APPLICATION OF CROWBAR PROTECTION ON DFIG-BASED WIND TURBINE CONNECTED TO GRID

To provide voltage stability support in weak transmission networks for the ability of doubly fed induction generators is investigated in this paper. Here we analyzed the response of wind turbines to voltage dips at the point of common coupling and its effects on system stability. In order to support the grid voltage by injecting reactive power during and after grid fault events, we developed a control strategy for the operation of the grid and rotor side converters. To study performance of strategy, it is analyzed for different voltage dips at the point of common coupling of a wind farm and compared with the case when the converters do not provide any voltage support. The Chilean transmission network model is used for the Simulations, because of its radial Configuration it would be a good example of weak power system. In addition to this we are presenting the theoretical analysis of the fault current for the application of crowbar protection. The basic method for the fault current measurement during the unsymmetrical and symmetrical faults in the grid system is discussed. In this paper we presented the analytical model for crowbar protection rather than doing simulation studies in actual.