Robust Analytical Predictive Torque Control of the Permanent Magnet Synchronous Motor

This paper presents a robust torque control strategy for the permanent magnet synchronous motor (PMSM) across the entire operating range by introducing the Robust Analytic Predictive Torque Control (RAPTC) scheme with Disturbance Observer (DOB) and Analytic Predictive Torque Control (ATPC). In the proposed predictive torque control framework, voltage reference is selected as the optimization variable to avoid model linearization and constraint approximation of the conventional methods. By formulating the problem as a one-step prediction structure, both the objective function and constraints are reduced to a quadratic intersection problem in terms of voltage. The conventional analytic solution is adopted and enables reliable and low-computation torque control by selecting the optimal solution through objective cost comparison. Also, the ψ-DOB in time-domain is suggested to resolve the fluxlinkage error in the nominal flux-map. Since the flux-map error is the dominant disturbances without the resistance error in the flux-linkage dynamics, the DOB structure can be designed to estimates the flux-map error from the estimated disturbance. To validate the feasibility and performance of the proposed torque control strategy, a numerical simulation is conducted with 4kW interior permanent synchronous motor (IPMSM).