Harmonic currents estimation and compensation for current control system of PMSM in overmodulation range -analysis for robustness to parameter variations-

For stability of current control system of PMSM in the overmodulation range of an inverter, many harmonic current estimation and compensation methods have been proposed. In these proposed methods, for estimating harmonic currents, the harmonic current models are used, and in these models, parameters of PMSM which are resistance, d and q axis inductances are necessary. The estimation accuracy depends directly on the accuracy of parameter values. Practically, parameter variations always occur, however the robustness of the system to these variations is still not investigated. In this paper, the robustness of estimation system to parameter variations is analyzed, and the results are confirmed by simulation and experiment.