Research on Active Decoupling Control of Grid-Connected Inverter Based on HVDC

A new decoupling circuit of flyback inverters is proposed to reduce the second harmonic components of buses and DC side in view of the problems of large number of double harmonic components of power frequency in the grid-connected system of HVDC transmission. Through the control of the switch in the new decoupling control circuit, the capacitor can be effectively discharged sequentially. At the same time, four working stages of decoupled capacitor charging mode and discharge mode are studied based on the control analysis of the topology. Finally, the simulation is completed in Matlab/Simulink and an experimental platform is built in the laboratory. The simulation and experimental results prove the rationality and effectiveness of the decoupling method.