The impact of LVRT characteristic on the stability of Northwest China grid with large scale wind power

The wind power integration in northwest grid will produce great influence on the operation of power grid which is particularly different from conventional power network. The problem of security and stability of the power grid has been prominent, which may intensify with the increase of wind power integration scale and capacity. In this paper, the digital-analog hybrid simulation model of Northwest China grid is built based on the data of summer-peak load in 2015 level year. Based on the model, the security and stability of the northwest power grid is studied by simulating different types of the serious faults on the the wind farm interconnection point and the 750kV transmission lines at the Hexi corridor. Study shows that the different low voltage ride through (LVRT) capability characteristic may cause different impacts on the stability of Northwest China grid with large scale wind power. The voltage index of wind turbines´ LVRT capability and proportion requirements of wind turbines with LVRT capability are put forward to make sure the stability of power system after N-1 faults. Hierarchical control strategy for wind turbine is promoted to prevent system instability after serious faults. It is of great guiding significance on the planning and construction of Northwest China grid, as well as the safety and stability operation of power grid with largescale wind power.