A new sliding-mode based control design for induction motors propelling electric vehicle drives

In this paper, a variable structure controller based on sliding-mode design is proposed for induction motors that propel electric vehicle drives. The underlying design concept is to endow the closed loop system with high performance dynamics for all possible speed ranges while maximizing power efficiency and keeping the required stator currents within the inverter ceiling limits. The proposed approach is based on a new variable structure control switching surface derived from a nonlinear formulation of sliding surfaces. With the proposed nonlinear variable structure, the exponential stability of the inner loop is guaranteed and insensitivity to uncertainties and disturbances are achieved as well. The robustness, accuracy, fast dynamic response and wide speed-range operation of the drive using the proposed control approach is demonstrated by computer experiment results.