Interconnection of wind farms with grid using a MTDC network

In the light of the practical project experience, the multi-terminal DC (MTDC) is regarded as one of the preferable solutions to solve the grid interconnection issue of wind generation. This paper mainly focuses on the application of the voltage source converter(VSC) based MTDC technology to integrate large scale wind farms to the electric power grid. A radial MTDC system is explored as the best choice for wind power integration, due to that it can mitigate the fluctuation of the aggregated wind power. Based on the analysis of the VSC model and control, the coordinated control strategy for the proposed MTDC system is designed. The operation performance of a four-terminal MTDC system connecting two DFIG-based wind farms, the local and remote grids is also studied, and the proposed control strategy is adopted to achieve a constant power for long distant transmission to the load center under wind speed variations and faults on DC line.