A NovelFault Detection ofanOpen-Switch Fault in theNPCInverter System

Inthispaper, a simple fault detection schemeis proposed forimproving thereliability undertheopen-switch fault ofathree-level neutral point clamped (NPC)inverter. Thefault of switching deviceisdetected by checking thechangeofa pole-voltage inaNPCinverter. Thismethodhastheadvantages of fast detection ability andasimple realization forfault detection, comparedwithexisting methods.Reconfiguration isalso performed bytwo-phase control methodthatusedtosupply the balancing three-phase powertotheloadcontinuously. This proposed methodminimizes abadinfluence ontheloadcaused by adelay offault detection. Thismethodcanalsobeembedded into theexisting NPC inverter systemasa subroutine without excessive computational effort. Theproposed schemehasbeen verified bysimulation andexperimental results.