The paper aims to estimate the thermal impact of temperature dependency of material characteristics on induction machines, for which a coupled electromagnetic thermal analysis is carried out.
Both electromagnetic and thermal fields are calculated using a weak coupled finite element analysis algorithm. The electromagnetic behavior of the induction motor is obtained by coupling the field equations to the voltage equations of the windings. The nonlinearity due to the saturation of the iron core and the temperature dependency of the electrical conductivity are taken into account. When the heat sources are evaluated the temperature distribution in the induction motor is obtained. In order to improve the accuracy of the formulation, thermal contact resistances, external and internal convection are considered.
The results presented in this paper prove that the temperature dependency of electric material characteristics must be considered, to accurately simulate the behavior of the induction motors during the design stage.
The presented field‐circuit coupling completes the two‐dimensional finite element analysis by introducing the possibility to take into account the three‐dimensional part of the motor (Rtête, Ltête). Another advantage is the ability to include voltage sources. Consequently, a realistic approach for the electromagnetic and thermal behavior of the electrical machine is achieved.
