Temperature Influence on Self-Healing Characteristics of Metallized Film Capacitors

The main self-healing characteristics of commercial PET and PP capacitors were investigated over a wide temperature range from −40 to +100 Celsius degrees. It was found that the electrical strength is inversely proportional to temperature for both types of capacitors. The average self-healing energy ranges from 50 mJ (100 °C) to 100 mJ (−40 °C) for PET capacitors and from 100 mJ (100 °C) to 500 mJ (−40 °C) for PP capacitors. It was found that the cumulative failure energy values for PET capacitors exceed those for PP capacitors up to 100 °C. Dependencies of relative capacitance $\left(C/C_{0}\right)$ and relative dielectric losses $\left(\tan \delta / \tan \delta_{0}\right)$ at a frequency of 1 kHz were also obtained over a wide temperature range.