Eddy Current Loss Analysis And Temperature Field Simulation Of High Speed Permanent Magnet Motor

The high-speed permanent magnet motor has the advantages of high efficiency,high power factor,high reliability and easy maintenance,and the motor is small in size,which reduces the use of motor materials and reduces the cost of the motor.It is used in centrifugal fans,compressors,air pumps and water pumps.Motors have been widely used.In thesis,the electromagnetic field,eddy current field,fluid field and temperature field are comprehensively considered,and the simulation calculation of a high-speed permanent magnet motor for a 70 k W,40000r/min centrifugal fan is carried out.The main research contents are as follows:First of all,according to the design requirements of high-speed permanent magnet motor,the design principle,design characteristics and design process of high-speed permanent magnet motor are analyzed.Through the selection of main parameters of high-speed permanent magnet motor,the structure and size of the stator and rotor core of the motor,the distribution of windings and the windings are designed.The wire diameter of the wire,the matching of the pole and slot,the size of the permanent magnet and the sheath,etc.,will finally determine the complete electromagnetism scheme of the motor.By establishing an electromagnetic model and solving it,the correctness of the motor scheme is checked.Secondly,considering the influence of the high-frequency magnetic field of the high-speed permanent magnet motor on the eddy current loss of the motor,the causes and analytical expressions of the stator core loss are analyzed.The direction of the magnetic field and the alternating magnetic field,the amplitude of the fundamental wave and each harmonic,and the stator iron loss is calculated by comparing the simulation method and the analytical method.The path of rotor eddy current loss under the influence of skin effect is analyzed,and the optimal scheme of eddy current loss is obtained by designing different composite sheaths.Finally,the three-dimensional thermal analysis model of high-speed permanent magnet motor is established.The whole model of the motor is simulated and calculated by ANSYS Fluent simulation software,and the relevant heat dissipation coefficient,thermal conductivity and simulation calculation model of the motor are analyzed.The flow state of fluid in the motor and the temperature change of each part of the motor are simulated.A hybrid cooling model of self fan cooling and water cooling is designed,which improves the heat dissipation path of motor stator and rotor and reduces the temperature rise of motor.The research results show that the electromagnetic scheme of the designed 70 k W,40000r/min high-speed permanent magnet motor meets the requirements;through the calculation of the loss,the designed rotor composite sheath plays a shielding role and reduces the eddy current loss;self-fan cooling,water cooling Compared with the traditional watercooled model,the model has stronger heat dissipation capacity,which is beneficial to reduce the temperature rise of the rotor.