Crossover line permanent fault recognizing method for double circuit lines on same tower

Abstract

The invention discloses a crossover line permanent fault recognizing method for double circuit lines on a same tower. The crossover line permanent fault recognizing method comprises the steps of: 1. judging whether an amplitude of a difference of voltage at tripping phase ends of different circuit lines is less than or equal to a voltage setting value after the double circuit lines on the same tower have crossover line faults, if so, executing a step 4, if not, executing a step 2; 2. judging whether a phase of the difference of the voltage at the tripping ends of the different circuit lines is more than or equal to a setting phase after the double transmission lines on the same tower have the crossover line faults, if so, executing the step 4, if not, executing a step 3; 3. when the double circuit lines on the same tower have the crossover line temporary faults, reclosing by the tripping phases in delay, and ending a process; and 4. when the double circuit lines on the same tower have the crossover line permanent faults, interlocking reclosing, and ending the process. According to the crossover line permanent fault recognizing method provided by the invention, through analyzing whether the double circuit lines on the same tower have the crossover line faults, according to the characteristics of the voltage at the tripping phase ends after fault phases trip, whether a line operates in a light load or a heavy load, the crossover line permanent faults are effectively identified, and thus success rate of reclosing the line can be effectively increased.

Description

technical field [0001] The present invention relates to the field of electric power generation, transmission and distribution, and in particular to a method for identifying permanent faults across double-circuit lines on the same pole. . Background technique [0002] The distance between EHV and UHV double-circuit transmission lines on the same pole is relatively short, and cross-line faults may occur. Operation experience at home and abroad shows that the probability of cross-line faults accounts for about 10%-20% of the total faults. Although the proportion is not high, once it overlaps with a permanent fault, it will cause both lines to jump and seriously affect the system. reliability of power supply. [0003] Overhead line faults are mostly transient, as are cross-line faults [1]. If the nature of the fault can be identified before reclosing, the reclosing will start when there is a transient fault, and the reclosing will be locked when there is a permanent fault, th...

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Problems solved by technology

[0005] For double-circuit lines on the same pole, the existing technology still uses the method of judging the nature of single-phase ground faults of single-circuit lines based on the voltage of the phase terminal, combined with the method of reclosing according to the phase sequence, and there is no practical criterion for cross-line faults Appeared [3], which made it impossible to identify the nature of the cross-line fault of the double-circuit line on the same pole in the prior art, which greatly increased the probability of the double-circuit transmission line on the same pole overlapping with the permanent fault across the line, and further increased the The risk of causing damage to the stability of the power system will seriously affect the continuity and reliability of power supply.

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