Active disturbance rejection control for the airborne pmsm in direct drive ema application

Compared with the general ball screw electromechanical actuators (EMAs), direct drive EMAs have several attractive advantages such as more reliable, efficient, accurate, and integrated due to the elimination of the intermediate gear boxes. However, the direct drive structure brings challenges to the servo control of the permanent magnetic synchronous motors (PMSMs) which are widely used in EMAs. Aiming at improving the performance of the PMSM servo system, such as wide speed range and outstanding load disturbance-rejection ability, a novel active disturbance rejection control (ADRC) is presented in this paper. To begin with, as a technique for estimating and compensating uncertainties, characteristics, and principles of the ADRC strategy are introduced in detail by comparing with PID and several advanced control strategies. Then, based on the PMSM model in d-q frame, an ADRC controller for the d-axis current is designed to implement the rotor flux linkage oriented vector control. Finally, ADRC controllers for the position and q-axis current are designed to complete the position servo control. Simulation results verify that the ADRC-based PMSM servo system is fast, precise, of no overshoot and strongly robust to load disturbance. Therefore, the ADRC strategy is feasible in the PMSM servo control and this provides necessary technical support to the direct drive EMA, which is one of the enabling technologies for the all-electric aircraft (AEA).