Temperature dependence of self-healing characteristics of metallized polypropylene film

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 degrees C, 40 degrees C, 60 degrees C and 85 degrees 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. (C) 2015 Elsevier Ltd. All rights reserved.