A Sliding Observer for Robust Flux Estimation of Induction Motors and Its Characteristics

Abstract

This paper proposes a method of estimating the rotor flux using a sliding observer together with a quantitative design method of robust observer based on disturbance rejection capability in time domain. The proposed design method is valid also for the reduced-order observer, hence yields a solution to the problem of designing a robust reduced-order observer which is not clearly understood at present. It is clarified that the designed sliding observer has several advantages over the reduced-order observer. The dynamic and steady-state characteristics of the estimation error are shown to be determined by H_∞-norm of the transfer function of the disturbances.