Research On High Voltage Ride Through Of DFIG For Wind Power Generation

With the expanding scale of wind farms and wind power capacity, if theinstalled wind capacity be disconnected from the grid in the case of grid failure,unable to provide frequency and voltage support as conventional energy, it willresult in chain reaction and seriously affect the stability of the grid. Thus, the windpower guidelines will inevitably become increasing high to stabilize the grid.Many studies are about dynamic analysis of DFIG under grid voltage dip andlow voltage ride through strategy, while dynamic analysis of DFIG under gridvoltage swell and corresponding high voltage ride through strategy has not beengiven sufficient attention. This article analyzed high voltage ride through strategy,its main contents are as follows:1）Through rigorous theoretical analysis, derived stator flux and rotor voltageof DFIG under symmetric and asymmetric grid voltage swell, providing atheoretical basis for high voltage ride through protection strategy.2）Detailed analyzed dynamic response of DFIG under grid voltage recovery,derived stator flux and rotor voltage under different grid voltage recovery moment.3）With regard to previous dynamic rotor current, rotor voltage analysis, putforward rotor current and rotor voltage equation of DFIG under symmetrical andunsymmetrical grid voltage swell and verified by MATLAB simulation.4）With regard to High Voltage Ride Through, put forward stator currentfeedback algorithm, conducted its validity through MATLAB simulation andexperiment.