Recent Development of Predictive Encoderless Control for AC Motor Drives

Abstract: Encoderless control for AC motor drives is an important technique to improve system reliability and reduce hardware cost. In recent years, fundamental/high frequency model-based observers, accompanied with vector control technique, has accomplished numerous advances and has been partially applied in industry areas. However, a single fundamental/high frequency model-based method cannot achieve full speed operation, requiring the combination of two methods. Recent studies have shown that predictive control has the potential to replace additional pulse-signal injection because it can accurately determine the output voltage pulse sequences, which can obtain the position information of the salient pole motor by detecting the current slope. This keynote aims to introduce the recent development of predictive encoderless control for AC motor drives. In addition to the expected combination of predictive control and pulse signal injection method, the combined predictive control with fundamental frequency model method will also be introduced.