Sensorless control of SRM using magnetizing curves

Among various variable speed drives, switched reluctance motors (SRMs) have been found to be competitive with traditional ac and de motors because of their simple construction and drive electronics. However, the necessity of using a shaft-mounted position sensor is one of the drawbacks of the SRM from the standpoint of cost, size, and reliability. Position sensorless SRM drives are expected to solve these problems. This paper presents a method of position sensorless control based on a simple fuzzy model of nonlinear position-dependent magnetizing curves. The sensors needed for the drive are one voltage sensor and one current sensor. Experimental studies using a 1.5-kW, 5400-rpm SRM with a 6/4 tooth configuration show that the maximum error of rotor position estimation is less than three mechanical degrees in the 1:20 speed range under any load conditions. (C) 2001 Scripta Technica.