ELECTRICAL-THERMAL COUPLED CALCULATION OF AN ASYNCHRONOUS MACHINE

The temperature field over the whole cross section of an asynchronous electric machine (windings, stator and rotor core, insulation, air pp) is calculated under both steady-state and transient conditions. Thermal sources (copper losses) depend on rotor slip, deep-bar effect and windings temperature. All these quantities are, in the transient condition, functions of time. The thermal part of this coupled electro-thermal process is solved by the finite element method (FEM), while the electromagnetic part is dealt with by the equivalent circuit of the asynchronous machine. The air-gap problem is specially treated. The presented method can be applied to other electric machines having negligible axial thermal heat flow.