Thermal Analysis of Switched Reluctance Machine under Steady State and Transient Conditions

To improve the performance and the life time of the Switched Reluctance Machine (SRM), a two dimensional (2-D) steady state and transient thermal analysis is carried out to observe actual heat distribution in the parts of the machine using finite element method. Electromagnetic losses which form the heat source are calculated taking into consideration both skin effect and proximity effect. A 2-D steady state analysis is done to observe the temperature distribution and maximum temperature for wide range of speed and load conditions. From the analysis it is found that the maximum temperature is reached in the speed range of 1500 rpm. The load corresponding to maximum temperature is taken as initial condition for the transient thermal analysis. From the transient analysis, heat distribution at various load steps and the time to reach the steady state are observed. Simulation results for an 6/4 SRM are presented under steady state and transient conditions. As a result, thermal analysis plays a great significance for the long term stability of the machine.