Motor State Augmented Full-state Feedback DC-Link Voltage Control for Two-stage PMSM Drive

A control method based on the motor state augmented full-state feedback (MSAFSF) control including motor state variables for front-end converter of two-stage PMSM drive is proposed in this paper. The DC-link voltage is adjusted according to the dynamics of the motor. To meet quick speed changes of the motor, rapid voltage response of the DC-link is needed. Therefore, the control strategy of the front-end converter is very important. In this paper, a DC-DC buck converter is adopted as the front-end converter of a two-stage PMSM drive. Usually, only the state variables of the converter are considered in the full-state feedback (FSF) control of the front-end converter while using the linear quadratic regulator (LQR) to design controller parameters. When the motor is accelerating, DC-link voltage and quadrature-axis current oscillate. Hence, the state variable matrix of the proposed MSAFSF control is augmented by motor state variables, so that the load variations such as the current drawing during the motor acceleration could be considered in the feedback control. As a result, the oscillations of the DC-link voltage and quadrature-axis current are reduced. The computer simulations and hardware experiments verify the validity of the proposed MSAFSF control.