This paper develops the ideas of speed-and flux-sensorless sliding-mode control for an
induction motor illustrated in previous work by one of the authors. A sliding-mode
observer/controller is proposed in this paper. The convergence of the nonlinear time-varying
observer along with the asymptotic stability of the controller is analyzed. Pulsewidth
modulation implementation using sliding-mode concepts is also discussed. Major attention
is paid to torque control, and then the developed approach is utilized for speed control …

A sensorless torque control system for induction motors is developed. The system allows for
fast and precise torque tracking over a wide range of speed. The paper also presents the
identification and parameter estimation of an induction motor model with parameters varying
as functions of the operating conditions encountered in hybrid electric vehicles applications.
An adaptive sliding mode speed-flux observer is developed and a cascade of discrete time
sliding mode controllers is used for flux and current control. Simulation and experimental …