Abstract:
Metallized film capacitors often use polypropylene film as the dielectric material. The self-healing properties of the film are the key factors to determine the comprehensive performance of the capacitor. It is urgent to study the structure-activity relationship of the self-healing properties of metallized film. We studied the effects of film structural parameters such as the resistance under multiple physical fields, the thickness of the base film and the structure of the coating on the self-healing characteristics of the metallized film. The self-healing process of the metallized film under actual operating conditions was simulated, and the self-healing morphology of different kinds of metal films after experiments was calculated. Moreover, the self-healing parameters of metallized films with different material properties were summarized and the self-healing mechanism was analyzed. The relationship between the structural parameters of metallized films and their self-healing properties was established. The results show that the influence of metal layer square resistance on the self-healing process is more obvious at high temperatures, and the influence of the lower resistance change at high pressure is very small. With the increase of PP film thickness, the self-healing process of the metal film is aggravated, and the surface of the film is obviously charred when the thickness of the base film is increased to 5.8 μm. The self-healing loss of the metal film with zinc-aluminum alloy as the surface electrode is smaller than that of the pure aluminum metal film, which is conducive to extending the service life of the capacitor. The research in this paper can provide theoretical reference for the design and optimization of domestic metallized membrane structure parameters.