Optimization Design And Thermal Field Analysis Of Novel High-Speed Amorphous Alloy Permanent Magnet Motor

Permanent magnet synchronous motor(PMSM)has advantages of simple structure,high efficiency and good control characteristics.It is especially suitable for high-speed operation,and is widely used in mechanical processing,flywheel energy storage,high-speed compressor and other fields.Amorphous alloy is a new kind of soft magnetic material with excellent electromagnetic properties.It has the advantages of high permeability,and low loss,especially low loss at high frequency.It is very suitable for high speed and high frequency motors.However,amorphous alloy material is brittle and sensitive to mechanical stress.In this paper,a new-structure amorphous alloy high-speed permanent magnet motor is proposed,which can reduce the impact of permanent magnet rotor on amorphous alloy stator core during assembly.The optimization design,loss calculation and temperature field of the new amorphous alloy high-speed permanent magnet motor are studied.In this thesis,a 4-pole surface-mounted amorphous alloy high-speed permanent magnet synchronous motor(PMSM)with 36 000 r/min and 12 kW is designed by combining combined poles and Halbach arrays.In order to obtain the ideal no-load air-gap flux density waveform,the electromagnetic field of the high-speed permanent magnet motor was calculated by finite element method,and the rotor structure parameters of the PMSM were optimized based on the THD and the fundamental amplitude of air-gap flux density.After optimization by Taguchi method,ideal no-load air gap magnetic density is obtained.The core loss of the optimized amorphous alloy high-speed PMSM is studied thoroughly.A two-dimensional time-stepping finite element model of the stator is established.The waveforms of magnetic density at different positions of iron core varying with time are analyzed under no-load operation,and the distribution of iron loss in different regions of iron core is obtained.A three-dimensional temperature field model of the new-structure amorphous alloy high-speed PMSM is established.The temperature field of the new motor is calculated and analyzed by using the results of three-dimensional electromagnetic field simulation and the loss calculated with improved formula as heat source.The temperature distribution of the permanent magnet corresponding to the amorphous alloy stator structure with different composite materials is given,and the new stator structure of the high-speed motor is optimized.The research results are of great significance to prevent thermal demagnetization of permanent magnets in high-speed permanent magnet motors.