Abstract:

This paper investigates parameter estimation of an induction machine (IM) for torque bound construction, which is essential for trajectory planning and control in precision positioning systems. The problem differs from the well-studied one in speed-sensorless drives: speed measurement is available and all parameters in the IM model are treated as unknown. To this end, we first determine the subset of parameters required to construct torque bound, thereby avoid estimating all parameters. Then a flux-free representation of the IM model is derived to facilitate parameter estimation based on voltages, currents, and speed measurements. With the flux-free model established, a dynamic regressor extension and mixing based adaptive law is employed to ensure convergent estimation of the subset of parameters, under a less restrictive persistent excitation condition. Simulation validates the effectiveness of the proposed scheme.