A new flux and stator resistance identifier for AC drive systems

The effect of stator resistance on AC drive performance is analyzed for flux vector and indirect field-oriented controllers. A new technique-the back electromagnetic force (BEMF) detector-for reducing the adverse effects of stator resistance on field-oriented control is presented and evaluated through simulation and experimental results. The BEMF detector is shown to reduce the impact of the stator resistance variations and also provide an estimate of the stator resistance. The detector is compatible with most control strategies and with or without position feedback.