Power transmission line broken line determining method based on semaphore transmission

Abstract

The invention discloses a power transmission line broken line determining method based on semaphore transmission; the method comprises the following steps: 1, respectively collecting three-phase voltage and three-phase current on two sides of the power transmission line, and determining whether certain-phase currentless happens on either side or not, or certain-phase as capacitance current; 2, if said conditions happen on a random side, sending the certain-phase currentless or capacitance current monitoring signals to the other side; 3, allowing the other side to receive the certain-phase currentless or capacitance current monitoring signal, determining whether the same phase has currentless condition or the same phase as capacitance current or not, and if yes, determining the power transmission line as the phase broken line. The method can help relay protection to effectively cut off broken line faults in a heavy 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 semaphore transmission. 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 the ...

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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