Direct-current transmission line fault online positioning terminal, method and system

Abstract

The invention provides a direct-current transmission line fault online positioning terminal, method and system. The terminal comprises an open-type magnetic ring, a high-frequency pulse generator, a non-contact sensor and a conversion device, the open-type magnetic ring and the high-frequency pulse generator are both connected to a neutral point of the direct-current power transmission coupling capacitor, and the non-contact sensor and the conversion device are installed on a first-stage tower at an outlet of a converter station. According to the invention, the reliability of fault positioningis greatly improved, the precision is less influenced by the length of the direct-current transmission line and the excessive resistance of the fault, and the positioning precision is improved. According to the invention, the direct-current transmission line is segmented through the plurality of distributed fault online positioning terminals, so that the length of the direct-current transmissionline is indirectly shortened. According to the invention, the fault type is identified, the corresponding fault online positioning is selected based on different fault types, the precision is high, and the online positioning of the high-resistance fault is realized.

Description

technical field [0001] The invention relates to the technical field of power system automation, in particular to an online fault location terminal, method and system of a direct current transmission line. Background technique [0002] In recent years, HVDC transmission has developed rapidly in my country, and fault location of HVDC transmission lines is of great significance for the rapid elimination of HVDC transmission line faults, the restoration of power supply, and the safety and stability of the power grid. Transmission line fault location can be divided into active location method and passive location method in principle. The passive location method uses the steady-state or transient components generated by the fault to complete the fault location. The passive location method can automatically complete the location analysis after the fault because it does not require the cooperation of one-time equipment. It is the main location method used in practical engineering. ...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the disadvantages of low reliability in the above-mentioned prior art and the accuracy is greatly affected by the length of the DC transmission line and the excessive fault resistance, the present invention provides an online fault location terminal for DC transmission lines. The terminal includes an open-type magnetic ring, a high-frequency Pulse generator, non-contact sensor and conversion device; open magnetic ring, connected to the neutral point of the DC transmission coupling capacitor, used to construct the traveling wave boundary; high-frequency pulse generator connected to the neutral point of the DC transmission coupling capacitor , used to inject the generated high-frequency pulse signal into the DC transmission line based on the traveling wave boundary; the non-contact sensor is installed on the first-stage tower at the exit of the converter station to collect the analog voltage signal of the DC transmission line; the conversion device is installed On the first-stage pole tower at the exit of the converter station, it is used to convert the analog voltage signal into a digital voltage signal and send the digital voltage signal, which not only greatly improves the reliability of fault location, but also the accuracy is limited by the length of the DC transmission line and The influence of excessive fault resistance is small, which improves the positioning accuracy

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