Research On Multi-break Point Active Arc-extinguish Gap Lightning Protection Of 35kV Distribution Line

With the progress of science and technology and the continuous development of economy in our country,the power demand is growing,the scale of power grid is also increasing,and the reliability of power grid becomes more and more important..After decades of research in China,through the "blocking" lightning protection means,it can effectively reduce the lightning trip rate,but the cost is high and the maintenance is complex.Therefore,the "Dredging" lightning protection means as a supplement to the "blocking" lightning protection means are gradually developed and applied.Parallel clearance,as a mature "dredge" lightning protection method,has been widely used,but it is to sacrifice the trip rate in exchange for the permanent failure of the line.Frequent action of the circuit breaker will increase the burden of the circuit breaker and increase the hidden danger for the safe operation of the power system.In view of the above problems,this paper studies a new type of arc extinguishing and lightning protection device: multi breakpoint arc extinguishing and lightning protection gap: multi-break point arc-extinguishing lightning protection gap,which is a kind of parallel gap composed of "self energy" arc-extinguishing lightning protection device.The multi-break point arc-extinguishing lightning protection device can extinguish the arc in the process of impact arc generation,cut off the energy input path of power frequency arc,improve the effectiveness of arc extinguishing,and ensure that the line does not have permanent fault and does not Tripping greatly improves the reliability of line operation.The operation experience shows that the multi-break point arc-extinguishing lightning protection gap can effectively reduce the lightning trip rate of 35 k V Transmission line.In this paper,the arc extinguishing process of the multi-break point ar-extinguishing lightning protection device is simulated by Fluent software,and the multi-break point arc-extinguishing lightning protection device is extinguished by observing the temperature in the middle of the arc-extinguishing pipeline,the end of the arc-extinguishing pipeline,the arc bend,the speed and pressure of the expansion air flow and the total internal energy in the arc-extinguishing pipeline analyze the arc-extinguishing time of arc lightning protection device,and verify the effectiveness of the device.In practical application,at present,there is no research on the insulation coordination of multi-break arc-extinguishing gap and insulator.In this paper,the lightning impulse characteristics and volt second characteristics of 35 k V glass,composite insulator string and multi-break arc-extinguishing gap with different gap distance are studied.The experimental results show that: multi-break arc-extinguishing andlightning protection gap can effectively protect the insulator after lightning stroke;under the same effective gap distance,the insulation level of multi-break arc-extinguishing lightning protection gap is higher than the parallel gap;through the experiment,the effective protection distance of multi-break arc-extinguishing lightning protection gap is given.This conclusion can provide reference for the installation of multi-break arc-extinguishing lightning protection gap.