A Fast On-Line Diagnostic Method for Open-Circuit Switch Faults in SiC-MOSFET-Based T-Type Multilevel Inverters

Jiangbiao He, Nabeel A.O. Demerdash, Nathan Weise, Ramin Katebi

Research output: Contribution to journalArticlepeer-review

79 Scopus citations


On-line condition monitoring is of paramount importance for multilevel power converters used in safety-critical applications. A novel on-line nonintrusive diagnostic method for detecting open-circuit switch faults in silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs)-based T-type multilevel converters is introduced in this paper. The principle of this method is based on monitoring the abnormal variations of the dc-bus neutral-point current in combination with the existing information on instantaneous switching states and phase currents. Advantages of this method include faster detection speed and simpler implementation compared to other existing diagnostic methods in the literature. Moreover, this diagnostic method is immune to the disturbances of inverter's dc-bus voltage unbalance and load unbalance. In this method, only one additional current sensor is required for measuring the dc-bus neutral-point current; therefore, the implementation cost is low. Simulation and experimental results based on a lab-scale 20 kVA adjustable speed drive with a three-level SiC T-type inverter validate the effectiveness and robustness of this novel diagnostic method.

Original languageEnglish
Article number7805177
Pages (from-to)2948-2958
Number of pages11
JournalIEEE Transactions on Industry Applications
Issue number3
StatePublished - May 1 2017

Bibliographical note

Publisher Copyright:
© 1972-2012 IEEE.


  • Fault diagnosis
  • T-type multilevel inverter
  • neutral-point current
  • open-circuit switch faults
  • silicon carbide (SiC) metal-oxide-semi-conductor field-effect transistor (MOSFET)

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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