Overload Performance Prediction of PM and Synchronous Reluctance Machines for Traction Applications

This paper proposes several methods to compare the overload performance of different types of synchronous machines for electric traction applications. An ideal model to predict the performance of the motor at high overload condition is introduced. In the simplified analytical saturation model, the saturation flux linkage is a parameter. This allows the performance prediction as a function of three normalized parameters: magnet flux linkage, unsaturated inductance and saliency ratio.The other main part of the work concerns the machines analysis using the finite element approach. Models with different levels of accuracy and generality show the possibility of reducing the number of simulations in the d- and q-axis currents plane to obtain the full performance prediction. Machines with different level of cross saturation are considered to test the proposed models.Simulation results of the studied approaches are compared with the prediction obtained from the full machine mapping using finite element analysis, in which a large number of evenly spaced points in the (id,iq) plane are analyzed to derive the working characteristics.