Thermal Modelling And Sensitivity Analysis For Switched Reluctance Motor

Switched reluctance motor(SRM)possesses a unique geometric structure.There are concentrated windings only on its stator poles.Compared with the conventional induction motor,the working principle of SRM is greatly different.The electromagnetic flux density of SRM is restrained by various factors,such as the motor phase number,the number of stator teeth poles and rotor teeth poles,the winding connection mode and the operating conditions of the motor.Due to the non-linearity of electromagnetic flux density,it is more difficult to calculate the motor losses,especially the iron losses,which makes it difficult to obtain the temperature of the SRM.As is commonly known,the losses of the motor energy are eventually transformed into heat energy,which will increase the temperatures of the stator,rotor and winding,thus,affecting the operational life span of the motor.Therefore,the thermal analysis of the motor is the key to improve the performance of the SRM.In this paper,the research on the thermal modelling and thermal sensitivity analysis are carried out.Firstly,the research situation of thermal analysis for SRM at home and abroad is introduced.The calculation methods of thermal parameters of the SRM are respectively discussed and analyzed.The related thermal parameters mainly include the heat source of the SRM,the equivalent thermal conductivity coefficient of the SRM windings and the heat exchange coefficient of the motor.On this basis,the equivalent thermal network model and two-dimensional finite element thermal model of a switched reluctance motor with 8/6 structure are established based on the thermal analysis theory and method.In order to validate the thermal simulation model,a temperature test platform for the SRM is built on the experimental platform of the prototype,and the SRM is experimentally studied.Based on the thermal simulation model of the SRM,the effects of different winding connection modes and different rotational speeds on the temperature of the motor are studied respectively.The simulation results of the thermal models and the experimental results of prototype are compared and analyzed,through which the validity and correctness of the equivalent thermal circuit model and the finite element thermal model of motor are well verified.For further thermal analysis on the SRM,from the point of view of motor body design,the influence of motor geometric structure sizes on the motor temperature is discussed and analyzed.Finally,the work of this paper is summarized and some ideas for further work are given.