Study On Method Of Deicing By Live-line Segmented DC And Model Of Dynamic Ice-melting Ontransmission Lines

Operation experience shows that serious icing of transmission lines have endangered the safe and reliable operation of transmission lines.At present,the short-circuit thawing method is often used to deicing the transmission lines.This method can only be carried out under the condition of transmission line shutdown,which reduces the power supply reliability of the power grid,causes huge losses to the national economy,and brings great inconvenience to people production and life.Therefore,it has important engineering application value to propose a non-power-off,flexible and convenient ice-melting method for transmission lines with split wires.In view of the disadvantages of the existing short circuit direct current deicing methods such as power outage and low deicing efficiency.In this paper,a new method of direct current ice-melting for transmission lines with split wires is proposed.In this paper,the basic principle of DC ice-melting is analyzed,and the structure of ice-melting circuit and the design of ice-melting power supply are studied.ATP-EMTP software is used to simulated and analyzed the flow of ice-melting current in the melting section and the influence of the DC ice-melting power supply on the current and voltage outside the ice-melting section.Under the experimental conditions,the physical platform of the DC ice-melting method for transmission lines is set up.Secondly,on the basis of this ice-melting method,by analyzing the heat conduction process of split conductor and ice surface,the governing equations of electromagnetic field and heat transfer of phase transition are deduced,and the dynamic ice-melting model of conductor is established.Finite element simulation software is used to analyze the phase transition process of ice in the process of ice-melting,the temperature distribution and the time of ice-melting in the process of ice-melting.The deicing time of the existing short circuit DC deicing method is compared with that of living segmented DC ice-melting method.Finally,the influence factors of transmission lines icing are analyzed,and the selection of critical ice-melting circuit under different ambient temperature,icing thickness and wind speed is simulated by finite element software.And the influence of different working conditions on the melting time.The results show that the bundled conductors have no effect on the external voltage and current waveforms in the ice-melting section when the DC ice-melting method used,and the transmission lines are in normal operation state.Moreover,the deicing time of the live segmented DC ice-melting method is 2.3 times shorter than that of the existing short circuit deicing method.It provides an effective solution for the live ice-melting of transmission lines with split wires in the future.