Torque Vibrations on the Mechanism of Wind Turbine Generators Excited by Balanced Network Faults

Wind energy is one of the most popular and economic renewable energy generations. According to the statistics, there is about 3GW wind energy power potentially in Taiwan. If the grid-connected wind turbine generator is subjected to the network faults, the induced electromagnetic torque (E/M torque) leads to torsional torque stresses on turbine mechanism, namely high/low speed shafts and blades. This project employs a single induction machine-infinite system of middle voltage level containing a fixed-speed wind turbine, in order to investigate the wind turbine torque behaviors owing to the most onerous line fault, i.e., three-phase- to-ground fault. From the simulation results, it is found that such a disturbance may pose a major threat on the high speed shaft instead of the low speed shaft or blades.