Transformer core multi-point earthing fault testing device

Abstract

The invention discloses a transformer core multi-point earthing fault testing device. The device mainly comprises a transformer, a fault simulation module, a communication conversion module, a computer and a box. A transformer core is a wound core, an excitation winding is wound on the core, 12 earthing wires are led out from different positions in the core and connected with the fault simulation module, instructions are sent out through the computer, and the on-off state of a relay on the fault simulation module is controlled through the communication conversion module so as to be connected or disconnected with the ground. Multi-point earthing fault testing of the core at different positions can be conducted, the amplitude of faulty current is monitored, and influences of ground resistance on fault conditions are researched. The testing device is simple in structure, accurate and reliable in detection, convenient to operate and very suitable for on-site application.

Description

technical field [0001] The invention belongs to the field of electric equipment fault detection, and more specifically relates to a test device for multi-point grounding faults of transformer iron cores. Background technique [0002] Transformer is one of the important equipment of power system, and its normal operation affects the safety and reliability of power system. According to relevant statistical data, the accidents caused by multi-point grounding of iron core rank the third in the total accidents of transformers, so the multi-point grounding fault of transformer iron core cannot be ignored. When the transformer is in normal operation, in order to prevent the floating potential of the core to the ground, resulting in intermittent breakdown of the core to the ground, the core must be reliably grounded at one point, but when more than two points of the core are grounded, the unevenness between the cores The potential will form a circulation between the grounding point...

AI Technical Summary

Problems solved by technology

[0003] At present, the multi-point ground fault of transformer core and its diagnosis work are all based on the laminated core transformer. The laminated core is formed by stacking silicon steel sheets insulated from each other, and the coiled core is formed by winding silicon steel strips. There are obvious differences in the structure of the iron core, so when a multi-point ground fault occurs, the magnitude of the fault current and the influence of the ground resistance on the fault situation will have a large difference; and for the multi-point ground fault of the transformer core and its diagnosis work, most It is to connect the grounding wire at a fixed place to simulate the multi-point grounding of a certain point of the iron core, and it is impossible to analyze the multi-point grounding fault of the iron core at multiple positions and points

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