Novel partial-discharge-free oil guide box structure

Abstract

The invention discloses a novel partial-discharge-free oil guide box structure. The novel partial-discharge-free oil guide box structure comprises an oil guide box, a hand hole flange welded to the upper surface inside the oil guide box and an oil box covering plate in threaded connection with the hand hole flange through a hexagon socket countersunk head screw, a slope is formed between the upper surface and the lateral side of the oil guide box through two 135-degree bent structures, and first hand hole openings are formed in the slope at intervals in the direction of the horizontal middle line of the slope. Second hand hole openings corresponding to the first hand hole openings are formed in the inner side of the hand hole flange, second thread holes are formed in the periphery of the face, in contact with the oil guide box, of the hand hole flange, and a neck is formed in the edge of the outer side of the face, in contact with the oil guide box, of the hand hole flange. First thread holes corresponding to the second thread holes are formed in the periphery of the surface of the oil box covering plate. According to the novel partial-discharge-free oil guide box structure, when an induced voltage test is carried out on an extra-high voltage transformer, the medium-voltage partial-discharge amount can be controlled to range from 20 pC to 30 pC and is basically a background partial-discharge amount, and safe running of the transformer can be guaranteed.

Description

technical field [0001] The invention relates to an auxiliary part of a transformer oil tank, in particular to a novel non-partial discharge oil guide box structure. Background technique [0002] In large-capacity super- and extra-high voltage AC contact transformers, generator transformers and converter transformers, the cooling method is generally required to be OFAF or ODAF. In order to reduce the oil flow velocity of the body and prevent the oil flow from being electrified, the transformer oil tank is usually designed with an oil guide box structure, and at the same time, a slag cleaning port is set on the oil guide box, and it is sealed with a cover plate. When the oil tank is designed, the sealing cover and the oil guide box are connected by M10 slotted countersunk screws. After the cover is fastened, the upper parts of the M10 slotted countersunk screws are lower than the upper surface of the cover. Considering the long-term operation of the transformer, the M10 slott...

AI Technical Summary

Problems solved by technology

Considering the long-term operation of the transformer, it is possible that the M10 slotted countersunk screw may become loose due to the vibration of the transformer, and the area where the oil guide box is often located Lead wires with high current and high voltage pass through. Once the screws are loose, a floating potential will appear, which will easily generate partial discharge, which will affect the safe operation of the transformer.

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