Transmission line breakage judging method based on electrical quantity transmission

Abstract

The invention discloses a transmission line breakage judging method based on electrical quantity transmission, comprising the following steps: S1, the opposite side of a transmission line collects the three-phase current and the three-phase voltage thereof, and sends the collected data to the local side of the transmission line; S2, the local side of the transmission line collects the three-phase current and the three-phase voltage thereof; S3, the local side of the transmission line judges whether there is a phase without current or with capacitive current on the two sides according to the three-phase currents and the three-phase voltages of the local side and the opposite side; and S4, if the same phase of the local side and the opposite side has no current or has capacitive current, that the phase of the transmission line is broken is judged. The method can help a relay protector to effectively remove a breakage fault in a high-current grounding system.

Description

technical field [0001] The invention belongs to the field of relay protection of electric power systems, in particular to a method for discriminating disconnection of transmission lines based on electric quantity transfer. Background technique [0002] In the large current grounding system, the single-phase or two-phase disconnection of the transmission line belongs to the phase failure state, which is different from the transverse fault formed by the short circuit, and belongs to the longitudinal fault. Although the disconnection fault is not as serious as the short-circuit fault, it also has a certain impact on the operation of the rotating electrical machine and the system and the relay protection. If the disconnection fault cannot be effectively removed, the line will be in a non-full-phase operation state, and the negative-sequence and zero-sequence currents that appear may cause the relay protection of the power system to leapfrog action, resulting in the expansion of ...

AI Technical Summary

Problems solved by technology

Although the disconnection fault is not as serious as the short circuit fault, it also has a certain impact on the operation of the rotating motor and the system and relay protection

If the disconnection fault cannot be effectively removed, the line will be in a non-full-phase operation state, and the negative-sequence and zero-sequence currents that appear may cause the relay protection of the power system to leapfrog action, causing the scope of power outage to expand

[0003] In the line protection devices of some foreign manufacturers, components with line disconnection monitoring function are configured, but such components depend too much on fixed values, are greatly affected by the operation of the system, and are not suitable for the current domestic operation mode. It does not meet the requirements of standardization of the fixed value of the device

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