Capacitor Voltage Balancing Strategy Based on Zero-Sequence Voltage Injection for Half-Wave Commutated Modular Multilevel Converter

Half-wave commutated modular multilevel converter (HWC-MMC) is suitable for high-voltage large-capacity AC-AC conversion, and an appropriate capacitor voltage balancing strategy is essential. This paper analyzes the condition of capacitor voltage balancing and proposes a capacitor voltage balancing strategy based on optimal zero-sequence voltage injection using the model predictive control. Finally, the simulation is carried out to verify the proposed strategy.