A Diagnosis Method of Transformer Winding State under Sudden Short Circuit

Abstract

The invention discloses a method for diagnosing the winding state of a transformer under sudden short circuit, which comprises the steps of (1) carrying out real-time short circuit monitoring on the transformer, acquiring continuous vibration signals of the wall of a transformer box every time when sudden short circuit is detected to occur in the transformer, and calculating energy distribution of a Hilbert energy spectrum of the vibration signals acquired every time when sudden short circuits occurs in the transformer through a method described in steps (2)-(5); and (6) judging the winding state of the transformer according to energy distribution Md of the Hilbert energy spectra H2(omega, t) of the vibration signals x0(t) acquired in two adjacent times when sudden short circuit occurs in the transformer, and determining that looseness or deformation occurs in the winding of the transformer when variations of the energy distribution Md of the Hilbert energy spectrum H2(omega, t) of the vibration signals acquired in the last time when sudden short circuit occurs in the transformer exceeds more than two times of the previous energy distribution. According to the method disclosed by the invention, the operating state of the transformer winding can be judged accurately and efficiently.

Description

technical field [0001] The invention relates to a signal monitoring method, in particular to a method for diagnosing the state of a winding when a sudden short circuit occurs in a transformer. Background technique [0002] Transformer is one of the most important equipment in the power system, and its operation stability has a great influence on the safety of the power system. With the increasing capacity of my country's power grid, the short-circuit capacity is also increasing, and the deformation of transformer windings caused by external short-circuits has remained high. posed a great threat. [0003] After the transformer suffers a sudden short circuit, its winding may loosen or be slightly deformed first, and the deformation of the transformer winding has a cumulative effect. The anti-short-circuit capability of the transformer is greatly reduced. At this time, even a small short-circuit surge current may cause a major accident. [0004] On the one hand, the deformati...

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Problems solved by technology

[0016] The test sensitivity of the frequency response method is higher than that of the short-circuit impedance method. However, due to the complexity of the frequency response waveform, the judgment of the winding condition requires more experience, and it is difficult to form a clear quantitative criterion. Therefore, no criterion has been formed so far.

[0017] The starting point of the above two methods is to measure and judge the transformer winding according to the change of its electrical parameters. This is more suitable for the obvious deformation of the transformer winding, but it is suitable for the slight deformation of the winding, especially for the transformer winding. Relatively loose and twisted deformation state can not give a clear judgment

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