Mathematical model and steady state characteristic analysis of energy storage MMC

Abstract

It is of great significance to calculate the time-domain analytical expressions of capacitor voltage, capacitor current and battery current of energy storage MMC in order to analyse the influencing factors of electrical quantity, equipment selection and parameter optimization. Therefore, the energy storage MMC mathematical model needs to be built. This article first introduces the topologies, control principles, and corresponding working states of the energy storage MMC. Then according to different working conditions, using the switching function or averaged value methods to represent each IGBT in the submodule. According to its topological structure, the differential equations are given, and the time domain mathematical expressions of the energy storage MMC electrical quantities are derived. Finally, comparisons between the theoretical calculation and the simulation results obtained from PSCAD/EMTDC have shown that the proposed mathematical model for energy storage MMC have an acceptable calculation accuracy.