Transformer core grounding fault treatment and matters needing attention

Transformer core earthing fault treatment and matters needing attention - 2019 03 - 30 15:05:37 1, transformer core multipoint earthing fault processing transformer core multipoint earthing faults, in most cases is caused by suspended solids in the formation of conductive bridge under the influence of electromagnetic field. In this case, will use the capacitor discharge impact method to deal with. Capacitor charge and discharge circuit, the circuit of capacitance C for about 50 mvar, arrester dc voltage output voltage of about 1 kv. Use of the method is: first of all, the two-way switch K close to contact 1 side, the capacitance C charging, charging after rapid switch K close to contact 2 side of transformer core fault point discharge, breakdown can be repeated several times. If it is a ground fault of other property, by capacitance discharge impact law, it is difficult to rule out general crane cover inspection process. 2, oil transformer iron core transformer core fault processing oil way short circuit fault in the general case cover handle, must be conducted after hoisting cover open iron core level connections between conductors, multimeter resistance measure oil way short circuit, then can use thin wood planks in oil duct pilot conduction, the short circuit property to launch oil. If the above methods can not achieve, and do not have core dissolution conditions, only changing the connection method of core level indirectly by way in parallel to serial. When using parallel grounding method, between the core level ground lug is inserted in the intermediate position of the core per level. And using series grounding method, ground lug is inserted at the edge of the iron core oil duct ( General oil and 3 piece of silicon steel sheet apart) 。 To sum up, this paper argues that the transformer core earth fault problems still need to pay attention to the following aspects: ( 1) Transformer core oil way short circuit fault in the general case cover handle, must be conducted after hoisting cover open iron core level connections between conductors, multimeter resistance measure oil way short circuit, then can use thin wood planks in oil duct pilot conduction, the short circuit property to launch oil. ( 2) If the above methods can not achieve, and do not have core dissolution conditions, only changing the connection method of core level indirectly by way in parallel to serial. ( 3) Found that core multipoint earthing faults on the gas chromatography can be used to track and monitor grounding current monitoring.