Low-Complexity SVS Current-Reference Generation for PMSMs with and Without MTPV Endpoints

This paper proposes a low-complexity speed- and voltage-margin scheduled (SVS) current-reference generator for wide-speed-range permanent magnet synchronous motor (PMSM) drives. It blends current-efficient and voltage-relieving affine anchors using bounded speed and voltage-margin pressures. Unlike speed-only scheduling, the voltage term responds to torque-dependent voltage utilization and DC-link variation. A common scheduling structure covers the evaluated salient machines with and without conventional maximum torque per voltage (MTPV) endpoints. Endpoint quantities are computed offline or during initialization; the runtime candidate path uses scalar arithmetic and stored coefficients without multidimensional current-reference lookup tables, square roots, quartic solutions, or iterative optimization. Torque-consistent projection and derating enforce the modeled limits. Across three parameter sets and nine model-speed cases, SVS reduced the average RMS current-reference error from 0.8859 to 0.8041 A and the case-averaged mean effective-loss-index penalty from 9.6456% to 7.4698% relative to speed-only blending. Closed-loop Model A simulations showed comparable nominal tracking. Under a nonideal 12% voltage sag at 375 rad/s and 4.5 Nm, SVS reduced RMS speed error from 29.846 to 0.155 rad/s and saturation duration from 119.7 to 15.3 ms. Uncompensated q-axis-inductance underestimation remained the principal high-speed limitation.