Study On Calculation Model Of The Critical Current For The Prevention Of Conductor Icing And Its Impacting Factors

Conductor icing seriously affected the safe operation of the power system, and oneof the hot spots of domestic and foreign research is to explore scientific and effectivemethods for conductor anti-icing. The use of the Joule Heat generated by energizedconductor let the surface temperature of conductor become higher than the temperatureof ice formation, and then conductor icing can be prevented, which is a simple andeffective method for the prevention of conductor icing. So it has important academicsignificance and engineering application prospects to study on the critical current for theprevention of conductor icing.In this paper, the simulation model of gas-liquid two-phase flow across conductoris established by using Euler-Lagrangian method, the droplets collision coefficient ofdifferent conductors is calculated, the calculation model of critical current is establishedwith the skin effect and the effect of geometric shapes, water film covering conductorsand atmospheric parameters on heat transfer process comprehensively considered, andthe model is validated by the critical current test of three kinds of conductors (LGJ-95,LGJ-240, LGJ-300) carried out under icing environment in artificial climate chamber.By analyzing the test results, simulation results and the calculation model of criticalcurrent, the following conclusions are obtained in this paper.â‘ By analyzing droplets collision characteristics, the formula for calculatingdroplets collision coefficient is proposed.â‘¡By analyzing the influence on heat transfer process of conductor surface by thewater film covering conductor, the concept of the surface coefficient is proposed, andthe value of the surface coefficient is obtained.â‘¢According to the experimental results and theoretical analysis, the calculationmodel of critical current is established which is validated by the critical current test, andthis paper indicate that transmission line icing can be prevented and ice storm can beavoidable when the load current of transmission line is larger than the critical current forthe prevention of conductor icing.â‘£The critical current is related to conductor diameter, geometric shapes, airtemperature, wind speed, liquid water content and median volume diameter. The criticalcurrent significantly increases with the decrease of temperature, increases with theincrease of wind velocity, conductor diameter, liquid water content, and median volume diameter.