Loop impedance method of measuring power transmission support grounding impedance and testing system

Abstract

The invention provides a loop impedance method of measuring power transmission support grounding impedance and a testing system. The loop impedance method is characterized in that S1: connection between down leads of power transmission supports or power transmission support bodies directly connected with overhead grounding wires and up wire overhead ground wires of a measured grounding device is broken; S2, all up leads of the measured grounding device are parallely connected together by using connecting wires; S3, testing current, testing voltage, and phase differences are measured; S4, a frequency conversion grounding impedance measuring device is used to calculate grounding impedance automatically according to the measured testing current, the measured testing voltage, and the measured phase differences. The invention also provides the loop impedance testing system used for measuring the power transmission support grounding impedance. The current and the voltage are measured by adopting the anti-interference frequency-selecting measurement technology, and the anti-interference capability and the data credibility of the measurement are greatly improved.

Description

technical field [0001] The invention relates to measuring methods, in particular to a loop impedance method and a testing system for measuring the grounding impedance of transmission towers. Background technique [0002] The tower grounding of the transmission line is the most important link in the transmission line, and it is one of the indispensable measures to prevent lightning hazards. In order to ensure the safe and stable operation of the power transmission system, reducing the grounding resistance of the tower is the main measure to improve the lightning withstand level of the line and reduce the tripping rate of the line due to lightning strikes. [0003] Lightning tripping of overhead transmission lines has always been a problem that plagues the safe power supply of the power grid. In recent years, with the development of the power grid, tripping and blackout accidents caused by lightning strikes on transmission lines are increasing. According to the classification...

AI Technical Summary

Problems solved by technology

Its shortcoming is that it is necessary to arrange the test lines of the current electrode and the voltage electrode on the site, which increases the work intensity of the site. In some mountainous areas, the wire release path of the pole tower is very complicated or even impossible to find the wire release path; at the same time, the voltage is extremely impossible. Arranged at infinity, the existence of the current pole will inevitably distort the current field, which will bring errors to the measurement

The disadvantage is that because the measurement signal is a high frequency and small current, the reliability of the measurement data is low, and for the test circuit with certain inductance, the equivalence is poor

[0013] (4) Different-frequency high-current method: The large-scale ground network measurement system with different frequency and high-current can output 10A level 45-55Hz different-frequency sine wave current, which can improve the signal-to-noise ratio, improve the anti-interference ability, high measurement accuracy, and the results are real and reliable. However, its technology is complicated, its volume and weight are large, it needs an AC power supply, and it is inconvenient to use in the field

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