Sensorless Control of EESM Based on Adaptive Interconnected Observer

In order to solve the problem of rotor angle identification of electrically excited synchronous motor(EESM), this paper proposed a rotor position identification method based on an adaptive interconnected observer for nonlinear model. Firstly, an expansion model of EESM was established; Secondly, the model was separated into two interconnected subsystems and feedback gain for subsystems was designed respectively. Thus, an adaptive interconnected observer can be obtained. Lastly, Lyapunov stability theorem was used to prove the stability of the proposed method. The method can obtain the speed, position angle and q axis inductance according to the measured voltage and current signals, and the identified information was feedbacked to the control loop to further optimize the control performance. The simulation results show that the method can achieve stable accurate operation on a wide speed range in the electric state and power generation state, and the identification of q-axis inductance value can be quickly and accurately followed the real value. The experimental results further proved the effectiveness of the proposed method. © 2017, The editorial office of Transaction of China Electrotechnical Society. All right reserved.