Safety assessment system and method for two-phase grounding surrounding environment of transmission lines under layered soil

Abstract

The invention discloses a system and method for evaluating safety of two-phase grounding surrounding environment of a power transmission line under layered soil. The system comprises a power module, aline module, a step voltage test module, an experiment box and a data analysis module. A power-frequency power supply is connected with the line module through a three-phase outgoing line. Three phases of lines are connected with a three-phase RLC load through line resistors, broken line simulators and a load transformer. The broken line simulator comprises current sensors, high-voltage switches,a current acquisition device, a switch action judgment device, a central processor and a wireless transceiver device, and is used for simulating two-phase broken line ground fault of the power transmission line. The step voltage test module is used for measuring the step voltage under the layered soil. The data analysis module is responsible for operation and control of the other modules and records relevant parameters. The system and method can effectively simulate the two-phase broken line ground fault of the power transmission line under the horizontally stratified soil, and can effectively evaluate the step voltage to evaluate safety of the surrounding environment.

Description

technical field [0001] The invention belongs to the technical field of electric power system grounding, in particular to a safety evaluation system and method for the surrounding environment of two-phase grounding of transmission lines under layered soil. Background technique [0002] The two-phase short-circuit ground fault of the transmission line of the distribution network is very harmful to the power system. When a two-phase ground fault occurs, there will continue to be high potential and potential gradient near the ground point. A potential difference is generated between the feet, resulting in a step voltage electric shock accident. The step voltage will cause great harm to the human body. In mild cases, the skin and organs will be burned and scars will be left. In serious cases, the excessive current will cause life danger. Due to the substantial increase in the length of the distribution network lines, the scale of the distribution network is getting larger and la...

AI Technical Summary

Problems solved by technology

[0003] Up to now, experts and scholars at home and abroad have conducted a lot of research on step voltage, mainly focusing on step voltage simulation and ground resistance test research of power substation grounding grid, as well as risk assessment of distribution network system operation and grid structure risk assessment. etc., there is a lack of a distribution network extreme ground step voltage test and risk assessment technology

However, when the two-phase short circuit of the transmission line is directly grounded, the power frequency overvoltage generated will make the step voltage evaluation method more complicated. In order to accurately evaluate the step voltage, it is urgent to establish an intelligent evaluation platform that can Consider the impact of soil horizontal stratification and direct grounding caused by two-phase disconnection of the line, evaluate the step voltage risk in the surrounding soil area, and conduct a safety risk assessment for the surrounding environment

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