Comparative analysis on critical clearing time of power system connected with large wind farm

The analysis of transient stability of power system connected with large wind farm is an important issue in the planning and operation of wind farm because the reactive power variation and the real power variation of wind farm interconnected with power grid leads to voltage fluctuation and frequency fluctuation of power grid. Impact of large scale wind farm integration on electric power system, effect on electric power system produced by development of wind power in a local grid typically in China has been represented. Based on electromagnetic transient software DIgSILENT/PowerFactory, the interconnected wind farm model and VSC-HVDC model as well as HVAC and HVDC model are set up. Comparative analysis of post-fault transient performance of wind turbines with different type of tie-line has been proposed. As a character of transient stability of power system, critical clearing time of three-phase short-circuit fault is studied in this paper. The digital simulation results show that VSC-HVDC is a better measure to solve the problems of system instability due to large wind farm integration. With VSC-HVDC transmission system, the transient stability of system can be improved better by flexible operation and control. Analysis of this paper should be provided as academic reference for improving design of interconnected wind farm system.