Sensorless control of AC machines using high-frequency excitation

In the present paper a new method for sensorless control is presented, which can handle the presence of multiple non-separatable saliencies. Because of the inimitability of the measured impedance curves, the method is based on the minimum error between the measured curves during operation and precommissioned reference curves. The method can handle alternating and rotating test signals. The capacity of the proposed method is tested on two different standard induction machines, which are not especially designed for sensorless control. Operation at standstill, and even at zero-frequency, is possible.