP films were immersed in M/DBT and FR3 for 168 h and 672 h respectively, and the microstructure and electrical properties of immersed films were examined. The microstructure changes of the impregnation samples showed that few impacts on the microstructure of BOPP films were brought by FR3. Moreover, the insulation properties of BOPP films were enhanced after immersed in FR3. As a result, the good compatibility of BOPP films between FR3 were confirmed, which provided potentials for the application in power capacitors.