Multi Point Voltage Control for DFIG wind farms in VSC-MTDC Network

Abstract

Abstract The development of voltage source converter (VSC) based multi-terminal HVDC network (VSC-MTDC) is emerging as the most adaptive approach to managing high penetration of wind energy in long distance.However, MTDC networks depend on highly controllable devices, which may permit not only transporting power, but also assuring secure and stable operation for AC grids. This paper first presents an overview of different control schemes for VSCs in VSC-MTDC network, then proposes a modification scheme of multi-point DC voltage control for wind farms equipped with doubly fed induction generators (DFIG). Finally, the proposed strategy is verified on PSCAD/EMTDC software, and simulation results show that the state of constant power control and constant DC voltage control can be automatically conversed, thus guarantee the stability of DC voltage and the transmission reliability after the power variation in DFIG wind farms and the operation fault at converter stations.