A post-test simulation method for transformer internal fault identification based on coupled inductor port characteristics

A technology of internal faults and port characteristics, applied to electrical components, emergency protection circuit devices, etc., can solve problems such as numerical vibration, complex parameter identification methods, etc.

Active Publication Date: 2016-09-14
KUNMING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, any protection that uses the two electrical quantities of current and voltage needs to know the parameters of the windings on both sides of the transformer, and a complex parameter identification method needs to be introduced, which is likely to cause numerical vibration and other problems.

Method used

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  • A post-test simulation method for transformer internal fault identification based on coupled inductor port characteristics
  • A post-test simulation method for transformer internal fault identification based on coupled inductor port characteristics
  • A post-test simulation method for transformer internal fault identification based on coupled inductor port characteristics

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0077] Implementation Mode 1: The structural diagram of a 38.5 / 525kV double-winding three-phase step-up transformer is as follows figure 1 , the transformer parameters are as follows: the three-phase transformer is connected by three single-phase transformers, the transformer ratio is 38.5 kV / 525 kV, the leakage inductance on both sides is 0.524mH, the winding resistance is ignored, and the sampling frequency is 20 kHz. A single-phase ground fault occurs at the transformer secondary side bus outlet (such as figure 2 Middle k1 point), the transition resistance is 50Ω.

[0078] (1) In the time window of 5ms, measure the voltage u of the primary side outlet terminal and the secondary side outlet terminal of the transformer respectively 1 , u 2 and current i 1 i 2 , using the equivalent circuit under normal operating conditions of the transformer to calculate the analog voltage

[0079] (1)

[0080] Then compare the measured voltage u at the outlet of the secondary si...

Embodiment approach 2

[0082] Implementation Mode 2: The structural diagram of a 38.5 / 525kV double-winding three-phase step-up transformer is as follows figure 1 , the transformer parameters are the same as in Example 1.

[0083] A single-phase ground fault occurs in the secondary side winding of the transformer (such as figure 2 Middle k2 point), the transition resistance is 50Ω.

[0084] After a fault occurs in the power transmission system, the voltage at the outlet of the secondary side of the transformer is simulated and calculated according to the same method as in Example 1 , and then compare it with the measured voltage The degree of similarity of the waveforms (eg Figure 4 ), calculate the analog voltage and measured voltage The correlation coefficient of the waveform r = -0.6028 <0, so it is judged as a fault in the transformer area.

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Abstract

The invention relates to a post-measurement simulation method for transformer internal fault identification based on coupling inductance port characteristics, and belongs to the technical field of transformer relay protection. When a fault occurs in the transmission system containing a transformer, the voltages at the primary and secondary outlets of the transformer are measured in a short time window. u 1 、u 2 and current i 1 、 i 2 , according to the electromagnetic coupling relationship of the transformer, simulate and calculate the voltage at the outlet terminal of the secondary side , and then the analog voltage at the secondary side outlet terminal and measured voltage u 2 Comparing the waveforms of the two waveforms, the correlation coefficient of the two waveforms is calculated r , according to the similarity of the two waveforms, that is, the correlation coefficient r The size of the transformer identifies whether an internal fault has occurred. The invention can correctly and quickly identify whether an internal fault occurs in the transformer, is not affected by the excitation inrush current, has high sensitivity and good reliability.

Description

technical field [0001] The invention relates to a post-measurement simulation method for transformer internal fault identification based on coupling inductance port characteristics, and belongs to the technical field of transformer relay protection. Background technique [0002] As more and more ultra-high voltage long-distance transmission systems are built and operated in my country and UHV transmission systems under construction are put into operation, there will be an increasing number of large-capacity ultra-high voltage and ultra-high voltage transformers in the system, which will affect the reliability and protection of transformer protection. Rapidity puts forward higher requirements. According to the data, the current correct action rate (70~80%) of transformer protection for 220kV and above is far lower than that of line protection (99.07%), so further research, development and improvement of transformer protection are urgently needed. [0003] In transformer diffe...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02H7/045
Inventor 束洪春张兰兰蒋彪
Owner KUNMING UNIV OF SCI & TECH
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