Online monitoring device and method of grounding current of iron core of transformer

Abstract

The invention provides an online monitoring method of grounding current of an iron core of a transformer, and the method comprises the following steps: (1) sheathing a straight-through current transformer on a grounding wire of the iron core of the transformer for getting a primary iron core grounding current signal; (2) utilizing the straight-through current transformer to convert the acquired primary current signal into a secondary current signal and converting the secondary current signal into a voltage signal; (3) performing gear position switching and amplification treatment on the voltage signal, and further sending the signal to an AD (analog / digital) circuit arranged in a controller via a voltage signal conditioning circuit; and comparing with a pre-set alarm threshold, and using the controller to control a display screen to display an alarm signal when the signal is abnormal; and (4) on the one hand, displaying the signal after calculation treatment in the step (3) through the display screen, on the other hand, storing measurement result and measurement time in a FLASH memory. The method is widely suitable for online monitoring of the grounding current of the iron cores / clamping pieces of the transformers, reactors and other electrical equipment.

Description

technical field [0001] The invention belongs to the field of transformer on-line monitoring, and relates to an intelligent on-line monitoring device for transformer core grounding current and transformer clip grounding current, in particular to an on-line monitoring device for transformer core grounding current and a monitoring method thereof. Background technique [0002] The power transformer is one of the key equipment in the power system, and it is also a link with a high failure rate in the power equipment. Its normal operation is an important guarantee for the safe, reliable, high-quality and economical operation of the power system. When the power transformer is in normal operation, one and only one point of the iron core must be reliably grounded. Once the iron core is grounded at two or more points, a circulating current will be generated inside the iron core, causing local overheating, and in severe cases, it will cause local burning of the iron core. Even the grou...

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Problems solved by technology

[0005] Purpose of the invention: The present invention provides an online monitoring device for transformer iron core grounding current, the purpose of which is to solve the problem that it is difficult to ensure the accuracy and accuracy of the measurement data in the previous method of monitoring the transformer iron core grounding state in the operating state and Regular inspections cannot guarantee timely detection of multi-point grounding faults in the iron core

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