Static and dynamic behavior of saturation-induced saliencies and their effect on carrier signal based sensorless AC drives

This paper analyzes the origin and the behavior of saturation-induced saliencies in induction machines, and their influence on carrier signal injection based sensorless techniques. The modeling of saturation-induced saliencies is necessary for the estimation of flux position, while the minimization of their influence is desired for the estimation of rotor position. Specifically focusing on rotor position estimation, there are two ways to achieve this minimization, the first being the use of a machine design that reduces the magnitude of the undesired saturation-induced saliencies and the second being the compensation in the estimator of the undesired saturation-induced saliencies. The modeling of saturation-induced saliencies, not only statically, but also dynamically, i.e. when the operating point of the machine changes, is addressed by this paper.