Research On Insulation Coordination Arc Extinguishing Performance Of Self-energy Compression Arc Extinguishing Cap

At present,the main lightning protection methods for overhead lines are "blocking type" and "draining type".Although a good protection effect has been achieved,problems such as lightning tripping and lightning disconnection have occurred from time to time.In order to reduce the problem of lightning tripping,a Self-energy Arc Compression Extinguishing Gap(SCAEG)is developed based on a "combined" lightning protection method.SCAEG is based on the idea of "impact dredging,power frequency blocking",using its own internal channel effect and the characteristics of elongated arc path at the same time to accelerate the extinguishing of the arc.In this paper,the insulation coordination and arc extinguishing performance of the SCAEG are studied.By comparing the different solving methods of the channel arc model,this paper uses the analytical method and the numerical method to simulate and verify the arc extinguishing effect of the channel.Among them,the analytical method is to establish the arc cylinder model in the channel and combine the Mayr-Cassie arc model.It is verified on the Simulink simulation platform that the channel has an inhibitory effect on arc development.The numerical method is solved by COMSOL Multiphysics finite element software,which verifies that SCAEG can effectively extinguish the arc.This paper studies the arc extinguishing effect of SCAEG through arc extinguishing simulation and experiment.The arc extinguishing simulation is based on a numerical solution.The modeling and simulation of the arc extinguishing process of the unit arc extinguishing structure,SCAEG,and SCAEG with long air gap are realized by COMSOL Multiphysics simulation software.The arc extinguishing process of the unit arc extinguishing structure,SCAEG,and SCAEG in the long air room are tested and verified by the arc extinguishing test.Both simulation and test results show that SCAEG has a good arc extinguishing effect.Among them,the unit arc extinguishing structure can extinguish the power frequency arc of 0.28 k A within 0.6 ms.The SCAEG can extinguish the power frequency arc of 0.55 k A within 0.75 ms.The SCAEG with long air gap can extinguish the power frequency arc of 1.9 k A within 1.8ms.The simulation and experiment of arc extinguishing realizes the research of omnidirectional arc extinguishing performance from local to overall.This article selects column insulators(R5ET105L),pin insulators(P-10T)composite insulators(FXW4)and standard suspension glass insulators(LXY-70)as reference objects.The insulation coordination test research at 10 k V and 35 k V voltage levels of SCAEG,the insulation coordination range of SCAEG is obtained.Compared with the range of a given insulation mix ratio,the specific insulation coordination parameters given in this article according to different insulator models are more practical.Based on the calculation and comparative analysis of the arc formation rate and lightning trip rate before and after the installation of SCAEG,this article shows that the lightning trip rate can theoretically be reduced by more than 90%.The actual application situation at this stage reflects the good operation of the SCAEG,and a relatively effective protection effect has been achieved.