A kind of fault handling system and unit structure of doubly-fed wind turbine generator

The invention provides a fault handling system and a unit structure of a doubly-fed wind turbine generator set, wherein the fault handling system of the doubly-fed wind turbine generator set controls three-phase electronic switches K1, K2, K3 and K4 to be sequentially switched on and off according to the situation that the voltage in point of common coupling drops, and selects a mild fault handling controller or a deep fault handling controller to work according to a fault handling logic controller. Adopting the above scheme, by setting hardware circuit and improving software control strategy, the doubly-fed wind turbine can realize voltage drop fault ride-through of different degrees, increase the reactive power generated by the fault handling system of doubly-fed wind turbines and effectively suppress the dynamic overvoltage and overcurrent of the machine-side converter. There is no need to add complex hardware devices, and the control method is simple and convenient for engineering practice. The harmonic pollution on the AC side of the back-to-back PWM converter 102 is reduced, and the DFIG startup and shutdown times of the doubly-fed generator are reduced, which provides a certain technical support for a large number of applications of the doubly-fed wind turbine. 101 106 105 110 111 112 K2 K /PCC T /QF/ K3 - 107 108 104 LCL1 C 103 Fig, 1 Fig, 2