Analysis of stator iron loss in interior PM machines under open and short-circuit conditions

This paper describes an analytical approach for calculating the stator iron loss for multiple-barrier interior permanent magnet (IPM) machines with distributed windings, under open and short-circuit (deep field-weakening) conditions. It is based on using a lumped equivalent-circuit model to predict the rotor mmf and then the harmonic components of the airgap flux density. A “filter function” approach is used to calculate the stator tooth and yoke flux densities and hence iron loss components. It provides an insightful means for visualizing the effect of stator and rotor design changes on the stator iron losses. The analytical stator iron loss predictions for four IPM machine configurations are compared with finite element results.