Operating Point Resolved Loss Calculation Approach in Saturated Induction Machines

Abstract

In this paper, the global operating point dependent losses of induction machines are studied by using a local transient loss formulation. The level of flux, the machine is operated at, depends on the operation mode of the inverter. Hence, for precise loss modeling of inverter driven induction machines at the machine design stage, the time and spatial distribution of flux density and the influence of choosing the best operating point is included. A loss scaling method is developed to map iron losses calculated at a single synchronous frequency to other frequencies along the torque–speed map. The modeled losses and operating points are compared to extensive machine measurements. By way of example, the effect of different electrical steel grades tailored either to low losses or preferable magnetizability on the machine performance is investigated.