Overhead transmission line lightning stroke current monitoring method and lightning stroke fault recognition method

Abstract

The invention provides a novel overhead transmission line lightning stroke current monitoring method and a novel line lightning stroke fault recognition method which are easy to implement. The technical scheme comprises an inversion algorithm for lightning stroke current of the tower top and a ground wire at the center of the tower span of a lightning struck overhead transmission line, a lightning stroke fault type recognition method and a line lightning stroke probability observation and lightning leading width calculation method. The technical scheme provided by the invention has important application values for improving the lightning performance and the risk evaluation level of the overhead transmission line, optimizing the line lightning protection design and improving the line lightning protection level.

Description

technical field [0001] The invention relates to the application field of power grid safety and protection in a power system, in particular to a lightning strike current monitoring method and a lightning strike fault identification method for an overhead transmission line. Background technique [0002] The monitoring work specifically aimed at lightning strikes on overhead transmission lines began in the 1950s: in order to obtain the distribution of lightning current amplitudes on transmission lines, the amplitude of lightning overvoltages on lines, the rod rate, the shunt coefficient of towers, and lightning tripping, etc., the Soviet Academy of Sciences About 140,000 magnetic steel recorders and nearly 7,000 electric spark meters are installed in the power system, such as figure 1 The lightning monitoring method of the former Soviet Union line shown. In three years, a total of about 1350 lightning current records were obtained, which provided valuable information for the f...

AI Technical Summary

Problems solved by technology

Through the operation experience and theoretical analysis of the lightning location system for many years, it is found that due to factors such as the highly undulating terrain on the earth's surface, the absorption and refraction of electromagnetic waves by the atmosphere, and the electrical properties of the soil, the electromagnetic waves radiated by lightning travel in the propagation path of the atmosphere. , The wave velocity has changed, and it has caused the attenuation and distortion of the lightning pulse. At present, the average positioning error of the lightning positioning system is between 0.5km and 2km, and the measurement error of the lightning current cannot be determined. According to this, most of the world The lightning current amplitude and waveform monitoring data of the country that has not adopted the lightning location system

[0012] In view of the limitations of the lightning location system, my country has carried out a series of other lightning current monitoring and exploration work on transmission lines in recent years, such as the use of traveling wave positioning devices installed at both ends of the line and fault recording and distance measuring devices. For fault location, the lightning strike current of the line cannot be monitored; in addition, a lightning rod is installed at the horn of the top of the line and a Rogowski coil is used to monitor the lightning strike current at the top of the tower. The lightning current measured by the positioning system is used for calibration, such as Figure 5 As shown, this method cannot directly judge the type of lightning strike fault on the line; there is also a real-time monitoring device for lightning strike current of the transmission line that installs a Rogowski coil on the low-voltage end of the line insulator string and the ground wire support of the tower, which can realize line counterattack and shielding fault discrimination and line Lightning current monitoring, such as Image 6 As shown, similar to the principle of the American tracker, the premise of realizing the line counterattack and shielding fault discrimination function is to assume that the lightning flashover of the line occurs along the insulator string

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