Research On The Arc Extinguishing Time Of Arc Extinguishing Lightning Protection Gap(Aelpg) Based On Chain Arc Model

Arc extinguishing lightning protection gap(AELPG) is a new type of line lightning protection device, not only can through the metal electrode evacuate the flashover arc to make the transmission equipment avoid burning, but also through the inhibition of lines arcing ratio to reduce lightning trip-out rate, and the cost is relatively low.The medium voltage distribution line as a direct connects with user and generally less set lightning line, lightning protection performance is poor, so it is necessary to increase the various aspects of the research of AELPG, improve the relevant parameters system, make this new technology gradually become mature.This paper combined with the characteristics of chain arc model, establish the space physics model of AELPG to analysis the spatial stress of fault arc element, and then according to the stress analysis results, establish the corresponding arc element motion mathematical model to get the fault arc spatial motion and length variation characteristics.Use the arc length of AC arc extinguish criterion as the interrupt vector, the airflow velocity, arc extinguishing angle, the fault arc current value as the arc extinguishing parameters of AELPG, programming calculate the correlation between arc extinguishing parameters and arc extinguishing time by MATLAB. Through large number of test verification, when the parameters of AELPG optimization, the arc extinguishing time can achieve4-5ms.According to the analysis of the arc extinguishing time of AELPG have an competitive advantage than circuit protection action time. By introducing the parameter of arc coefficient K, calculate the lines arcing rate under AELPG is reduced to the original20%～30%.Finally, use arc extinguishing time as correlation parameter, calculate the relationship between arc extinguishing parameters and lightning trip-out rate, for the practical engineering application based on economic, stable, convenient and efficient principle, according to the specific operation target to guide the arc extinguishing parameters of AELPG selection. According to the analysis of actual35kV line statistical results, use the improved regulation method, conclude the line lightning trip-out rate from10.714decreased to3.571when the arc extinguishing parameters optimization and arc extinguishing time shortest.