Fast Calculation Method for Electrical Quantities of Power Grid including Wind Turbine Generators

Most wind turbine generators (WTG) are operated under grid-following control and can quickly response during grid faults according to pre-designed fault ride-through (FRT) strategies, so their external characteristics during grid faults are quite different from those of synchronous machines, which makes it more difficult to analyze and calculate electrical quantities after grid faults. To solve this problem, this paper first establishes an equivalent controlled voltage source model for permanent magnet synchronous generator (PMSG) according to the typical FRT strategy. Based on this model, the nonlinearity in the fault calculation introduced by WTG integration is simplified to linear equations through reasonable approximation and correction, and the fast calculation of node voltages and branch circuit currents after grid fault is realized. The accuracy of the proposed fast calculation method is verified by simulation in DlgSILENT Powerfactory.