Efficiency aspects of vector control applied to synchronous reluctance motors

Core losses in a synchronous reluctance machine are modelled. The empirical model obtained is used to implement a control scheme to compensate for equivalent core loss currents. This enables accurate control of the magnetising currents, hence torque. Efficiency over the base speed operating range of the machine is compared for two different vector control schemes. Methods of triplen series injection for vector controllers are discussed and a new method proposed. The new technique has advantages in terms of overall triplen content and computational requirements. Inductance ripple in the machine is estimated using direct torque ripple measurements and incorporated in a machine model valid for low speed operation.