Time Optimal Current Control for PMSM Drives

This paper proposes an innovative current control strategy for Permanent Magnet Synchronous Motor (PMSM) drives with both isotropic and anisotropic rotors, based on Pontryagin's Time Optimal Control (TOC) theory. The control strategy assures the fastest current response after any demanded torque reference variation. It can be demonstrated that such a control exhibits faster response than hysteresis control, even if the latter is often considered the fastest control scheme. The theoretical principle of TOC is at first illustrated. It is then applied to PMSM drives and verified by simulations. Comparison to other control strategies is included in the paper. At last, an experimental validation is carried out and measured results are presented and discussed.