Distribution line single-phase grounding traveling wave protection method

Abstract

The invention provides a distribution line single-phase grounding traveling wave protection method. The method includes: step 102, respectively acquiring fault zero modal initial current traveling wave within a frequency range of 0-100KHz and fault zero modal initial voltage traveling wave within a frequency range of 0-100KHz, comparing wavefront polarity of the fault zero modal initial current traveling wave with that of the fault zero modal initial voltage traveling wave, and enabling a first criterion to be established when the polarity of the fault zero modal initial current traveling wave and the polarity of the fault zero modal initial voltage traveling wave are opposite; step 104, acquiring three-phase current magnitude and zero-sequence voltage magnitude under the condition that the first criterion is established, and enabling a second criterion to be established if the zero-sequence voltage magnitude is larger than a first setting value and the three-phase current magnitude is smaller than a second setting value; and step 106, judging to determine that a single-phase grounding fault occurs and giving out a trip signal or an alarm signal when the first criterion and the second criterion are both established. By the technical scheme, when the single-phase grounding fault occurs in a distribution line neutral point ineffective grounding system, the fault can be detected quickly and accurately, and reliable protection actions can be taken.

Description

technical field [0001] The invention relates to power system protection and control technology, in particular to a traveling wave protection method for single-phase grounding of distribution lines. Background technique [0002] In the course of more than 100 years of continuous development of the power system, the single-phase grounding protection problem of the neutral point non-effective grounding system has been puzzling scholars at home and abroad. When a single-phase ground fault occurs in this system, the circuit can only be formed through the capacitance to ground, and the fault current is very small. It has brought great difficulties to the composition of protection. [0003] The traditional methods mainly focus on further excavating the fault information of the steady-state current after the fault, and put forward such as jumping method, zero-sequence reactive power method, zero-sequence admittance method, and negative-sequence current method. Sequence active powe...

AI Technical Summary

Problems solved by technology

However, the above research is mainly based on the high-voltage transmission network, and there is no relevant report on the application of the principle of traveling wave protection in the distribution network.

At the same time, because high-frequency noise interference, lightning waves, operating waves, etc. have the same characteristics as fault traveling waves, traveling wave protection is generally considered to be less reliable

[0006] Therefore, there is a need for a single-phase ground traveling wave protection method suitable for distribution lines with high reliability, which overcomes the insensitivity or failure of traditional protection methods due to the ineffective single-phase ground fault phenomenon of the neutral point non-effective ground system. defect, improve the sensitivity and reliability of single-phase ground fault protection

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