Speed-sensorless separately excited DC motor drive with an adaptive observer

This paper presents a speed-sensorless separately excited DC motor drive which uses the adaptive observer to estimate the rotor speed. In this paper, a stability analysis of the speed estimation is carried out. The modified feedforward control is integrated with the adaptive observer to reduce the model redundancy and to simplify the implementation. The design guideline for the feedback gain and the speed controller are also given to assure the system stability for the entire operating region. Simulation and experimental results are given to verify the validity of the proposed method.