Analysis on Low Secondary Voltage of a 220kV bus CVT

This paper summarized the defects of a 220kV busbar capacitive voltage transformer (CVT) whose secondary voltage was too low. The technical parameters and working principle of the capacitive voltage transformer were introduced. Through infrared temperature measurement, power failure diagnostic test and disintegration inspection, the causes of such problems as the low secondary voltage of the 220kV busbar capacitive voltage transformer, the excessive moisture of the transformer oil, the reduced insulation resistance of the primary and secondary windings and the large C 2 dielectric loss were analyzed, and the suggestions were put forward for the operation maintenance and defect elimination of the capacitive voltage transformer. The analysis results are of great significance to the safe and stable operation of this type of capacitive voltage transformer.