Method for identifying spatial location of guide wires and aerial earth wire of power transmission line

Abstract

The invention discloses a method for identifying spatial location of guide wires and aerial earth wires of a power transmission line, and the method can be used for solving the problem that the method in the prior art is not applicable to identifying the spatial location of the guide wires and aerial earth wires of the conventional power transmission line in case of lightning shielding failures. According to the physical locations of the guide wires and aerial earth wires, the power transmission line shielding effectiveness is calculated based on the fact that the corresponding lighting shielding failure trip-out rate is zero when the exposure arc is zero, thus providing a reliable analytical method for preventing lighting shielding failures for designing and operating units, working out the shielding effectiveness of phase conductors more accurately so as to analyze the structural relations between the earth wires and guide wires to confirm the lightning protection effect of the whole power transmission line. The invention also provides a supplementary analytical method for improving the shielding effectiveness of the existing power transmission lines.

Description

technical field [0001] The invention relates to a method for determining a conductor of a power transmission line and an overhead ground wire, in particular to a method for determining the spatial position of a conductor of a power transmission line and an overhead ground wire capable of shielding lightning shielding. Background technique [0002] Lightning strikes are one of the main causes of transmission line tripping and blackout accidents. According to statistics, lightning accidents generally account for more than 50% of power system accidents. Therefore, the lightning protection design of transmission lines is of great significance to the safe and stable operation of power systems. At present, the lightning shielding system design and performance estimation of transmission lines in my country are based on the People's Republic of China power industry standard "Overvoltage and Insulation Coordination of AC Electrical Installations" DL / T620-1997. The calculation of lig...

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Problems solved by technology

The calculation of lightning shielding tripping rate in "Electric Power Industry Standard" does not consider the influence of lightning discharge process, lightning current size and ground inclination angle on shielding effect, but is a comprehensive average method based on experience and small current test model, which cannot reflect The specific characteristics of the line cannot solve the problem of shielding failure and excessive shielding tripping rate

The traditional classical electrical geometric model is an electrical geometric analysis method based on the concept of strike distance. It considers the process of lightning strikes in more detail and introduces the view that the shielding rate is related to the amplitude of lightning current. The impact of structure and lightning parameters on the shielding rate, but this method is based on the operation experience of lines with large protection angles and low tower heights. It does not consider the differences between lightning strikes on the ground, overhead ground wires, and wire positions. It is not applicable Determination of overhead ground wires for conventional transmission lines

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