Research On A Novel Design Method Of Series Adjust-speed Permanent Magnet Synchronous Motor

Owing to the advantages of simple structure,high efficiency,high power density and good dynamic performance,the adjust-speed Permanent Magnet Synchronous Motor(PMSM)has been widely used in the fields of industry,commerce,transportation,aviation and so on.It is of great significance to study the design method of adjust-speed PMSM and to develop the efficient,standard and serialized PMSM.At present,the adjust-speed PMSM is mainly designed with reference to the specifications of asynchronous machine.For the machines with same chassis,the punching sheets of stator and rotor would be different due to the difference of the power,the number of poles,the number of slots,etc.,resulting in a wide range of motor punching sheets.In order to shorten the design cycle of the motor,improve the versatility of the motor parts,simplify the process of mass production of the motor,improve the mechanization and automation of production,improve the product quality and reduce the cost,this paper presents a new concept of serialized design for the adjust-speed PMSM,that is,the same number of poles are selected and the same size of the stator and rotor punching sheets are used for the machine with same chassis.For motors with variable speed,the powers with different frequencies would be supplied.Based on this idea,this paper focuses on the design of the adjust-speed PMSM and the main work and achievements are as follows:1)Electromagnetic structure design of the adjust-speed PMSM.In this paper,the basic structure of the adjust-speed PMSM is analyzed,and the V-type structure is selected as the rotor structure of the series motor.The number of poles of the motor is selected.Compared the effects of number of poles on performance and economy,the number of poles of the series motor is determined to be 6 pole.The influence of uneven air gap on the air gap flux,no load potential and cogging torque of the motor is analyzed.A method for calculating the magnetic flux leakage coefficient of interior permanent magnet machine has been put forward.Compared with the result obtained by finite element method,the accuracy of the method is verified.2)Fast and accurate calculation method of cogging torque for interior PMSM and study on method to reduce cogging torque.In view of that the results of the analytical method isn't accurate enough while the calculation period of Finite Element Method(FEM)is long,a fast and accurate calculation method of cogging torque is proposed,which is based on the finite element static field simulation to obtain the air gap magnetic flux density distribution.And the cogging torque is calculated according to the analytical formula.Based on the above research,this paper studies the measures to reduce the cogging torque,mainly analyzes the reasonable selection pole arc coefficient and the method using different combinations of arc coefficient.3)Research on design of series adjust-speed PMSM.The similarity laws for designing the machine with the same power and different speed as well the same speed and different power have been analyzed,which provides the guidance for the derivative design of the series machine.Taking the design of the machine whose stator frame is 160 as an example,the design schemes and results of the electromagnetic calculation of the adjust-speed PMSM with variable speeds is exhibited.The prototype has been manufactured and the FEM simulation and test has been carried out.The test results show that the prototype performances meet the design requirements.