Generator stator winding diagnostic system

Diagnostic apparatus for diagnosing the winding system of an electrical generator having a plurality of coil sections with internal first and second vent tube stacks through which a cooling gas is passed, comprising:

• (A) monitoring means for monitoring the temperature of cooling gas emerging from said first and second vent tube stacks of selected ones of said coil sections and operable to provide corresponding first and second temperature indicative signals;
• (B) diagnostic computer means being responsive to said first and second temperature indicative signals and operable to generate therefrom corresponding first and second normalized temperature indicative signals;
• (C) said diagnostic computer means being further operable to test said normalized signals to see if they fall below, within or above a normal range and to generate respective confidence factors in the existence of a said signal being below, within or above said normal range;
• (D) said diagnostic computer means being responsive to said confidence factors and operable to generated respective confidence factors in the existence of various predetermined combinations of said signals below, within or above said normal range;
• (E) said diagnostic computer means being responsive to said confidence factors in the existence of said predetermined combinations to generate respective confidence factors in the existence of predetermined abnormal conditions as a function of the existence of various ones of said combinations;
• and
• (F) means for communicating said latter confidence factors together with their corresponding abnormal condition indication, to an operator.