Optimization Design Of Permanent Magnet Synchronous Wind Generator With Inner Magnetic Steel

As the main component of wind power generation equipment,because of its unique structure features,there are many problems in the permanent magnet synchronous generator(PMSG),such as high voltage distortion rate,large cogging torque,large harmonic content,large torque ripple and so on.Especially for the direct drive PMSG,because of the lack of stage gear box,it needs to bear more harmonic,which makes the electric machinery itself need higher quality.Therefore,it is of great significance to study the influence of structural parameters on the electromagnetic performance of PMSG.Meanwhile,according to the requirements of the manufacturer,the optimal design of the 2.935 MW direct-drive PMSG is carried out.Firstly,the mechanical structure and performance characteristics of the existing kinds of permanent magnet synchronous generators were analyzed.And the optimization status of permanent magnet motor was also analyzed and studied,in which the optimization methods including skewed slots,unequal width notches,unequal thickness poles etc were compared and analysed.It is found that the performances of motor,especially for the reduction of its cogging torque,are emphasized in the literature about the optimization status of permanent magnet electric machinery.However,the research about the influence of structural parameters on the direct drive PMSG and its other electromagnetic performance(such as voltage distortion rate,etc)are lacking,which provides a direction for the further optimization design.Next,taking use of the CAD software and the finite element software,the models of the permanent magnet synchronous generator with different structural parameters were established.Through the finite element simulation,it was studied that the changes of structure parameters,which were including the position angle of the rotor ventilation duct,the air gap eccentricity and the pole shift,had what kind of effects on the electromagnetic performance of PMSG,from which the corresponding law of change was obtained.Finally,according to the conclusions,the suitable structure parameters which were used to optimize the design of direct drive PMSM are selected.At the same time,Through the finite element software simulation study,the electromagnetic performance of the motor before and after optimization was compared,from which the optimal design scheme with higher quality was obtained.