A Distance Protection Method Based on Waveform Correlation under Distributed Parameter Model

Abstract

The invention discloses a distance protection method based on waveform correlation under a distributed parameter model, which includes: taking sudden change current as a protection starting element, judging that the line is faulty, and then starting the protection; Under the Bergeron line, use the voltage and current sampling values ​​at the protection installation to find the waveform correlation coefficients ρ0.6D and ρD of the fault voltage and fault component current at 60% and 100% of the line; If it is an internal fault, the protection action trips; otherwise, the protection does not operate. The present invention is based on the distribution parameter model of the transmission line, and will not be affected by the distribution characteristics of the line; the fault voltage and the fault component current are used to form the time domain protection criterion, no filtering is required, and the ability to withstand transition resistance is strong; only two points at the end of the line need to be judged The distribution trend of the waveform correlation coefficient of voltage and current can determine the fault, and the calculation amount is small.

Description

【Technical field】 [0001] The invention belongs to the field of relay protection for power system transmission lines, in particular to a time-domain distance protection method under a distributed parameter model. 【Background technique】 [0002] As a basic component of line protection, distance protection plays a vital role in the safe and stable operation of the power system. With the expansion of power system scale, EHV and UHV long-distance transmission lines are increasing day by day, and higher and higher requirements are put forward for the performance of distance protection. [0003] The existing distance protection has the following problems: the centralized parameter model is adopted, and for ultra-high voltage long lines, its distributed parameter characteristics make the measured impedance of the traditional distance protection not proportional to the fault distance, which has a great impact on the accurate calculation of the distance protection; due to the Influen...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a distance protection method based on waveform correlation under a distributed parameter model, to overcome the traditional distance protection adopting a simplified model, which is easily affected by the distributed capacitance of ultra-high voltage transmission lines; the frequency domain protection performance depends on fast and effective The filtering algorithm realizes the extraction of power frequency; and the existing distance protection algorithm requires high sampling frequency, large amount of calculation, and poor resistance to transition resistance.

Images