Research on Common-mode Interference Current suppression of active neutral point clamped five-level inverter

Abstract

To solve the problem of common-mode interference current in active neutral point clamped five-level (ANPC-5L) inverter, a common-mode interference current suppression scheme combining four-leg topology and model predictive control (MPC) algorithm is proposed. The common-mode loop model of the transformerless four-leg ANPC-5L inverter is presented firstly. Then the common-mode voltage with different switching states and the effect of factors on the common-mode interference current are analysed. On this basis, this paper adopts feedforward decoupling control algorithm to realize capacitor voltage decoupling control, and reasonably selects the redundant switching state of four-leg ANPC-5L topology by MPC algorithm. The proposed scheme can achieve constant common-mode voltage, so as to effectively suppress the common-mode interference current. The simulation results show that the proposed control methods are effective and feasible.