Study Of On-Line Anti-Icing Method On Electrified Railway Catenary

The total mileage of electrified railway has rapidly grown in the recent years, and with the development of high-speed railway, the railway transport capacity has increased substantially. In China, Spring Festival rush is always the peak railway travel season. In order to ensure the railway safe operation in winter, online anti-icing technique should be put into practical applications urgently. It can solve the problem of catenary icing in time, making railway operate normally; meanwhile, it eliminates the risk of manual deicing. As the power electronic technology has gradually become mature, the large capacity of reactive power compensation device come out one after another. It provides conditions of engineering realization for catenary online anti-icing. At the same time, the related theoretical study needs to be developed and improved.This paper researched the effect of the meteorological conditions such as temperature, wind speed and air humidity on catenary icing, setting and judging the conditions of anti-icing operation modes. By analyzing the heat exchange of ice coating on contact line, a simplified heat balance equation of contact line was built with the anti-icing state. Select the wire parameter to calculate the current distribution coefficients of catenary, calculating the critical anti-icing current for catenary under the assumed meteorological parameters and verifying its feasibility.An on-line anti-icing technology used static var generator (SVG) for catenary along the railway was studied. The electric relation of the anti-icing current and the terminal voltage were analyzed in direct power supply system in various operation modes. So does the relation between load location and catenary voltage. A decision method of anti-icing current which makes catenary terminal voltage as control objective was proposed. The relation between the number of locomotive in a power supply section and train departure interval as well as train speed was calculated. By assuming a train operation diagram and calculating measured data, anti-icing current decision-making mode was validated that it can control the voltage of traction power net in the allowed range.The Matlab/Simulink simulation modeling was completed to study the anti-icing current and the terminal voltage of the catenary. An appropriate current control strategy was selected for SVG device, so that SVG device could quickly response to the instruction anti-icing current. SVG can absorb the specified inductive or capacitive anti-icing current, and it also can change either inductive or capacitive mode following the change of the terminal voltage. The result of simulation showed that both the terminal voltage and load voltage are in the permitted range when the anit-icing device was working, which proved the anti-icing method and current decision-making mode was feasible. Research the application of key devices of the combined co-phase traction power supply system in the field of anti-icing, using its characteristics of the flexibility to control reactivity power, simulating and realizing the function of anti-icing by integrated power flow controller (IPFC) devices.