Integrated Design Of Permanent Magnet Synchronous Motor Servo System For Variable Pitch

With the increasing of energy consumption and the increasingly serious environmental pollution,wind power has become a new development direction of the world energy industry,and its power generation technology is developing rapidly.The electric pitch control system,as an important executing mechanism of power control and safe and stable operation in wind power generation system,plays an important role in the whole generation system.Because of the complexity,nonlinearity and time variability of wind power system,it is required that the pitch control system has the characteristics of good dynamic response performance,high steady-state precision and strong adaptability.According to the key research and development project of Hunan province(2015GK2004),the integrated design of permanent magnet synchronous motor servo system for wind turbine pitch is studied in this paper,the main contents are as follows:In this study,starting from the variable pitch permanent magnet servo motor,the demand analysis is carried out according to the load demand of the wind turbine blades.The operating characteristics of permanent magnet servo motor under the condition of rotor flux field oriented control are analyzed,and the constraint conditions between the stator voltage of the motor and the DC bus voltage of the converter are obtained.Through the calculation of magnetic circuit and electromagnetic analysis,the main body design and finite element analysis of the variable pitch permanent magnet servo motor are carried out to ensure that the designed motor satisfies the requirements of the operating characteristics of the wind turbine pitch control system.Then the pole arc coefficients of the variable pitch permanent magnet servo motor are optimized and the cogging torque of the motor is reduced due to the performance requirements of the pitch control system and the operating characteristics of the permanent magnet servo motor.In order to fully play the motor performance,further reduce the torque ripple and improve control accuracy.In this paper,a kind of magnetic pole eccentric structure is used,which has little influence on the parameter optimization of pole arc coefficient and is simple and efficient.The finite element simulation shows that it can greatly weaken the motor cogging torque,and to a certain extent,the motor back EMF waveform is improved.Finally,in order to verify the rationality of the optimal designed variable pitch permanent magnet servo motor and the converter control strategy.Based on the Simplorer software and the finite element simulation model of the motor maxwell2 d,a combined simulation model of the field-circuit coupling of the PMSM control system is established under the condition of rotor flux field orientation control,and the operating principle of each module in the model is explained and analyzed in detail.Under different operating conditions,the performance of variable pitch permanent magnet servo motor is simulated and the integrated simulation model is obtained to meet the control accuracy and dynamic response performance requirements of the wind turbine pitch control system.