Showing papers by "Giuseppe Buja published in 1993"

Variable structure control of an SRM drive

Abstract: The applications of a variable-structure system (VSS) to the control of a switched reluctance motor (SRM) drive is presented. After reviewing the operation of an SRM drive, a VSS-based scheme is formulated to control the drive speed. The scheme is then designed and tested by simulation. The results show that the VSS control is effective in reducing the torque ripple of the motor, compensating for the nonlinear torque characteristics, and making the drive insensitive to parameter variations and disturbances. >

Disturbance torque estimation in a sensorless DC drive

Abstract: The estimation of the disturbance torque in a sensorless DC drive is carried out by extending the classical observer theory. Three estimation schemes are formulated according to the representation of the disturbance torque and processing of the observer states. In addition to the disturbance torque, all the schemes deliver an estimation of the motor speed. Steady-state accuracy and dynamics of the schemes are analyzed in nominal conditions, identifying the scheme with the best performance. The effects of variations in the motor parameters are also analyzed, finding that a proper modeling of the motor makes the steady-state estimation of the disturbance torque insensitive to any variation. As a test, the schemes are applied to a sensorless DC drive for both compensating for the disturbance torque and closing the speed loop. The responses obtained with the best-performance scheme are reported. >