Rotor Speed Detection Method for Vector Control of Induction Motor without Speed Sensor Utilizing Slot Harmonics

摘要

Speed sensorless vector controlled induction motor drives are the standard choice in many industrial applications, but this can hardly control torque and rotor speed at low speed. Recently, a method based on high-frequency signal injection has been studied. This paper presents a method for suppressing the effects of the saturation saliency by using a high-pass filter, and a new approach to estimate the rotor speed. The effectiveness of these methods is demonstrated through experimental results showing both good suppression of saturation harmonics and good sensorless speed control at low speed.