Fault Detection and Mitigation in Multilevel Converter STATCOMs


Many static synchronous compensators (STATCOMs) utilize multilevel converters due to the following: 1) lower harmonic injection into the power system; 2) decreased stress on the electronic components due to decreased voltages; and 3) lower switching losses. One disadvantage, however, is the increased likelihood of a switch failure due to the increased number of switches in a multilevel converter. A single switch failure, however, does not necessarily force an (2n + 1)-level STATCOM offline. Even with a reduced number of switches, a STATCOM can still provide a significant range of control by removing the module of the faulted switch and continuing with (2n - 1) levels. This paper introduces an approach to detect the existence of the faulted switch, identify which switch is faulty, and reconfigure the STATCOM. This approach is illustrated on an eleven-level STATCOM and the effect on the dynamic performance and the total harmonic distortion (THD) is analyzed.


Electrical and Computer Engineering


National Science Foundation (U.S.)


This work was supported in part by the National Science Foundation under Grant ECCS 0701643.

Keywords and Phrases

STATCOM; Fault Detection; Multilevel Converter; Static Synchronous Compensator (STATCOM); Dynamic Performance; Electronic Component; Harmonic Injection; Lower Switching Loss; Multilevel Converter; Number Of Switches; Offline; Power Systems; Single Switch; Switch Failure; Total Harmonic Distortions; Fault Detection; Synchronous Machinery

International Standard Serial Number (ISSN)

0278-0046; 1557-9948

Document Type

Article - Journal

Document Version


File Type





© 2011 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Apr 2011