Risk assessment experiment platform and method for single-phase ground fault of lightning strike transmission line

Abstract

The invention discloses a risk assessment experiment platform and method for lightning-struck power transmission line single-phase earth fault. The risk assessment experiment platform comprises a power module, a line module, a step voltage test module, an experiment box and a data analysis module. The power module is an impulse voltage source. The experiment box comprises the line module mounted on the upper end and the step voltage test module mounted on the lower end. The impulse voltage source is connected with the line module through a signal wire. The line module is formed by an A phase line, a B phase line and a C phase line. The step voltage test module is connected to a broken line simulator through an earth conductor, and is formed by a simulated ground and a voltage measurement robot, wherein the earth conductor is in close contact with the simulated ground. The risk assessment experiment platform and the method can perform fault inversion according to the situation of the lightning-struck power transmission line single-phase earth fault and can evaluate danger level of the step voltage in the area around the fault point, thereby providing a solid foundation for formulating relevant safety warning and insulation protection measures.

Description

Technical field [0001] The invention belongs to the field of power system grounding, in particular, an experimental platform and method for risk assessment of a single-phase ground fault of a lightning strike transmission line. Background technique [0002] Lightning transmission line faults are the main problem that affects the safe operation of power systems. The transmission and distribution network trip accidents caused by lightning strikes frequently occur. Usually, when the lightning transmission line causes a disconnection and ground fault, the lightning current flows to the ground through the disconnection. This type of high amplitude The high-frequency and high-frequency fault current will pose a great threat to the biosafety of the surrounding area of ​​the disconnection. When the organism is close to the potential area, a potential difference between the two feet will cause a step voltage electric shock accident. Step voltage causes greater harm to the human body, from...

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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, etc. Line-to-ground step voltage testing and risk assessment techniques

When the transmission line is directly struck by lightning, the step voltage evaluation method will become more complicated. In order to accurately evaluate the step voltage under lightning strike, it is urgent to establish an intelligent evaluation platform that can consider the overvoltage caused by lightning strike transmission line. The impact of disconnection, measure the risk of step voltage in the surrounding soil area, and conduct safety assessment

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