Speed sensorless control performance improvement of induction motor drive using uncertainty cancellation

An improved spccd estimator using paraiiicter uncertainty cancellation and its application to an indirect tield-oriented induction motor drive arc presented. First, the speed estimation errors of a V-l model-based adaptive speed observer due to parameter variations are analysed. Then, accordingly, a novel compensation scheme is dcvclopcd to cancel the effects of parameter variations on the estimated spccd pcrformance. A variable structure system controller, with the dctcctcd error signal as its input, is employed to realise the proposcd compensation scheme. Finally, the robust speed control with quantitative control pertʹorniancc considcring the effect of de;id-time enlargement due to the feedback of estimated speed is presented. Theoretic bases of the proposed spccd estimator and the robust spcecl controller are derived in detail, and their validities are dcnionstrated by some simulation and measured results.