Adaptive disturbance observer-based parameter-independent speed control of an uncertain permanent magnet synchronous machine for wind power generation applications

This paper proposes a parameter-independent speed controller based on the classical cascade speed control strategy comprising an inner-loop current controller and an outer-loop speed controller for permanent magnet synchronous machines. The contribution of this paper is three-fold: the first is the proposal of a parameter-independent current controller in the inner loop with global asymptotic stability guarantee; the second is the presentation of a guideline for choosing stabilizing proportional-integral (PI) gains in the outer loop; and the third is designing an adaptive disturbance observer (ADOB) to predict the one step ahead state, so that this predicted state compensates the one-step time delay on the control input. The effectiveness of the proposed controller is demonstrated by simulating a wind power generation application using powerSIM (PSIM) software.