Geometric optimization of self-healing power capacitor with consideration of multiple factors

To decrease temperature rise in self-healing power capacitor and lay foundation for improvement of applied voltage and lifetime, the influence of elements orientation on the temperature distribution of self-healing capacitor is investigated using Fluent15.0 and validated by thermal stability test. Based on the above investigations, the influences of parameters of film, electrode and element on power loss and temperature rise of capacitor are systematically investigated. The results reveal that if geometry and volume of capacitor remain constant, orientation of spray coating has little influence on temperature rise. In view of manufacturing processes, the mode of spray coating close to the large surface should be selected. The power loss will decrease with increasing/decreasing in film thickness/width. Therefore, thicker film should be selected and its width should be less than 75 mm. Temperature rise decreases slowly with element diameter. However, the element diameter should be a moderate value because of the influence of it on the number of self-healing point. A capacitor group with rated voltage of 11/ 3 kV and capacity of 334 kvar is designed and the scheme with the lowest temperature rise is selected. This study provides a reference to self-healing capacitor geometric optimization and lifetime improvement. •Thermal field model of self-healing capacitor is formulated and validated by test.•Influence of element arrangement, diameter on temperature rise is studied.•Influence of film, electrode parameters on power loss is theoretically analyzed.•Suggestions for capacitor, element, film, electrode parameters selection are given.•Self-healing capacitor group is designed and optimized to reduce temperature rise.