Lifetime Analysis of Metallized Polypropylene Capacitors in Modular Multilevel Converter Based on Finite Element Method

Metallized polypropylene capacitors (MPPCs) are widely used in the modular multilevel converter (MMC) for high-voltage direct-current transmission systems because of their lower power losses and self-healing capability. The performance MPPCs MMC deteriorates with time due to increase equivalent series resistance a decrease capacitance. Therefore, reliability analysis MPPC is critical. This article proposes finite element method (FEM) analyze by considering corrosion failure. First, electric model actual thermal established calculate temperature distribution MPPC. Second, failure analyzed simulated FEM model, lifetime aging film verified traditional floating tests. Finally, voltage each submodule (SM) extracted SM combining model. results show that MMC, SMs arm near dc line or middle part have MPPCs.