Temperature Field Analysis And Optimization Design Of Hybrid Excitation Double-stator Bearingless Switched Reluctance Motor

Bearingless switched reluctance motor(BSRM)has the characteristics of no mechanical wear and high critical speed.BSRMs have broad prospects for development in flywheel energy storage,the shipbuilding industry,high-speed drive industry and other fields.Therefore,the research on BSRMs has become a hot spot in the field of new motor research.Due to the high running speed and complex internal structure of the motor,a large amount of heat will be generated,and the design volume of the motor tends to be miniaturized,which is not conducive to heat dissipation,and the high temperature of the motor will affect the efficiency and service life of the motor.Therefore,the temperature field analysis is particularly important.The topology and operation mechanism,mathematical model,ontology design,electromagnetic characteristic analysis,loss and temperature field analysis and optimization of the hybrid excitation double-stator BSRM are studied in this paper.The main work contents are as follows:Firstly,the torque and suspension force generation mechanism of the motor is analyzed in detail,and the initial design parameters of the motor are determined.A three-dimensional model of the motor is established using finite element software called Ansoft Maxwell to verify the electromagnetic characteristics of the motor.Secondly,the iron loss value of the stator and rotor cores of the motor is calculated by the finite element method.In addition,the copper loss,the mechanical loss and the stray loss of the motor are calculated.Next,based on the basic topology of the motor,a three-dimensional thermal model is established in Ansys Workbench software.The loss is used as a heat source,and set the external environment to natural air-cooling conditions,the heat source is imported into the thermal model in the electromagnetic-thermal unidirectional coupling method for transient thermal analysis.Temperature distribution under natural air-cooling conditions can be observed.Since the motor heats up will also affect the material properties,the electromagnetic-thermal bi-directional coupling method between the electromagnetic field and the temperature field is further studied.Compare the unidirectional coupling result with bi-directional coupling method result and observe the temperature distribution.The results show that the increase in temperature causes the feedback of the material characteristics to change the temperature,and the average temperature of each part of the motor under bi-directional coupling method is higher than that under unidirectional coupling method.Finally,set the average torque,average suspension force and average iron loss as the objective of motor optimization,and use genetic algorithm to solve the optimization of the optimized parameters,and obtain the Pareto optimal solution.A new model of the motor was established according to the optimal solution,and the electromagnetic performance of the new model was compared with the performance before optimization.The result showed that the motor torque and suspension force were higher than before optimization.After temperature field simulation,the temperature ratio of each part of the motor after optimization was lower than before optimization,which verifies the effectiveness of the optimized design.