Two Different Approaches for Robust Adaptive Stator Current Control Strategies for Induction Motor Drives

This paper presents two different robust adaptive current control strategies for induction motor drive systems. The first approach is based on a model reference control strategy integrated to the variable structure scheme (VS - MRAC). The second is implemented by an adaptive pole placement control strategy also integrated to variable structure (VS - APPC). In the VS - MRAC, switched laws are employed for determining the parameters of the adaptive controller. In the proposed VS - APPC, the internal model principle on the reference currents is used for achieving the zero steady state tracking error of machine stator currents. Both proposed current controllers are implemented on the stator reference frame for avoiding the stator to rotor reference frame transformations. These control schemes achieve fast transient responses and robustness to parametric uncertainties. Comparison studies for determining the performance characteristics of both control approaches are presented. Experimental results are showing for determining the effectiveness of these non-standard closed-loop current control strategies.