Single-ended-data-based multi-segment distance protection method and system of high-voltage direct-current line

Abstract

The invention relates to a single-ended-data-based multi-segment distance protection method and system of a high-voltage direct-current line. The method comprises: voltage and current information at relay protection device installation locations of p-pole and n-pole lines of a direct-current transmission system are collected and the collected information is sent to respective signal processing units of all segments of protection units of the two poles of lines to carry out low-pass filter processing with different cutoff frequencies; according to line parameters and measurement signals after filtering of all segments of protection units, compensation voltages of set points of all segments of protection units of the two poles of lines are calculated; and ratios of the compensation voltages of set points of all segments of protection units of the two poles of lines to corresponding filtered measurement voltages of the segments are calculated and internal and external faults in the high-voltage direct-current line zone are determined based on the negative or positive state of the ratios. The criterion is simple; the reliability is high; and the set basis does not rely on simulation; and thus a series of problems that the existing high-voltage direct-current line protection is lack of clear setting basis and the reliability is low are solved.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, and more specifically relates to a method and system for multi-stage distance protection of high-voltage direct current lines based on single-ended measurement. Background technique [0002] In recent years, HVDC transmission projects have developed rapidly in my country. HVDC transmission has the advantages of large transmission capacity, low line loss, and easy access to distributed energy sources. However, since HVDC transmission systems are usually used to transmit electric energy over long distances, they will inevitably face various harsh weather and natural environments. Therefore, its transmission lines are extremely prone to failure. However, the existing HVDC transmission line protection has various deficiencies, such as high sampling rate requirements for traveling wave protection, imprecise theory, susceptible to lightning interference, difficult wave ...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the above defects or improvement needs of the prior art, the present invention provides a method and system for multi-stage distance protection of high-voltage DC lines based on single-ended measurement, thereby solving the lack of clear setting basis, sampling A series of technical problems such as high rate and low reliability

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