Low Voltage Ride-through and Research on the Control Strategy of Doubly-Fed Wind Power System

Deep Research in the problem of low voltage right through (LVRT) and over-current of rotor after the wind farm’s voltage dropped. Using the protection scheme of the energy dissipation type Crowbar protection circuit on the DC side can consume excess energy of the DC bus and ease the sharp rise of the DC bus voltage, to realize the low voltage ride-through of the wind power generation system. The simulation results show that after the grid voltage dropped, the Crowbar circuit timely cut off can make the rotor current decay rapidly, and ensure the stability of the wind turbine and wind power generation system. And through the theoretical calculation to make sure the range of the optimal resistance of the Crowbar circuit, and then pick out the several average sample value from this range to carry out simulation analysis, which has practical value and guiding significance.