System and method for judging frequency-selective filter performance of transformer winding deformation tester

Abstract

The invention discloses a system and method for judging the frequency selection filtering performance of a transformer winding deformation tester, and the system comprises a signal generator which outputs a sine interference signal with the known frequency and amplitude value; an adder which carries out the adding of an output signal of a tester which is in a single-frequency-point detection mode and is used for a sine signal with the known frequency, and an output signal of the signal generator; an attenuator which carries out the attenuation of the output signal of the adder, and transmits the attenuation signal to a response signal detection port of the tester. The system enables the frequency selection filtering band attenuation requirements to be changed into gain requirements, carries out the comprehensive determination of the frequency selection filtering characteristics through a detection result of the tester, and indirectly represents the quality of the frequency selection filtering characteristics of the filter through an error value of gain detection, so as to solve a problem that a conventional system needs to disassemble or damage a tester during the detection of the frequency selection filtering performances.

Description

technical field [0001] The invention relates to the field of transformer fault detection, in particular to a method for judging the frequency selection filter performance of a transformer winding deformation tester. Background technique [0002] The transformer is the core equipment of the power grid. Winding deformation is one of the most common internal faults of power transformers. Under the action of electrodynamic force and mechanical force, the size or shape of the winding changes irreversibly. After the local deformation of the winding, even if it is not damaged immediately , It is also possible to leave serious hidden troubles. "Twenty-Five Key Requirements for Preventing Major Accidents in Electric Power Production" and "Eighteen Major Anti-Accident Measures for Power Grids of the State Grid Corporation" put the transformer winding deformation test in a very important position, and stipulated that the frequency response method test winding deformation is 110 ( 66) ...

AI Technical Summary

Problems solved by technology

In order to meet the on-site test and reduce the influence of other frequency signals on the test results, its anti-interference ability, that is, the frequency selection filter performance, that is, the ability to filter out interference signals other than the frequency sweep signal, is the basic functional requirement of the tester. Although it has been mentioned in the power industry standard "DL / T911-2004 Frequency Response Analysis Method for Power Transformer Winding Deformation", there is no corresponding calibration method to scientifically evaluate and judge this performance index

[0005] In order to determine the frequency selection filter performance of the tester, a spectrum analyzer is generally used for testing. However, the sweep signal output and response signal detection of the tester are integrated inside the instrument, and the filter performance test at the response signal detection end needs to be disassembled or destroyed.

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