CHARACTERIZATION AND ANALYSIS OF UNKNOWN FOREIGN POWDER IN THE GENERATOR STATOR WATER COOLING SYSTEM

To solve the problem of abnormal temperature rise of generator stator slots, unknown foreign powder in the 300MW generator stator water cooling system was characterized and analyzed by SEM and EDS. The experimental results showed that the unknown foreign powder in generator stator cooling water tank was mainly ion exchange resin, ferric oxide, calcium carbonate as well as silica gel and sediment introduced from outside while the unknown powder mixture in the filter was mainly ferric oxide and calcium carbonate. The abnormal rising temperature of stator slots is due to unknown foreign powder blocking the hollow copper conductor of the generator stator. Moreover, counter measurements for solving the problem were tentatively put forward and the practical data and scientific basis for the long-term security and stability operating of large generators were thus provided.