Multipoint ground-connection current control method for three current transformers to monitor lower transformer clamping parts

Abstract

The invention discloses a multipoint ground-connection current control method for three current transformers to monitor lower transformer clamping parts. The multipoint ground-connection current control method 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 method is high in operability and guarantees normal safety operation of the power grid.

Description

technical field [0001] The invention relates to a method for controlling the grounding current of substation equipment, in particular to a method for monitoring and regulating the grounding current of a clip in a transformer. Background technique [0002] When the transformer is running, an uneven electric field will be formed between the transformer winding and the lead wire and the oil tank, and metal components such as the transformer core and its clamps are all in the electric field. The transformer clamp will generate a floating potential through the coupling effect of the capacitor. When the potential difference between the floating potential on the clamp and other components in the transformer reaches a certain value, the insulation between them will be broken down and spark discharge will occur. The transformer will burn out. Therefore, the transformer clamp must be effectively grounded, and multi-point grounding of the transformer clamp should also be avoided. Whe...

AI Technical Summary

Problems solved by technology

[0003] The invention provides a method for controlling the multi-point grounding current of transformer clamps under the monitoring of three current transformers, and solves the technical problem that the operation mode of power failure and current limiting for the grounding current of transformer clamps in the prior art causes the normal operation of the power grid to be affected

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