Analysis Of Electromagnetic And Temperature Field Of PMSM Under Loss Of Excitation Fault

Compared with other traditional non-permanent magnet motors,PMSM has many advantages,such as no excitation device,higher efficiency and higher power factor.These outstanding advantages,the PMSM is widely used in all walks of life and all kinds of work places.However,the permanent magnet of the PMSM is subject to failure.Usually the magnet loss accounts for more than 70% of the magnet loss of the PMSM.Therefore,the analysis of the magnet loss of the PMSM is particularly important.In this thesis,I study a small counter-mounted PMSM and analyze the electromagnetic and temperature changes inside the motor in the event permanent magnet loss from electromagnetic field analysis and temperature field analysis The content of the analysis is as follows:First,Maxwell finite element simulation software is used for the simulation.The finite element electromagnetic simulation model of the motor is established from the parameter data of the PMSM.The finite element analysis method is used to analyze the electromagnetic field of the motor.At the same time,the maximum magnetic induction intensity and the coercive force of the permanent magnet in the motor model are set at the percentage change to simulate the loss of permanent magnet.of the PMSM is established.The electromagnetic output data of the three-phase PMSM in different states of magnet loss is analyzed.Then,based on the electromagnetic data of the motor,a series of rules for varying the electromagnetic output data is obtained,such as air gap magnetic density curve,induced voltage current,copper loss of motor stator winding,iron core loss and slit torque.Provide an important basis for fault diagnosis.Finally,the ohmic loss of the stator coil and the eddy current loss of the stator core under different loads are used as the heat source for the experimental faulty motor.The platform performs a coupling analysis of the two-dimensional distribution of engine temperature.Then,the permanent magnet loss fault model of the motor rotor is simulated and analyzed to obtain the temperature field distribution in different magnet loss fault states.The early warning system of loss of excitation fault is established by extracting the characteristic quantity of air gap flux density and stator temperature.