Research On Characteristics Of Noise And Vibration For Disc Permanent Magnet Synchronous Motors

Disc Permanent Magnet Synchronous Motor (DPMSM) is a new and special electrical motor. Characteristcs of vibration and noise and pulsating torque are researched in this thesis.Firstly, the analytical calculation method of cogging torque is discussed in this paper. And the calculating software is made by using MATLAB. A 5kW DPMSM can be as a sample machine to verify the validity using this method. And the pulsating torque of a 5kW DPMSM can be measured by using Germany HBM torque and speed measuring system. The problem of misalignment of the rotor and transducer shaft is hardly solved, and the reasonable experiment results are obtained finally. And then many methods reducing cogging torque of PM motors are listed.Secondly, since DPMSM is the structure of axial flux, and because of the different stator structure between common radial flux motors and DPMSM, and it may not be used to calculate the stator natural frequencies (SNF) of DPMSM that some methods and equations are used to calculate radial flux motors. Therefore, the problem of calculating method of SNF for DPMSM is introduced in this paper, and validates this method's feasibility by SNF measurement of a 5kW DPMSM using the noise and vibration measuring equipment produced by Danish B&K. company. And then this method is used in the calculation of noise for DPMSM, and good effect is obtained. Besides, the effect on SNF of DPMSM, when the stator is opening slot, adding winding, and ending cover, is also researched by actual experiments, and some valuable conclusions are realized.Finally, the effect of noise is also discussed on the condition of both generator and controller supply by experiment. It is proved that increasing switching frequency of controller can decrease noise of motors efficiently. And last the problem of frequency spectrum analysis in test is discussed preliminary for a 20kW DPMSM.