Self tuned NFC and adaptive hysteresis based DTC scheme for IM drive

Abstract

The concept of field oriented control scheme brought the revolutionary change in industrial drives. Due to the high initial and running costs of the DC machines, the trend shifted from DC to AC motor drives to obtain high performance variable speed drives. The major achievement with field oriented control was the decoupled and independent control of stator and rotor quantities like DC machines. It is agreed that the control scheme for ac machines is complicated as compared to DC machines. The inherited problem with the ac machine control is the nonlinear relation between process variables e.g. speed and manipulated variables e.g. current, torque etc. Moreover, magnetic saturation of its rotor core causes developed torque relation of nonlinear nature.