A Disturbance-Observer-Based Current Control Scheme for Five-Phase PMSM Drives with Multiple Sources of Disturbance

The current regulation performance in five-phase permanent magnet synchronous motor (PMSM) can be deteriorated by multiple sources of disturbance (e.g. rotor harmonic flux, inverter nonlinearity, dead time and parameter perturbation),which can be regarded as a lumped disturbance. Recently, plenty of the disturbance-observer-based strategies have been put forward. However, most strategies either focus on only one equivalent disturbance which consist of multiple sources of disturbance, or lack of sufficient modeling information of disturbance. Accordingly, this paper analyze the mechanism of disturbance and model several representative disturbances, and then a reduced-order disturbance observer using the internal models of disturbances is proposed to simultaneously and accurately estimate multiple sources of disturbance. In addition, a robust and effective composite control is put forward to achieve nominal performance of current regulation via a state feedback controller and reject multiple sources of disturbance by directly feeding back their estimations though control input. Comprehensive experimental results are given to verify that the proposed composite controller can suppress multiple sources of disturbance.