Feasibility Study on Cancelling the DC Choppers in VSC-HVDCs for Renewable Energy Integration

The VSC-HVDC system for large-scale renewable energy transmission is confronted with the problem of balancing surplus power. The current schemes for configuring AC or DC energy dissipation devices have many problems such as high cost and large land occupation. Therefore, this paper proposes a strategy integrating the distributed energy consumption function (DECF) into the MMC (DECF-MMC), studies its working mechanism, and proposes the AC/DC fault ride through method. The feasibility of the proposed topology and control strategy is verified through electromagnetic transient simulation. The submodule prototypes are developed and experimentally verified. Compared with systems using MMC and DC energy dissipation devices, DECF-MMC achieves AC/DC fault ride-through at a low cost and has economic…