Sensorless control in switched reluctance motor drives for four quadrant operation

The present industrial and domestic applications needs the drive which is low cost, small size, reliable to different operating conditions, simple in design of controller. For a good dynamic control of any machine, knowledge of the rotor position is required. But the position sensor can be an expensive part of a drive system and because it normally be subject to a hot and electrically noisy environment, it can also be unreliable. Sensorless control is desirable, but most sensorless method involves extensive computation. This paper presents the sensorless scheme for four quadrant operation with minimal computation and simple. Eventhough due to the absence of windings in rotor the cost of machine is cheap, the torque ripple produced by the drive is more when compared to other drives due to non linearity characteristics of inductance profile. The present scheme of control predicts the position of rotor by using the phase current alone. The multiobjective function in the controller design provides the requirement of varying turn on and off angle with sampling frequency of term makes the controller very precise in every region of drives with minimum ripple content. The tracking speed of drive to get fast response in particular application like electric vehicles, wind power generator, vacuum cleaners.