First experimental results of highly efficient permanent magnet synchronous machine for hybrid electric vehicle

This report constitutes the third release of a project concerning the minimization of losses of a Permanent Magnet Synchronous Machine (PMSM) for an Hybrid Electric Vehicle (HEV) and introduces the first experimental results carried out on a prototype. The focus of the research is centred on the reduction of idle loss at high speed and low load via an asymmetrical rotor design with an inductance ratio L_d/L_q >; 1. Such a characteristic feature decreases the amount of current required in the flux weakening operation and makes the engine particularly suitable for loss-minimization control strategies. An appropriate test bench as well as the necessary components to control and feed the PMSM have been set up in order to test the prototype on-load operation. The characteristic diagram of the quadrature inductance L_q and the direct inductance L_d are presented and validate the design criteria for L_d/L_q >; 1. The current trajectories of Maximum Torque per Ampere (MTPA), Maximum Torque per Volt (MTPV) and Maximum Torque per Watt (MTPW) have been determined experimentally at several speeds.