On-line monitoring method and device of distribution transformer turn-to-turn short circuit

Abstract

The invention provides an on-line monitoring method of distribution transformer turn-to turn short circuit. The on-line monitoring method includes the following steps: under the no-load condition, voltage and currents of the high-pressure side of a transformer are obtained, and voltage and currents of the low-pressure side of the transformer are obtained; real-time power losses are obtained according to the voltage and the currents of the high-pressure side and the voltage and the currents of the low-pressure side; the real-time power losses are judged whether to be larger than power losses or not when the transformer works normally; if so, a first alarm signal is sent out, and if not, the first alarm signal is not sent out; and the first alarm signal is uploaded to a control center. The invention provides an on-line monitoring device of the distribution transformer turn-to-turn short circuits. The on-line monitoring device of the distribution transformer turn-to turn short circuit can carry out on-line monitoring in real time and detect failures of the transformer turn-to-turn short circuit timely. Engineering practices are relatively simple, and obvious influences on an original system and structure can not occur.

Description

technical field [0001] The invention relates to the field of safety control of transformers, in particular to an on-line monitoring method and device for interturn short circuit of distribution transformers. Background technique [0002] The normal operation of the distribution network transformer is the key to the normal operation of the entire distribution network system. In the transformer, the winding is the most important, the most complex and the most prone to failure components. Statistics show that the damage rate of the winding accounts for about 60%-70% of the entire transformer failure. The main reason for the winding fault is the inter-turn short circuit caused by the insulation failure inside the transformer. After the inter-turn short circuit occurs, the faulty winding will generate a large short-circuit current, and various losses such as heat generation will increase, which in turn will destroy the insulation and cause damage to the transformer. And for int...

AI Technical Summary

Problems solved by technology

When the transformer is short-circuited between turns, although the current in the short-circuited turns can be as high as dozens of times the rated current, the three-phase current on the power supply side is not large. Only when the fault develops to a certain extent can it be detected.

[0006] 2. For the gas relay, it can only operate when the gas accumulates to a certain minimum volume, so the inter-turn short circuit fault inside the gas protection reaction transformer is slow and takes a long time

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