Design And Research Of Semi-direct Drive Permanent Magnet Synchronous Generator With Dual Stator-winding For Wind Turbine

With the rapid development of offshore wind power generation,the large-scale wind turbines have become an inevitable trend,and the demand for fault-tolerant operation functions has also been proposed for wind turbines.Based on this,In this paper,a semi-direct drive dual stator-winding permanent magnet synchronous wind turbine with fault-tolerant operation is designed.When a single winding is damaged or the corresponding transmission line is faulty,it can be isolated,and another complete winding circuit operates normally to achieve fault-tolerant operation of the generator.Therefore,the research on single-winding fault-tolerant operation of semidirect drive dual stator-winding permanent magnet wind turbine has good economic value.The working principle and characteristics of the semi-direct drive dual stator-winding permanent magnet synchronous wind turbine system are introduced,and a 60 kW motor is designed.Combined with the characteristics of low-speed and high-torque of semi-direct drive dual stator-winding permanent magnet motor,the structural characteristics of the rotor of the motor are analyzed.The surface-mounted magnetic pole structure is selected and the basic parameters of the motor are determined.Moreover,the mathematical model of the voltage equation of the motor winding is established,which lays a foundation for the next motor analysis.According to the magnetic pole structure of the motor,the influence of the pole arc eccentricity and the pole arc coefficient on the cogging torque is studied.Through massive calculation,the curve of the cogging torque with the variation of pole arc eccentricity is plotted.It is found that,for a particular motor,the ratio of the cogging torque to the corresponding electromagnetic torque decreases from rapidly to gradually as the pole arc eccentricity increases.The curve of cogging torque with the variation of pole arc coefficient is also drawn.It is found that the ratio of cogging torque to corresponding electromagnetic torque fluctuates continuously with the increase of the pole arc coefficient,which is related to the cogging of the motor.The two-dimensional model and the external circuit model of the generator were established by the finite element simulation software.The no-load analysis,rated load analysis and three-phase short-circuit operation analysis of motor model were implemented.The rationality of the electromagnetic design was verified and the motor power curve was plotted.For the fault-tolerant condition of the dual stator-winding permanent magnet synchronous wind turbine,the influence of the stator winding position distribution on the output power,output voltage and electromagnetic torque of the generator is analyzed.Four different winding schemes of dual stator-winding motor were obtained by different parallel connection of the motor parallel branch windings,and finite element simulation was carried out.Finally,a prototype test platform was built to verify the correctness of theoretical analysis and simulation results.The results show that the dual stator-winding permanent magnet wind turbine can obtain the maximum power output and electromagnetic torque output through the optimal winding combination when the single winding fault occurs and the system is fault-tolerant.