Study on the Correlation Among Self-Healing Parameters in Metallized Films

Metallized polypropylene film capacitors (MPPFCs) are an important structure in superconducting magnetic energy storage (SMES) systems. This article systematically investigates the correlation mechanisms between self-healing parameters in metallized polypropylene films (MPPFs) under different environmental conditions. Results show that elevated temperature at$65~^{\circ }$C enhances plasma activity, increasing self-healing energy to 6.5 mJ, three times higher than$25~^{\circ }$C, while thermal expansion mismatch between metallized layer and polypropylene layer at$85~^{\circ }$C induces activity in self-healing process. Pressure, however, reduces the self-healing energy from 0.2 to 10 MPa and changes the situation of the polypropylene layer’s surface, causing damage to the hydrophobic property in the polypropylene layer. The data of arc initiation time and arc extinction time in the self-healing waveform exhibit a two-stage development, representing two stages of the self-healing process under different conditions. Finally, a self-healing simulation model was developed and validated against experimental data, successfully replicating the non monotonic trend in the self-healing area, which is an initial increase followed by a reduction with rising temperature.