Requirement for LVRT Capability of Wind Turbine Generator in Power System

The authors present the low voltage ride-though (LVRT) characteristic and the control strategy of wind turbine with LVRT in detail. The model and the control strategy of doubly-fed induction generator (DFIG) with LVRT are implemented in power system simulation tool DIgSILENT/ PowerFactory. The simulation of a certain domestic 220kV power grid is implemented and a method to decide the LVRT parameters of wind turbine generator and requirement is proposed. By means of calculating the terminal voltages of wind turbine generators at the short circuit moment while short circuit takes place in all buses in the power grid one after another, the impact extents of short circuits occurred in different buses of the grid to terminal voltages of wind turbine generators are marked up in geographical wiring diagram, then on this basis the voltage limit of LVRT of wind farm is given. Analysis results show that it may be somewhat unrealistic that under certain conditions to make a claim to wind turbines with very trenchant LVRT ability; and yet under other conditions it is required that the wind turbines possess more strict LVRT ability, otherwise the stable operation of power grid may be endangered. Thus, the voltage limit of LVRT of wind farm should be calculated according to actual wiring scheme.