Laboratory studies of slot discharges on stator bars

This paper is about experiments carried out on a laboratory stator mock-up comprising 6 stator bars installed in 3 different slots; some of the bars were intentionally damaged in order to reproduce slot discharges. Phase resolved partial discharge (PRPD) patterns, accompanied by simultaneous measurement of capacitance, loss tangent (tan /spl delta/) and harmonic analysis were recorded as a function of increasing voltage, from 0 to 16 kV, at steps of 500 V. Another set of results was taken after performing a repair procedure that consists in injecting s/c paint in the stator slots. Results presented here show how slot discharges affect capacitance, tan /spl delta/, Q/sub max/, harmonics and PRPD patterns and how all of these quantities are further modified after the injection of s/c paint.