A New Detection Method of Slot Harmonics for Speed Sensorless Vector Control of Induction Motors

In general, speed sensorless vector control system has a problem that an accurate speed and the torque control become difficult when the rotational speed lowers In this paper, we propose the method to estimate the rotor speed by making a pulse and counting a slot harmonics in the negative-sequence carrier signal current method and the removal method of the saturation induced harmonics with a high-pass filter. The feature of the proposed method is to be able to extract of a slot harmonics and to remove the saturation induced harmonics with an easy circuit. The summary is shown in Table 1 about the feature of the proposal method..