Research on Active Support Technology for Voltage at PCC of DFIG-based Wind Turbine during LVRT Period

The power grid connected to the wind turbine is often disturbed as the capacity of wind power integration increases. The fault will cause the grid voltage to drop, causing the wind turbines to be taken off the grid over a wide area. This places more stringent requirements on the ability of grid-connected wind turbines to operate in the event of a failure of the grid power supply. For this reason, research into the technology of low-voltage ride-through control systems is becoming more and more important. This paper analyses the operation of a DFIG affected by mains sag. A low-voltage ride-through technology for DFIGs is proposed based on a controlled rheostat. A MATLAB/Simulink environment is used to simulate and verify the method. The results show that the method has a good effect on the improvement of the LVRT capability of the DFIG-based wind turbine.