| Parallel protection gap has three major functions, attract lightning discharge, channel stream power frequency arc, uniform power frequency electric field, and it has simple structure, convenient installation and maintenance. As domestic test and study further for parallel protection gap, it’s installation in each voltage grade of power system transmission lines are increasing year by year, so based on the "channel" type lightning protection has been gradually accepted by people. New arcing lightning protection gap add the extinguishing device on the basis of the parallel lightning protection gap, therefore it can extinguish the arc and against lightning-caused breaking of conductors.General parallel protection gap exist two shortcomings, namely to reduce the transmission line insulation strength and increased rate of lightning trip. For its shortcomings, this study makes the following topics:1、Design new arcing lightning protection gap, which does not reduce transmission line insulation level (its primary protection from the air is almost equal the insulation distance of insulator string). Through the production of a variety of structural types (pointed, blunt-shaped, plate-shaped and circular) gap fittings, Through the production of a variety of structural types (pointed, blunt-shaped, plate-shaped and ring) clearance fittings, use the surge voltage equipment for the50%lightning impulse flashover voltage test. Which meet the requirements of the type is selected to assemble new arcing lightning protection gap device. Use the statistics of lightning impulse discharge graph to depict the volt-second characteristic curve of the new arcing lightning protection gap, determine its insulation relationship with the parallel insulator strings. Finally, the depth of new arcing lightning protection gap’s ahead attract lightning discharge theory and use the Ansoft Maxwell finite element analysis software simulation.2、This paper built a test platform, arc extinguishing test and response time test of the arc extinguishing device were done. Which prove that arc extinguishing device can quickly extinguish the stream power frequency arc after lightning flashover. The simulation model of the arc extinguishing device was established with the use of finite element analysis software ANSYS14.0, Used to study the propagation process of the high-speed airflow shock wave, can also be used to study the frequency arc extinction process. The simulation result agree with the experimental result, it is stated that arc extinguishing device reduce the rate of lightning trip and against lightning-caused breaking of conductors.This paper aims to produce a new arcing lightning protection gap, which overcome the shortcomings of reducing transmission line insulation strength and increasing rate of lightning trip on the basis of the original three functions. It is suitable for installation and operation at the higher voltage level transmission line. |
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