Load Shedding Frequency Modulation Method of D-PMSG Combined with Wind Speed Prediction
The commonly used load reduction and frequency modulation control strategies for directly-driven wind tur-bine with permanent magnet synchronous generator(D-PMSG)lack the consideration of the operation economy and frequency modulation capability of wind turbines,which easily leads to the problems of insufficient frequency modula-tion capability or redundant standby power.So we proposed an optimized load reduction and frequency modulation strat-egy based on variable load reduction rate.Firstly,we divided different wind speed modes,and then established the co-ordinated control scheme of overspeed and variable pitch under different modes.Secondly,considering the two factors of frequency modulation capacity and power generation,the function was designed to obtain the optimal load reduction rate under different working conditions.Since the wind speed fluctuates frequently and the fan control was delayed,we used the wind speed prediction and sliding window method to further adjust the optimal load reduction rate.Finally,we built the system simulation model,and the load shedding rate was dynamically adjusted to participate in the system fre-quency modulation through the improved frequency control.The simulation results show that the proposed control strate-gy can reduce the dynamic deviation of system frequency,prolong the time to reach the lowest value,increase the pow-er generation of the fan and reduce the variation of pitch angle compared with the common strategy under the real-time wind speed and load disturbance.This strategy can meet the demand of frequency modulation,improve the quality of frequency modulation,reduce mechanical wear and increase the economy of fan operation.
directly-driven wind turbine with permanent magnet synchronous generator(D-PMSG)variable load shedding rateoverspeed controlpitch controloptimize load shedding control
万方数据
维普
