Document Type

Conference Proceeding



Format of Original

8 p.

Publication Date



Institute of Electrical and Electronics Engineers (IEEE)

Source Publication

IEEE Power Electronics Specialists Conference, 2007. PESC 2007

Source ISSN



Fault tolerant operations of soft starters and adjustable-speed drives (ASDs) when experiencing power switch open-circuit or short-circuit faults are presented in this paper. The present low-cost fault mitigation solutions can be retrofitted into the existing off-the-shelf soft starters and ASDs with only minimum hardware modifications. The fault tolerant soft starters are capable of operating in a two-phase mode under the condition of thyristor/SCR open-circuit or short-circuit switch-fault in any one of the phases using a novel resilient closed-loop control scheme. The performance resulted from the present soft starter fault tolerant control has demonstrated reduced starting motor torque transient and inrush current magnitude. As for the ASDs, a low-cost fault mitigation strategy for low-speed applications such as "self-healing/limp-home" needs for vehicles and propulsion systems, with capabilities for mitigating transistor open-circuit and short-circuit switch-faults was developed. The present fault tolerant drive topology requires only minimum hardware modifications to the conventional off-the-shelf six-switch three-phase drive, with only the addition of electronic components such as triacs and fast-acting fuses. In addition, the present approach offers the potential of mitigating not only transistor switch-faults but also drive related faults such as rectifier diode short-circuit fault or dc link capacitor fault. Given in this paper is a complete set of simulation results that demonstrate the soundness and effectiveness of the present fault tolerant approaches.


Accepted version. Published as part of the proceedings of the IEEE Power Electronics Specialists Conference, 2007. PESC 2007: 1942-1949. DOI. © 2007 Institute of Electrical and Electronic Engineers (IEEE). Used with permission.

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