PURPOSE: To easily diagnose the occurrence of abnormality in a sealed oil-immersed transformer in real time and deterioration of the transformer by only continuously detecting the concentrations of H2, CO, and CO2 in the air enclosed in the transformer and diagnosing them based on the detected concentrations.
CONSTITUTION: The gas detecting chamber 3 of a detecting section (a) is equipped with a gas sensor 1 for H2 and another gas sensor for CO and CO2 and is always communicated with the air 9 enclosed above oil in a transformer through a valve 13. The section (a) is connected 4 to a diagnosing section (b). The H2, CO, and CO2 generated by the deterioration of insulating paper in a coil 10 dissolve in insulating oil 11 and, at the same time, are diffused in the air 9 and come to exists in a certain ratio in an equilibrium state between the air 9 and oil 11. From the volume of the air 9 and quantity and temperature of the oil 11 related to the ratio, the generated gases in the air 9 are detected with the sensors 1 and 2. An arithmetic processor 6 calculates the concentrations of the gases in the oil by amplifying the electric signals from the sensors 1 and 2 and diagnose the occurrence of abnormality or deterioration based on deterioration discriminating reference values. When the concentrations exceeds the reference values and the occurrence of abnormality or deterioration is discriminated, an alarming buzzer 7 and lamp 8 are actuated.
KAWACHI FUMIO
YAMAOKA MASAYOSHI
NISHIMURA TAKESHI
KURIYAMA TADASHI
KANSAI TEC KK
DAIHEN CORP