Robust adaptive stator current control for an induction machine

In indirect rotor flux oriented vector control of an induction machine the performance is highly dependent on the current control loops. In this paper, a new robust adaptive current control scheme for the induction machine is proposed. For synchronous frame current control, a pole placement controller (PPC) is designed by employing the internal model principle (IMP) resulting in zero steady state tracking error of the machine stator currents. The dead-zone technique is utilized in the gradient adaptive law to enhance the robustness of the control system. A projection operation is also constructed to assure that the machine parameter estimates are within their permitted range. Simulation results are presented showing the effectiveness of this new closed-loop current control system compared to the traditional proportional-integral controller.