| The dissertation focuses on the torque analysis on transmission system and control optimization to reduce torque shock,and improve the utilization of the wind power,when apply the squirrel cage asynchronous motor(SCAM) in wind power generation system.The SCAM wind power generation system conclude two kinds of scheme:stall regulated wind power system which run at fixed speed,and variable speed constant frequency wind power system(VSCF),which combined with SCIM and back to back 4 quadrant converter.The two kinds of system both include the gear box and transmission shafts,which is a weak point,and easy to be damaged.Combine with the work of the optimization control of the 750kW wind turbine, the flexible shaft model of the 750kW stall regulated wind power system is set up. Using this model,procedure of cut-in and cut-off are simulated.With the experimental data in wind farm,the causes of the electrical and mechanical shock while cut-in are analyzed.Also the solutions to reduce the shock are given out.Speed gradient and sectional control methods are put forward to optimize the cut-in procedure.Torque oscillation while cut-off is analyzed,and procedure of cut-off is optimized to reduce the oscillation.Through these measures,the operation reliability of s48/750kW wind turbine is improved greatly.The wind power absorption model of VSCF system is built up.Procedure of cut-in and cut-off for VSCF system and torque on transmission system are simulated. The speed control mode and torque control mode are given out in operation procedure. The two modes are compared in detail.The method to reduce the torque shock while change of the wind speed is researched.Maximum power point tracking(MPPT) Control algorithm based on expert system is proposed for speed control mode.Swiftness,stability,and efficiency of this method are tested by simulation and experiment.Using mixed sensitivity function,a speed regulator is designed for the MPPT block.Torque shock brought by speed measure error and MPPT disturbers brought by speed fluctuate are reduced greatly.The space model of 4-quadrant converter(4QC) is used to analyze the current PWM method of supply side converter.The stability of this method is proved.Using self-optimized method,the control parameters are determined. An indirect vector-control system of SCIG is presented in this dissertation according to feature of wind power system.Current PWM control method is applied in the control of the machine.The FIR is used in the system to obtain the reliability and stability.An experiment system was built up in the lab,which can simulate the wind power generation conveniently.The experiment result and simulation result are give out.
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