Calculation method for transmission line clearance spatial synthetic electric field under mountain fire condition

Abstract

The invention discloses a calculation method for a transmission line clearance spatial synthetic electric field under a mountain fire condition. According to the method, the height, temperature and form of a flame are obtained according to a typical vegetation burning test, a stable burning area is selected, and clearance below a transmission line is divided into a flame body equivalent area and a gas-solid two-phase body area; a difference moving particle sizing instrument is adopted to measure small particles, a vernier caliper is adopted to measure big particles, and the statistical law of particle volume concentration and particle size is obtained; the electric quantity qk of the particles in the flame is calculated; a simulation model is established, and a finite volume method is utilized to solve transient temperature distribution and fluid motion; simulation calculation is performed on particle movement in the flame clearance to obtain particle distribution in the flame clearance; particle positions and carrying capacity are set, and a finite element method is utilized to solve a spatial synthetic electric field to obtain electric fields E at different positions; and initial particle distribution and an initial electric field value are set, temperature-fluid-particle movement-electric field multi-field coupling calculation is performed, and a final spatial synthetic electric field is obtained. The method can provide a basis for research on the discharge mechanism and breakdown characteristics of clearance.

Description

technical field [0001] The invention discloses a method for calculating a synthetic electric field in a gap space of a transmission line under a mountain fire condition, and relates to the research field of discharge mechanism and breakdown characteristics of a transmission line gap under a mountain fire condition. Background technique [0002] The corridors of transmission lines are increasingly tense, and transmission channels inevitably pass through areas with high forest fire risk with lush vegetation. Wildfires may cause tripping accidents due to the decrease of phase-to-phase and phase-to-phase insulation strength of transmission lines. According to statistics, in recent years, there have been hundreds of tripping accidents in my country's power grid due to wildfires. In the spring of 2014 alone, lines above 220kV in the State Grid were affected by wildfires for 47 times of emergency shutdown, 17 times of step-down operation, and 213 times of withdrawal Reclosing has se...

AI Technical Summary

Problems solved by technology

[0003] Particles and ashes in the flame are charged under the influence of ions in the flame, and enter the gap under the transmission line under the action of airflow and electric field force to form a particle chain, which distorts the space electric field and causes partial discharge, further causing the entire gap to break down

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