Research On The Motor Loss And Temperature Rise Of Switched Reluctance Motor

Switched reluctance motor(SRM) has special construction. Only the stator is provided withconcentrated windings, and its working mechanism is different from traditional AC motor. However,the analysis for magnetic field of SRM is very complicated since the flux waveforms in different partsof the motor vary with motor phase,stator pole and rotor number, also with the winding connections,working state,etc.It makes the calculation of losses, especially iron loss,difficult. Loss of energy willeventually be converted into heat, bring about the temperature rise of the motor iron core and thewinding, and cut down the service life of the motor. Thus, the temperature rise analysis is the key toimprove the performance of SRM. At present, the research about heat or iron loss is still not enough.In most cases, we calculate or estimate the rion loss and temperature rise according to the empiricalformula, but analysis of temperature rise especially transient heat still needs deep research. Therefore,this paper will give a series of research on losses and temperature rise of SRM.A brief introduction about the situation about loss analysis and temperature rise is given.Then,the simulation model of12/8dual-channel SRM which works on the power state is built byJMAG-Stduio finite element analysis software. Then, analyze the distribution of magnetic field, andget the regularity of the magnetic flux density at each point of the core. Based on the magnetic fielddata, the double-frequency method is used to separate iron loss into eddy current loss and magnetichysteresis loss. Eddy current loss is computed by frequency analysis method, but the hysteresis loss iscalculated by frequency decomposition method and the maximum magnetic flux density method. Onbasis of the result of iron loss and copper loss, the analysis of temperature rise is done. Transientthermal analysis of SRM lays the foundation for the optimization design of the motor. Those results ofdifferent kinds of connection way of the winding are compared, too.A test platform whose key controller is dsPIC33F and CPLD, with rated voltage of270V, ratedpower of7.5kW, is built. Design the hardware and software module to realize the generation of power.According the test result of voltage, current, torque, power, the calculation of iron loss is finishedindirectly. Those results verify that the selected iron loss calculation method is reasonable.