Inter-arm Voltage Balance Control of a Modular Multilevel Matrix Converter with Injecting Dual Frequency Circulating Current

This paper presents an inter-arm capacitor voltage balance control strategy for a modular multilevel matrix converter (M3C) with injecting dual frequency circulating currents (DFCC). The proposed method enforces that the injected input-frequency circulating currents and the output-frequency circulating currents only flow within the nine arms of M3C under arbitrary unbalanced power transmission conditions. The strategy aims to balance the energy across the nine arms to provide superior harmonic performance in both input and output grid sides even during transient processes when compared to the existing single frequency injection method. Comparative simulation results obtained using Matlab/Simulink demonstrate the performance and effectiveness of the proposed control strategy.