Adaptive control of PM synchronous motor drive using VSS approach

An adaptive model-output-following controller using variable structure system (VSS) approach is proposed in this paper. Only output from the plant is needed in the VSS control law to enhance the robustness of the control system. The position control of a permanent magnet (PM) synchronous motor servo drive using the proposed control strategy is illustrated. First, an integral-proportional (IP) position controller is systematically designed according to the prescribed drive specifications of the command tracking. Next, in order to allow the given specifications to be maintained under wide operating conditions, the state-space model of the systematically designed inner IP speed loop in the nominal case is chosen as the reference model. Then, the proposed adaptive controller based on VSS theory is designed and augmented to the inner speed loop to preserve the control performance. Simulation results show that the proposed control approach results accurately model following characteristic and is robust with regard to plant parameter variations and external load disturbance.