Methods of stator winding on-line diagnostics for large turbine generator preventive maintenance

The introduction of on-line diagnostic methods is a mandatory condition for the transition from the existing maintenance system to a preventive maintenance system. This paper analyses the methods of early detection of the most common defects in stator windings of large turbine generators with water cooling. The detection of overheating and leaks in the winding is described. The examples are given in which the detection of these defects and their repair prevented failures with heavy consequences.