In order to reduce per kilowatt hour cost in offshore wind farms and avoid maintenance difficulties caused by accessibility

a fault-tolerant method for wind turbines based on doubly-fed induction generator(DFIG)is put forward. First of all

different hardware reconfiguration schemes are given according to the different locations and characteristics of the open-circuit faults. Then

when single-phase open-circuit fault occurs in machine-side converter

three-phase four-switch inverter modulation signals are optimized and the DC voltage deviation is added at the same time to compensate capacitor voltage fluctuation. Simulation and experimental results show that when single-phase open-circuit fault of DFIG-based wind turbines is occurred

backup-free fault-tolerant operation is realized without redundancy by hardware reconfiguration and software fault tolerance

and the availability ratio of DFIG-based wind turbines is also improved. This work is supported by Shanghai Science and Technology Innovation Action Plan(No. 16DZ1203504).