Three-current transformer on-line monitoring transformer clamp multi-point grounding current control device

Abstract

The invention discloses a multipoint ground-connection current control device for three current transformers to monitor transformer clamping parts in an online mode. The multipoint ground-connection current control device solves the problem that a power-cut current limiting operation method for ground-connection current of the transformer clamping parts in the prior art can affect normal operation of a power grid. A clamping part ground-connection outgoing line (9) penetrates through a coil of the first current transformer (10) to be connected with the input end (21) of a switching circuit, the two ends of the secondary side induction coils of the three current transformers are respectively connected with two input ports of an AD conversion port circuit, the output end of the AD conversion port circuit (15) is connected with a single chip microcomputer (17), the output end (22) of the switching circuit is connected with the ground-connection end (6), impedance units, used for limiting current impedance units, of three switching branches use bidirectional thyristors to control the branches to be turned on and off, and an impedance branch can be controlled to be turned on and off by controlling a conduction angle to achieve the purpose of switching the impedance units. The multipoint ground-connection current control device is high in operability and guarantees normal safety operation of the power grid.

Description

Technical field [0001] The invention relates to a control device for the ground current of substation equipment, in particular to a device for monitoring and regulating the ground current of a clamp in a transformer. Background technique [0002] When the transformer is in operation, an uneven electric field will be formed between the transformer windings and lead wires and the oil tank. Metal components such as the transformer core and its clips are all in this electric field. The transformer clip will generate a floating potential through the coupling of the capacitor. When the potential difference between the floating potential on the clip and the other parts in the transformer reaches a certain value, the insulation between them will be broken down and spark discharge will occur. Will burn the transformer. Therefore, the transformer clamp must be grounded effectively, and at the same time, multi-point grounding of the transformer clamp must be avoided. When the transformer ...

AI Technical Summary

Problems solved by technology

[0003] The invention provides a three-current transformer online monitoring transformer clamp multi-point grounding current control device, which solves the technical problem of affecting the normal operation of the power grid caused by the operation mode of power failure and current limiting for the transformer clamp grounding current in the prior art

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