Complete stability of reduced-order and full-order observes for sensorless IM drives

Lennart Harnefors, Marko Hinkkanen

    Research output: Contribution to journalArticleScientificpeer-review

    157 Citations (Scopus)


    In this paper, reduced-order observers for flux and speed estimation of sensorless induction-motor drives are analyzed. All gain selections, which give stability for all operating conditions, including the regeneration mode (called complete stability), are found. Furthermore, it is shown that full-order observers, under the assumption of fast stator-current dynamics, have equivalent implementations as reduced-order observers. Consequently, all gain selections of the full-order observer gains for which complete stability is obtained, under the assumption stated, are also found. A number of previously proposed full-order observers are analyzed within the developed framework, generally showing agreement between the full- and reduced-order models.
    Original languageEnglish
    Pages (from-to)1319-1329
    Number of pages11
    JournalIEEE Transactions on Industrial Electronics
    Issue number3
    Publication statusPublished - 3 Mar 2008
    MoE publication typeA1 Journal article-refereed


    • induction-motor drives
    • observes
    • sensorless control


    Dive into the research topics of 'Complete stability of reduced-order and full-order observes for sensorless IM drives'. Together they form a unique fingerprint.

    Cite this