Flux Estimation for Speed Sensorless Rotor Flux Oriented Controlled Induction Motor Drive

摘要

A new flux estimation algorithm for speed sensorless rotor flux oriented controlled induction motor drive is proposed. In the proposed method, a new state is defined which when introduced makes the right hand side of the conventional motor model independant of the unknown terms containing rotor flux and speed. A new motor model is derived after introducing the newly defined state assuming zero time derivative of rotor speed which allows speed estimation without requiring the knowledge of mechanical parameters of the drive system. The estimation algorithm is based on observing this newly defined state which is used for estimating both the rotor flux and the speed. Rotor flux estimation is achieved using a modified Blaschke equation obtained after introduction of the new state into the Blaschke equation or commonly known as the current model; while, speed is computed using a simple equation obtained using this new state.