T pattern fuse construction in segment metallized film capacitors based on self-healing characteristics

• A self-healing simulation model is built and its validation is verified.
• Breakdowns in metallized PP film is classified and the differences are described.
• The fuse burn out mechanism is investigated and the burn-out criteria is proposed.
• A simulation model for T pattern segment film is built and is of reference value.

The breakdown happens in metallized polypropylene film (MPPF) capacitor can be classified into two cases: the first one is self-healing, which means that the insulation will recover after the breakdown; the other one is self-healing failure, which means that the capacitor will fail because of short-circuit fault. In this paper, the MPPF capacitor applied in DC filtering which adopt the T pattern segment film technology is investigated. To simulate the two cases mentioned above, a model based on self-healing experiment data is built by Power Systems Computer Aided Design (PSCAD). The current density flowing through the fuse and fuse energy is calculated and analyzed. Meanwhile, the fuse burn-out criteria are investigated according to electrical explosion theory and phase transition energy of segment metallized film fuse. The fuse design methodology of T pattern segment film is presented and a design case is provided.