Fault ride-through control of doubly-fed induction generator based on smart chopper circuit
With the increasing proportion of wind turbines connected to grid,the security and stability problem caused by wind farm separated from power grid are becoming more and more serious.So it is particularly important to im-prove DFIG fault ride through capacity and reduce the occurrence of off-grid events.In view of the problems,existing DFIG fault ride through control schemes are introduces first.Considering that frequently switched of DC chopper circuit is easy to cause voltage waveform distortion and supercapacitor control scheme has high eco-nomic cost,the DFIG fault ride through control scheme based on smart chopper circuit is further proposed.The proposed method is upgraded based on DC chopper circuit.It connects the unloading resistance with the DC bus through DC/DC converter and introduces active power-DC voltage droop control link to adjust the circuit re-sistance power dynamically during fault period.Besides it sets two modes of high and low voltage crossing,which can be started automatically according to grid connected voltage.Finally,the smart chopper circuit con-trol scheme is verified in Matlab/Simulink.The simulation results show that considering the DC bus voltage sup-pression effect,the regulation time for voltage recovery,the distortion degree of rotor current and the economic cost of schemes,fault ride-through control of DFIG based on smart chopper circuit has the most advantages.
doubly-fed induction generatorsupercapacitor energy storagesmart chopper circuitdroop control
万方数据
维普
