A New MMC-LCC DC Converter Topology with No Reactive Power Consumption

This paper presents a new MMC-LCC DC converter, including the topology structure, operating principle, basic control strategy and economic analysis. This new converter adopts multiple modular capacitors between the converter transformer and valves of the conventional LCC topology. The capacitors are switched on to provide auxiliary commutation voltage to help commutate before the natural commutation point in rectifier or after the commutation ending point in inverter, and switched off after the commutation procedure, achieving no reactive power consumption even reactive power generation. The comparison to other topologies is conducted and control strategy is designed to not increase the insultation requirement. The basic main circuit equation is deduced and real project parameters are evaluated for economic analysis. The performance of the converter is validated by EMTDC simulation and the result shows that the project benefit will be significant compared to LCC.