Efficiency Maps Computation and Comparison Including Thermal Limits

The paper presents the procedure to compute the efficiency maps of electric motors including thermal aspects, and a thorough comparison of such maps for four different machine topologies. The thermal simulations rely on the preliminary design of the cooling system, and they are later used for a fair comparison of the machine performances. In particular, some constant-temperature curves are traced in the torque versus speed plane, which identify the real thermal limits of the motors. An overload study is also performed on all the machines using the respective overload power capability, showing how the different machines compare to each other.