High-integration transformer iron core grounding current intelligent on-line monitoring device

Abstract

The invention discloses a high-integration transformer iron core grounding current intelligent on-line monitoring device, relates to the technical field of electric power industry, and aims to solve the problems that an existing iron core grounding current on-line monitoring device is complex in structure, relatively large in external electromagnetic interference and incapable of accurately reflecting iron core grounding current data in real time during field operation and the like. According to the monitoring device, a single chip microcomputer is adopted to control a digital potentiometer toperform automatic regulation, and a single-magnetic-core double-coil iron core current transformer is adopted; and a double-stage filter and a linear power supply are adopted, so that the stability of the power supply in a strong electromagnetic interference environment is improved; two paths of correlated sinusoidal signals with the same phase correlation and the same frequency are obtained by virtue of the single-magnetic-core double-winding current transformer, the signals are input into a phase-locked amplifier, and correlation processing is carried out, so that uncorrelated noise signalscan be attenuated substantially; and then the output signals of a high precision AD phase-locked amplifier are matched to obtain the ultralow-noise current data. According to the device, the linear power supply is adopted to output + / -12V and 5V, so that a clean and stable power supply is provided.

Description

technical field [0001] The invention relates to the technical field of the electric power industry, in particular to an intelligent online monitoring device for the ground current of a highly integrated transformer iron core. Background technique [0002] The power transformer is the most important electrical equipment in the power system. Once a fault occurs during operation, it will cause serious consequences to the power system. The iron core of a transformer in normal operation is grounded at one point. If two or more points are grounded at the same time, a current loop will be formed between the iron core and the earth. The maximum current can reach dozens of amperes, which will cause the iron core to overheat or even burn out. At present, there are three main methods for judging whether there is multi-point grounding in the transformer iron core: the electrical method of regularly monitoring the grounding current of the iron core with a clamp ammeter, the method of mea...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problems of the existing on-line monitoring device for iron core grounding current, such as complex structure, large external electromagnetic interference during on-site operation, and inability to accurately reflect the core grounding current data in real time, the present invention provides an integrated transformer core grounding current intelligent monitoring device. Online monitoring device

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