A high-voltage direct current line fault detection method, system, device and storage medium

Abstract

The invention discloses a high-voltage direct current line fault detection method, system and device. The method includes the following steps: obtaining high-voltage direct current transmission line parameters in real time; calculating a fault detection start criterion according to the high-voltage direct current transmission line parameters, and calculating compensation variation when the fault detection startup criterion is established; A DC control compensation current is obtained from the DC current; a fault identification criterion is established according to the DC control compensation current, and the fault type of the HVDC transmission line is determined by using the fault identification criterion. The present invention compensates the influence of the DC control characteristic on the fault DC current by compensating the change amount when a fault occurs on the high-voltage direct current transmission line, highlights the characteristics of the fault direct current, thereby accurately detecting and identifying the fault of the high-voltage direct current transmission line, and the direct current The fast backup protection of the line is of great significance. The invention can be widely applied in the technical field of electric power system relay protection.

Description

technical field [0001] The invention relates to the technical field of relay protection of power systems, in particular to a high-voltage direct current line fault detection method, system, device and storage medium. Background technique [0002] The High Voltage Direct Current (HVDC) system is widely used in modern power systems due to its characteristics of high-power long-distance transmission. At present, in actual engineering, the single-ended protection of fault initial traveling wave is used as the main protection of HVDC lines, including traveling wave protection and differential undervoltage protection. Although the traveling wave protection operates quickly, its ability to withstand transition resistance is poor. When a high-impedance ground fault occurs, the traveling wave protection is not sensitive enough. It needs the current differential protection as a backup protection to identify the fault DC current. Due to the distribution Due to the influence of capacit...

AI Technical Summary

Problems solved by technology

Although the traveling wave protection operates quickly, its ability to withstand transition resistance is poor. When a high-impedance ground fault occurs, the traveling wave protection is not sensitive enough. It needs the current differential protection as a backup protection to identify the fault DC current. Due to the distribution Due to the influence of capacitive current, DC control characteristics and AC faults outside the inverter side, the traditional current differential protection has the characteristics of low setting value and long delay, which makes the fault DC current exist for a long time in the DC control transient stage and is difficult to remove

The root cause is that the fault DC current is affected by the DC control characteristics, which weakens the fault DC current characteristics to varying degrees, thereby reducing the protection's operating performance.

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