Design and iron loss analysis of sensorless-controlled interior permanent magnet synchronous motors with concentrated winding

This study investigates the influence of the stator configuration of low-speed sensorless-controlled interior permanent magnet synchronous motors (IPMSMs) with concentrated winding on the sensorless drive feasibility and iron loss. To evaluate the sensorless controllability of the motors, a mathematical and simulation process of estimating the rotor position error is proposed. In addition, the harmonic iron loss under a load condition is analysed via two-dimensional non-linear finite element analysis. Considering both the sensorless drive feasibility and iron loss, the four different IPMSMs, which have different tooth tip configurations in the stator, are examined. It is shown that the machine with a relatively short and thin stator tooth tip has better sensorless drive controllability and lower harmonic iron loss than the others. Based on the analysis result, a final model applied with stator chamfer for electric vehicle traction is proposed and manufactured. The validity of the simulations and the design method are verified by the experiments.