A Novel Weight Function and Interpolation Method for the Field Weakening Strategy of a Synchronous Reluctance Machine

In this paper a new field weakening strategy is proposed for the torque control of a synchronous reluctance machine. The control strategy does not require any machine parameters. It uses an interpolation method between the MTPA-and MTPV-trajectories to move along a path, which is very similar to that of the constant torque contour lines. It also reduces the copper losses in the field weakening region. The strategy uses look-up tables for the trajectories determined from measurement results and does not require any additional cascade controller. Hence the stability and the dynamic of the current controller are not degraded. The control strategy is validated experimentally using an 11kW synchronous reluctance machine.