Improvement of Postfault Performance of Multiphase Drives in Terms of Operating Region and Stator Copper Loss Conference Paper uri icon


  • © 2018 IEEE. Multiphase drives are particularly attractive for safety-critical applications, due to their enhanced fault tolerance. Most of the faults in electric drives occur in the power electronics. Switch faults can be divided into open- and short-circuit ones. The conventional techniques to handle switch faults in two-level converters mainly consist in either keeping the corresponding phases open or connecting the stator terminal to the dc-link midpoint through a triode for ac (TRIAC). However, the former results in lower maximum torque and larger stator copper loss (SCL), whereas the latter leads to a reduction in the maximum speed and has not been considered in the context of two-level multiphase drives. This paper proposes to adequately combine these approaches in two-level multiphase drives, depending on the speed, the faulted switches and the neutral configuration, so that the total operating region of the drive is extended and the SCL is decreased, when compared to the conventional strategies. It is also shown and exploited that, for multiphase drives based on multiple three-phase winding sets, turning on or off a TRIAC placed between their neutrals as a function of the speed allows further improvement of the postfault performance. Simulation results are provided to confirm the theory.

author list (cited authors)

  • Yepes, A. G., Doval-Gandoy, J., & Toliyat, H.

citation count

  • 3

publication date

  • October 2018