Control dynamics of speed drive systems using sliding mode controllers with integral compensation

The authors describe the control dynamics and robustness improvement of vector-controlled AC speed drive systems using sliding mode control with integral compensation (SLMC-I). The dynamics of step command speed and impact load disturbance under SLMC-I control are formulated and studied. Acceleration estimation techniques using observers and nonideal differentiators for the SLMC-I speed drive systems are outlined and compared. The control dynamics of SLMC-I with increased system order are discussed. The techniques of robustness improvement for the SLMC-I drives are presented. A method of control in which the sliding line is fed forward is developed to enhance the drive robustness. The control dynamics with this method of control are investigated. The effectiveness of the scheme is demonstrated through computer simulations and experimental work.< >