Experimental Parameterization of a Design Model for Flatness-based Torque Control of a Saturated Surface-Mounted PMSM*

Tailored mathematical models of permanent magnet synchronous machines (PMSMs), which systematically account for magnetic saturation and harmonics, are important for advanced nonlinear control strategies. The systematic consideration of the nonlinearities in the controller design allows to exploit the overall machine performance in the entire operating range. Physics-based models using, e.g., magnetic equivalent circuits (MECs) typically rely on details of the geometry and knowledge of the material behavior, which might not be available in many industrial applications. Hence, this paper proposes a concept to experimentally determine the parameters of a controller design model, which is derived from an MEC approach. This design model is used for flatness-based optimal torque control for surface-mounted PMSMs with significant magnetic saturation. Torque, current, and voltage measurements from different static and dynamic experiments are used to experimentally determine the optimal parameters of the model. The influence of the effective phase resistance on the accuracy is discussed and a method for a compensation is proposed. The influence of the identified parameters on the controlled PMSM is finally investigated by means of simulations of a calibrated model.