Thermal Analysis of a Three-Phase 24/16 Switched Reluctance Machine Used in HEVs

This paper presents the thermal analysis of a 60 kW switched reluctance motor (SRM) under peak operating conditions for traction application in a hybrid electric vehicle (HEV). The SRM has 24 stator poles and 16 rotor poles, and three-phases. Heat generation losses are determined using finite element analysis (FEA) electromagnetic simulations and these losses are input into a lumped parameter thermal network (LPTN) simulation representing the thermal circuit of the electric machine. A range of coolant inlet temperatures are input and the testing of various priority operating speed points leads to the analysis of the rise in temperature of different components within the machine. By applying temperature limiting constraints of the copper windings and the rotor lamination surface, the operating times with varying coolant inlet temperatures and operating speeds can be determined.