Sensorless Drives in Industrial Applications

The changes in the market of motor drives over the last few years, especially the wish to complete the portfolio toward the satisfaction of most of the customer needs, have brought a new thrust in the area of drives and have favored the realization of procedures that were known from academic discussion. Under certain conditions, the injection sensorless control schemes that exploit the anisotropy of the AC machine and inject a test signal are now found in drives with permanent magnet synchronous machine, while the fundamental wave procedures seem to be the most common solution in the case of induction machines. In this paper, different aspects regarding the state of the art of sensorless drives in industrial applications and the reasons that determine the acceptance or refusal of the different solutions on the side of manufacturers of motor drives are explained and discussed.