Research On Electromagnetic Heat Multi-physical Field Analysis Method Of Switched Reluctance Motor

The magnetic density analysis and iron loss calculation of switched reluctance motor have always been difficult tasks in the research.In this paper,a 2D finite element analysis model of SRM was constructed in Flux software based on basic structural parameters of an actual four-phase 8/6 switched reluctance motor.Firstly,a simulation model of the four-phase 8/6 switched reluctance motor was built in the static field,and the magnetic density distribution of the motor in one cycle was obtained.The torque variation with motor rotor position and current was analysed.A four-phase 8/6 switched reluctance motor simulation model was then built in the transient field,where the magnetic density characteristics of the motor at different characteristic points and different paths were investigated and analysed to obtain the variation of the magnetic density of each part of the motor core in one cycle.The magnetic density distribution of the switched reluctance motor was significantly different due to the huge change of the inductive mutual inductance and the magnetic chain of the motor under different pole distribution methods,so that the similarities and differences in the magnetic density distribution of switched reluctance motors were analysed for two typical pole distributions(NNNN-SSSS and NNSN-SSNS).Secondly,the corresponding calculation methods were proposed for the various losses during the operation.The coefficients of the Bertotti formula were obtained by fitting the multi-frequency B-P curve of the iron consumption of a 50DW-470 silicon steel sheet according to the Steinmetz formula and the Bertotti formula for iron consumption.a model for calculating the iron consumption of switched reluctance motors was built with the magnetic density,hysteresis loss coefficient and eddy current loss coefficient of the motor imported into the finite element software and the iron consumption of each part under different operating conditions was calculated.Finally,a thermal analysis simulation model of the switched reluctance motor was constructed in the software which analysed the temperature rise of the winding side of the motor at different speeds and load torques.A switched reluctance motor temperature rise experimental platform based on the structure of four-phase 8/6 was built to measure the temperature rise at the winding side of the motor under different operating conditions,and the results were compared with the finite element simulation results of the motor thermal analysis to verify the accuracy of the analysis simulation.At last,a summary of the work of the full paper was presented and further ideas were proposed.