System and method for evaluating two-phase grounding step voltage caused by lightning strike of transmission line under layered soil

Abstract

The invention discloses a system and method for evaluating two-phase grounding step voltage caused by lightning strike of a transmission line under layered soil. The upper end of an experiment box carries a line module; and the lower end of the experiment box carries a step voltage test module. The lower end surface of the experiment box is opened. An impact generator 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 is formed by 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 simulatingtwo-phase broken line ground fault of a power transmission line. The step voltage test module is used for measuring the step voltage under the layered soil. A data analysis module is responsible foroperation and control of other modules and records relevant parameters. The system and method can effectively simulate over-voltage and two-phase broken line ground fault of the line caused by lightning strike on the transmission line under the horizontally stratified soil, and can effective evaluate the step voltage.

Description

technical field [0001] The invention belongs to the field of power system grounding analysis, in particular to a two-phase grounding step voltage evaluation system and method of a lightning strike line under layered soil. Background technique [0002] Lightning strikes on transmission lines are the main cause of power system failures. Two-phase disconnection and grounding faults are common types of faults in power systems, with a high probability of occurrence and serious harm. When the lightning current flows into the earth through the broken power line, a potential rise will be generated near the point where the broken line enters. At this time, when a person stands nearby, a step voltage will be generated, which will cause great harm to the human body. In mild cases, the skin and organs will be burned and scars will be left. In severe cases, excessive current will cause life-threatening. Due to the substantial increase in the length of distribution network lines, the sca...

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Problems solved by technology

[0003] At present, the relevant research on step voltage at home and abroad mainly focuses on the step voltage simulation and ground resistance test of the power plant and substation ground grid, as well as the risk assessment of the distribution network system operation and the risk assessment of the grid structure. Extreme Ground Step Voltage Testing and Distribution Evaluation Techniques

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