Detecting interturn short circuits in rotor windings

Abstract

The problem of detecting and locating shorted turns in rotor windings has always been a difficult technological challenge. The winding is completely embedded in the steel, and the turn insulation is not physically loaded until it is subjected to the centrifugal forces produced at rated speed. The problem of detecting shorted turns appears to be very cumbersome. A technique proposed by the Electric Equipment department of Mexico's Electric Research Institute provides the data, at rated rotor speed, to locate the short-circuited windings and the number of short-circuited turns. This technique improves the sensitivity and dependability by means of a statistical process applied to the signal provided by the search coil.