Temperature monitoring system for an electric generator

Claim 1

Temperature monitoring apparatus for an electric generator having stator windings divided into sections through which a cooling liquid is passed and discharged to a common manifold, comprising: (A) a plurality of temperature sensors operable to provide output signals indicative of the temperature of discharged cooling liquid from respective ones of said sections; (B) means for combining all of said temperature sensor output signals for deriving an average temperature indication which may be varied by varying generator operating conditions; (C) means for initially generating and storing a correction factor for each said sensor output signal when said average temperature indication has a first predetermined value and a respective plurality of other correction factors when said average temperature indication has respective other predetermined values; (D) means for periodically sampling and temperature sensor output signals during on-line operation of said generator and deriving respective average temperature indications; (E) means response to (i) said average temperature indication derived during a sampling period and (ii) said stored correction factors to derive, for each said sensor output, an appropriate correction factor; (F) means for generating, as a result of said sampling, a relative temperature indicative value, for each said sensor output signal, based on the relationship ##EQU6## where R is said reative temperature indicative value, T is the temperature indication for a particular sensor CF is said appropriate correction factor for said particular sensor and AVG is said average temperature indication for said sampling period; and (G) means for displaying the respective relative temperature indicative values of said sensors.