DEVELOPMENT OF DETECTION METHOD WITH A MAGNETIC-FIELD SENSOR FOR INCOMPLETE CONTACT IN GAS-INSULATED SWITCHES AND BUS CONNECTING PARTS

This paper describes a detecting method of incomplete contact in gas i nsulated switches and bus connecting parts. The principle of the metho d is to measure the change in magnetic field caused by the current dis tribution at an abnormal contact point. Fundamental studies with small -size bus models have shown that incomplete contact can be reliably de tected with an opto-magnetic sensor in the case of aluminum enclosures . A feasibility study was also conducted for a full-scaled 300kV GIS s tructure with more realistic incomplete contact conditions.