Design And Iron Loss Calculation Of AC Servo Surface Permanent Magnet Synchronous Motor

The design of permanent magnet synchronous motor is an important device for human life and production to convert electrical energy into mechanical energy.Compared with induction asynchronous motor,it has the advantages of energy saving and simple control strategy.AC servo permanent magnet motor is widely used in various servo positioning systems.Generally speaking,when designing permanent magnet motor with the same power specification,there are many kinds of pole slot matching modes,and different pole slot matching modes have different motor performance.In the design of permanent magnet motor,we need to consider which pole slot match,the motor has better electromagnetic performance.In this paper,the normal winding connection method is used to determine the winding connection mode of 12 slots 4-pole,12 slots 8-pole and 12 slots 10-pole,and the winding coefficient of different pole slot coordination is determined by the unit motor analysis method and slot vector star diagram.A surface mounted AC servo permanent magnet synchronous motor is designed by rmxprt motor circuit calculation software.Compared with the finite element method of permanent magnet motor designed by circuit algorithm,it has higher calculation accuracy.Sine wave permanent magnet and motor should strive to make the air gap magnetic field waveform as sine wave.Taking12 slot 4-pole motor as an example,this paper analyzes the positive air gap magnetic field when the permanent magnet is magnetized in parallel and in radial direction Chord degree.In the servo control system,the motor torque fluctuation is not conducive to the positioning of the motor.The torque fluctuation of the motor is related to the sinusoidal degree of the induced electromotive force,the sinusoidal degree of the stator current and other factors.In this paper,the sinusoidal degree of the induced voltage is discussed by using the finite element method whenthere are three pole slots in 12 slots: 4-pole,8-pole and 10-pole.The torque fluctuation of the motor is calculated by using the finite element method when there are different pole slots.Through the comparative analysis,the pole slot matching mode with the smallest torque fluctuation is determined.Part of the reason of motor torque fluctuation is caused by the cogging torque produced by motor cogging effect.Therefore,it is necessary to reduce the cogging torque in the design of permanent magnet motor.In this paper,the Maxwell stress tensor method is used to analyze the interface stress between rotor and air gap.It is concluded that the cogging torque is caused by the tangential electromagnetic force at the interface.The finite element analysis shows that the slot width and the shape of permanent magnet have influence on the cogging torque.The influence of slot width on the cogging torque is analyzed by using the analytic method and the finite element method.Through the three factors and four levels experiment of constructing permanent magnet,the shape of permanent magnet is optimized and the cogging torque is reduced.The iron loss of permanent magnet motor affects the efficiency of permanent magnet motor.The iron loss is related to the magnetization mode of silicon steel sheet.This paper analyzes the magnetization track of different areas of stator silicon steel sheet by finite element method,and probes into the ways of producing rotating magnetization and irregular rotating magnetization with mosaics measuring device.Combined with the frequency-domain calculation model of alternating magnetization,the iron consumption of electric machine in irregular rotating magnetization is calculated.