Design improvement of synchronous reluctance machines with internal rotor flux barriers for high-speed drives

Synchronous reluctance machines with internal rotor flux barriers can be designed to have a high saliency. Permanent magnets inserted into the rotor flux barriers considerably increase the effective saliency. The parameters of a 5 kW machine with a maximum speed of 8000 RPM for an application in a position-sensorless drive with a wide field-weakening range are evaluated by means of nonlinear finite element analyses. In addition to the normal reluctance machine, the machine with permanent magnets inserted into the rotor flux barriers is analyzed. The comparison of the characteristics of both the conventional reluctance machine and the permanent magnet assisted reluctance machine clearly shows the improved performance due to the interior permanent magnets. The main focus of the presented results is on the implementation of the machine behaviour in the control scheme of the drive.