Study of a Modified Flux-Coupling-Type SFCL for Efficient Fault Ride-Through in a PMSG Wind Turbine Under Different Types of Faults

Regarding the permanent-magnet synchronous generator (PMSG)-based wind turbine system, this paper proposes a modified flux-coupling-type superconducting fault current limiter (SFCL) to enhance its fault ride-through (FRT) performance. The modified SFCL's structural principle and theoretical influence on the PMSG ride through capability are conducted, and a comparison of the SFCL and a dynamic braking chopper (BC) is performed. Using MATLAB, a detailed model of a 1.5-MW PMSG-based wind turbine integrated with the SFCL/BC is built, and the simulations of symmetrical and asymmetrical faults are done. From the results, introducing the modified SFCL can limit the fault currents in the generator and grid sides. In addition, using the modified SFCL, we are able to compensate the generator voltage and alleviate the dc-link overvoltage. Thus, the wind turbine system's power balance is improved, and also the fault recovery process can be accelerated. On the whole, the modified SFCL is better than the BC for assisting the FRT operation of the PMSG.