Saturation Modulation in Voltage Zero Sequence-Based Encoderless Techniques - Part II: Implementation Issues

Recent articles demonstrate that sensorless drives for induction motors can operate at zero electrical and mechanical frequencies with the aid of high frequency signal injection techniques and processing the zero sequence voltage signal. The paper presents some practical implementation issues affecting the performance of such a technique and shows how to improve the quality of the estimated angle. All the assessments are experimentally proved and have a general value that can be extended to other sensorless techniques injecting high frequency signal