Temperature dependence of self-healing characteristics of metallized polypropylene film

• The temperature dependence of self-healing characteristic is investigated.
• The lifetime of MPPFC under different temperature and voltage is tested.
• Reason of the increase of self-healing area with temperature rise is analyzed.
• Reason of the occurrence of higher catastrophic failure ratio is analyzed.

Thermal aging is one of the main failure mechanisms in metallized polypropylene film capacitors (MPPFCs). Also, catastrophic failure is more likely to happen under elevated working temperature. Elevated temperature will accelerate the aging process of the dielectric, reduce the dielectric strength of polypropylene and influence the self-healing characteristics of metallized polypropylene film (MPPF). In this paper, the lifetime of MPPFCs under different voltage and working temperature is tested, and with a well-designed self-healing experiment bench, self-healing experiment under 20 °C, 40 °C, 60 °C and 85 °C are performed. It is found that the lifetime decreases and catastrophic failure rate increases apparently with the rise of temperature. And the self-healing energy under the same breakdown voltage becomes larger under higher temperature. In this paper, the influence of temperature on self-healing characteristics and capacitor working performance are investigated.