Postfault operation of a nine-phase six-terminal induction machine under single open-line fault

Ahmed M. Massoud, Shehab Ahmed, Ayman Samy Abdel-Khalik*, Mostafa S. Hamad

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


This paper studies the postfault control of a nine-phase six-terminal induction machine (IM) during single open-line fault, which was recently proposed for high-power medium-voltage applications as a promising alternative to conventional six-phase IMs. The required optimal reference currents to provide prefault loading conditions under one-line open are derived using the two most common optimization criteria employed in multiphase drives, namely, maximum torque and minimum loss modes. A postfault controller, based on conventional decoupling Clarke's transformation, is then used to ensure the same controller structure under all conditions. Consequently, the machine characteristic curves, achievable torque, and stator copper losses under these different modes are compared. A comparison with a conventional asymmetrical six-phase winding is also given. A 1.5-Hp prototype IM is used for experimental verification.

Original languageEnglish (US)
Article number2733471
Pages (from-to)1084-1096
Number of pages13
JournalIEEE Transactions on Industrial Electronics
Issue number2
StatePublished - 2017


  • Asymmetrical winding
  • Fault-tolerant operation
  • High-power induction machine (IM)
  • Nine-phase machine
  • Single layer winding
  • Six-phase machine

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering


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