CN104991160A - Transformer winding fault detection and diagnosis method based on voltage and current characteristics - Google Patents

Abstract

A transformer winding fault detection and diagnosis method based on voltage and current characteristics. According to the method, first a capacitive coupling sensor is installed on transformer equipment and high frequency pulse signals are coupled and injected, and a response signal is measured; then fundamental components for measuring the response signal is extracted based on a short-time Fourier transform algorithm; the fundamental components that are obtained are averaged; fundamental voltage components under different winding tests are converted to 500V input voltage in a unified manner; fundamental current components under different winding tests are converted to input current in a unified manner; transformer winding characteristic parameters of long axis, short axis, slope and eccentricity are extracted; and according to the characteristic parameters and transformer winding fault cases, a contrast and an analysis are made, and whether a winding fault exists inside a transformer winding is identified. The transformer winding fault detection and diagnosis method provided by the invention can improve accuracy of detection and diagnosis of a fault of the transformer winding, and can intelligently, directly and visually determine and identify the fault of the transformer winding.

Description

Based on the transformer winding fault checkout and diagnosis method of voltage-current characteristic

Technical field

The present invention relates to Fault Diagnosis for Electrical Equipment method and technology field, particularly relate to a kind of transformer winding fault checkout and diagnosis method based on voltage-current characteristic.

Background technology

Transformer is one of most important equipment in electric system, and its stability run is great on power system security impact.Along with the increase day by day of China's net capacity, capacity of short circuit also constantly increases thereupon, and the huge electromagnetic force that the dash current that cutting-out of voltage changer is formed produces constitutes serious threat to the physical strength of Transformer Winding and dynamic stability.Therefore, winding failure has become one of main reason of transformer fault and electric power system fault, how to monitor the slight deformation of winding in transformer operational process, follow the tracks of winding state, before it occurs gross distortion, make early warning, the impact enabling them better resist the electromagnetic transient of short-circuit current and generation thereof is the key technical problem needing solution in transformer winding fault monitoring badly.

At present, when influential system does not run, the online Obtaining Accurate of the vibration frequency response curve of the further investigation network response characteristic of Transformer Winding, winding, response curve Characteristic Extraction, winding failure pattern-recognition and winding failure position and early warning thereof are most prospect and most active developing direction during following transformer winding fault is monitored.

Summary of the invention

The object of the invention is to improve the accuracy whether Transformer Winding being existed to fault, simultaneously intelligence, intuitively, visually determine and identify transformer winding fault, a kind of transformer winding fault checkout and diagnosis method based on voltage-current characteristic is proposed.

Object of the present invention is achieved through the following technical solutions:

Based on the transformer winding fault checkout and diagnosis method of voltage-current characteristic, comprise the steps:

1) capacitive couplings sensors coupled is installed to transformer equipment and inject high-frequency pulse signal, and measure response signal;

2) fundametal compoment measuring response signal is extracted based on Short Time Fourier Transform algorithm;

3) fundametal compoment asked for is averaging processing;

4) by unified for the fundamental voltage component under the different winding test input voltage being converted into 500V;

5) input current is converted into by unified for the fundamental current component under different winding test;

6) transformer winding characteristic parameter major axis, minor axis, slope and eccentricity is extracted;

7) carry out contrasting according to characteristic parameter and transformer winding fault case, analyze, identify its inside and whether there is winding failure.

The present invention by injecting high-frequency pulse signal and response signal on transformer equipment, to signal extraction, analysis, contrast, identification, since judge whether transformer equipment inside exists winding failure.Therefore, the present invention can improve the accuracy whether Transformer Winding being existed to fault, simultaneously intelligence, intuitively, visually determine and identify transformer winding fault.

Content of the present invention is further illustrated below in conjunction with accompanying drawing and example.

Accompanying drawing explanation

Fig. 1 is the transformer winding fault checkout and diagnosis method flow diagram that the present invention is based on voltage-current characteristic.

Embodiment

As shown in Figure 1, it gives the transformer winding fault checkout and diagnosis method flow diagram based on voltage-current characteristic.The inventive method comprises the steps:

1) capacitive couplings sensors coupled is installed to transformer equipment and inject high-frequency pulse signal, and measure response signal;

2) fundametal compoment measuring response signal is extracted based on Short Time Fourier Transform algorithm (Short Time Fourier Transform, STFT);

3) fundametal compoment asked for is averaging processing;

4) by unified for the fundamental voltage component under the different winding test input voltage being converted into 500V;

5) input current is converted into by unified for the fundamental current component under different winding test;

6) transformer winding characteristic parameter major axis, minor axis, slope and eccentricity is extracted;

7) carry out contrasting according to characteristic parameter and transformer winding fault case, analyze, identify its inside and whether there is winding failure.

The inventive method, for the problem of prior art, is installed capacitive couplings sensor to transformer equipment and injects high-frequency pulse signal, and measuring response signal.The fundametal compoment of measuring-signal is extracted by Short Time Fourier Transform STFT algorithm.In order to reduce external interference and the discrete impact brought of waveform, and eliminate white noise interference, the fundametal compoment asked for is averaging processing.In order to eliminate the impact of input voltage fluctuation under different winding test, unified for the fundamental voltage component under the different winding test input voltage being converted into 500V, and corresponding conversion process is done to current signal, be converted into input current by the fundamental current component unification under different winding test.Extract transformer winding characteristic parameter major axis, minor axis, slope and eccentricity, carry out contrast and analysis according to characteristic parameter and transformer winding fault case, thus reach the object of transformer winding fault being carried out to visual intelligent identification.The present invention can improve the accuracy of transformer winding fault identification, and can realize not relying on the identification of electric power expert to transformer winding fault and the problem of judgement.

Claims (1)

1., based on the transformer winding fault checkout and diagnosis method of voltage-current characteristic, it is characterized in that, comprise the steps:

1) capacitive couplings sensors coupled is installed to transformer equipment and inject high-frequency pulse signal, and measure response signal;

2) fundametal compoment measuring response signal is extracted based on Short Time Fourier Transform algorithm;

3) fundametal compoment asked for is averaging processing;

4) by unified for the fundamental voltage component under the different winding test input voltage being converted into 500V;

5) input current is converted into by unified for the fundamental current component under different winding test;

6) transformer winding characteristic parameter major axis, minor axis, slope and eccentricity is extracted;

7) carry out contrasting according to characteristic parameter and transformer winding fault case, analyze, identify its inside and whether there is winding failure.