Implementation of generic sensorless direct field oriented control of AC motors on a low-cost, fixed-point digital signal processor

This paper presents an implementation of low cost, generic sensorless direct field oriented (GSDFO) control algorithm applicable to both induction (IM) and permanent-magnet synchronous motors (PMSM). The proposed algorithms are simple but maintain good performance over a normal speed operation. The stator flux is derived based upon the improved integration of back electromotive force (EMF), effective over a wide range of speed. The synchronous speed is simply calculated from the back EMF and stator flux whereas a slip is computed for IM additionally. The overall system is implemented in a TMS320LF2407EVM based controller for low cost. Experimental results are presented to verify the proposed algorithm.