DSP-based adaptive fuzzy control for a sensorless PMSM drive

A study on DSP-based PMSM (permanent magnet synchronous motor) drive without the encoder sensor is presented in this work. In the sensorless technique, a flux angle estimator mainly constructed by a sliding mode observer is utilized to estimate the back electromotive force (EMF) and the flux angle, and indirectly compute and the rotor speed of the motor. These estimated values are feedback for vector control in the current loop and for speed control in the speed loop. To increase the performance of the speed controller, an adaptive fuzzy controller (AFC) consisted by a fuzzy controller, a reference model and an adjustable mechanism is applied; after that, the rules of the fuzzy controller can be online updated in real time. Finally, the TMS320F2812 DSP (digital signal processor) is adopted to implement the aforementioned controllers. Combined a sensorless technique and an adaptive control technique into the speed controller of a PMSM drive make its performance be improved, the cost be reduced and the reliability be increased.