A method for estimating ground lightning density near a high-speed railway viaduct contact network system

Abstract

The invention discloses a method for estimating ground lightning density near a high-speed railway viaduct contact network system, which comprises the following steps of firstly, determining a systemresearch space, and establishing a high-speed railway viaduct overhead line system lightning fractal development model by combining a lightning fractal theory on the basis of calculating a spatial electric field by a finite difference method and a super-relaxation iteration method; simulating the established model for many times; obtaining the number of lightning times and corresponding coordinates of the ground near the high-speed railway viaduct; on the basis, using a least square polynomial fitting method or carrying out curve fitting on the viaduct height, obtaining a function relational expression of a fitting coefficient and the viaduct height, and finally obtaining a function expression of the ground lightning density and ground coordinates near the viaduct and the viaduct height. The estimation method provided by the invention can estimate the lightning strike density of the ground near the high-speed railway contact network system in a lightning environment, and has a certainguiding significance for the placement of important equipment near a viaduct, so as to reduce the probability that the important equipment is struck by lightning.

Description

technical field [0001] The invention relates to the technical field of power system overvoltage, in particular to a method for estimating the lightning density on the ground near the catenary system of a high-speed railway viaduct. Background technique [0002] After the tall viaduct catenary system is built, because it is much higher than the ground and has a large size, it can affect the electric field distribution around the high-speed railway within a certain range, and has strong lightning characteristics, which may affect the distribution of ground lightning. To a certain extent, the distribution of ground lightning strikes directly determines the probability of ground buildings and equipment being struck by lightning, and even threatens personal safety. Therefore, it is of great theoretical significance and engineering value to study the influence of viaduct catenary system on ground lightning distribution. [0003] At present, the research on lightning strikes of tal...

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Problems solved by technology

In terms of high-speed railways, although many domestic scholars have conducted a lot of research on its lightning characteristics, among them, the high-voltage technology "Lightning Protection System for High-speed Railway Traction Power Supply System" in the 39th issue of 2013 and the high-voltage technology in the 41st issue of 2015 "Comprehensive Evaluation of Lightning Protection Effect of Elevating PW Line or Erection of Lightning Protection Line" is based on the particularity of the catenary system to study its lightning protection characteristics, and puts forward certain protection measures, such as raising the PW line and serving as a lightning protection line or separately The lightning protection scheme of erecting lightning protection lines, but none of the above studies involve the ground lightning near the building, but based on the above research results, it can be known that the tall buildings on the ground will change the lightning strike path, which will affect the distribution of ground lightning near the building to a certain extent

[0004] In addition, the above research applied two lightning strike models: Electrical Geometric Model (EGM) and Pioneer Propagation Model (LPM). The propagation model only considers the certainty of lightning development, but does not consider the randomness of lightning development

The 36th issue of high voltage technology in 2010, "Transmission Line Lightning Protection Analysis Fractal Model and Its Statistical Characteristics", although it involves the impact of transmission line erection on the distribution of ground lightning, but the transmission line and catenary system regardless of voltage level, line erection height, Conductor types, system structures, materials, etc. are all very different. At the same time, the above research uses statistical methods and pilot development models, and fails to give the specific characteristics of the ground lightning distribution before and after erection.

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