Transformer iron core ground connection electric current monitor

Abstract

The invention discloses a transformer iron core ground connection current monitor. A current mutual inductance device inputs a detected transformer iron core current to a current-voltage transform circuit after the transformer iron core current is adjusted by a programmable gain amplifier. An output end of the current-voltage transform circuit is connected with an input end of an alternating current-direct current voltage transform circuit, and an output end of the alternating current-direct current voltage transform circuit is connected with an input end of an A / D transform circuit. An output end of the A / D transform circuit is connected with a singlechip. According to the transformer iron core ground connection current monitor, a current value of 0 to 100A can be measured, a maximum current value can be displayed, and time when the maximum occurs can be displayed. A user can conveniently master a working state of the transformer. In time of using the iron core ground connection current monitor, a single turn of a main change iron core ground connection down lead penetrates out of a hole of the top of the monitor, an original wire connection manner of a measured transformer iron core is not changed, and any potential safety hazard can not be caused on the transformer in operation. The transformer iron core ground connection current monitor has the advantages of being capable of preventing interference of electromagnetism and an electric field from the outside, high in measuring precision, accurate in numerical value, small in size, light in weight and easy to install.

Description

technical field [0001] The invention relates to the field of power transmission and transformation equipment, in particular to a transformer iron core current monitoring device. Background technique [0002] When the transformer is in operation, the electric field and magnetic field of the winding act together to make the parts of the iron core (including clamps, etc.) have different potentials. If the iron core is not reliably grounded, intermittent discharges may occur due to different potentials, damaging its Insulation; on the other hand, in order to protect the transformer device, a grounding wire is usually drawn from the transformer iron core, but when the iron core and the clamp are grounded at more than two points, each two grounding points are formed by the iron core itself and the grounding line. A closed circuit, in which the interlinked magnetic flux will induce a circulating current in the circuit, which will cause local overheating of the iron core, and in sev...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the problems of poor safety performance, low measurement accuracy, inaccurate values, and inconvenient installation of the traditional transformer core grounding current monitor, the present invention provides a transformer core grounding current monitor

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