Research On Arc Stabilization Method Based On Longitudinal Air Flow

The pantograph-catenary current is the only way for high-speed trains to obtain electrical energy.In the process of sliding electrical contact,vibration is unavoidable and the state between electrodes changes from contact to separation,thus generating electric arc.The strong energy impact produced by arc discharge leads to serious erosion of electrode materials.With the development of high-speed trains to higher speeds,the electrical and mechanical coupling between the pantograph and the catenary makes the damage aggravated.Non-contact energy transfer can decouple mechanical and electrical damage and separate the sliding contact interface,thereby eliminating the influence of mechanical friction and wear and mechanical impact on the power transmission process,and providing posssibility of the development of higher-speed trains in the future.Therefore,researches are carried out gradually.Arc has excellent electrical conductivity and thermal conductivity.Relevant researchers believe that it is feasible to use arc as an intermediate medium for high-power energy transmission,and arc energy transfer technology has broad prospects.In the actual application process,the arc is in an open atmospheric environment,cross wind cannot be avoided,and the arc stability decreases.The arc stability determines the application quality of the arc,and the stability of the arc is one of the key difficulties in the arc energy transfer technology.At present,there are still deficiencies in the research on arc stability,such as the lack of related research on arc characteristics in cross-wind environment and the control of arc stability in cross-wind environment.Therefore,this paper builds a test platform and a simulation model,systematically studies the arc stability and its influencing factors under the action of cross wind,and further introduces longitudinal airflow to control the arc stability under the action of cross wind.The research results can enrich the air arc theory in special environments,and lay the foundation for the flexible arc energy transfer technology for higherspeed high-speed railways in the future.The research on arc characteristics and mechanism under the action of cross wind was carried out.Three electrode materials were analyzed from the perspectives of arc maintenance and electrode erosion,and explained from the perspective of electron emission.The effect of cross wind was explored from the perspective of arc voltage characteristics.The influence mechanism of the current and gap on the arc stability was studied and the change rule of the arc motion mode under different currents and gaps was explored.It was found that under different parameter conditions,along with the change of the arc stability,the arc motion mode changed as follows: "arc root random jumping type-arc root regular jumping type-bell jar type".The mapping relationship between the arc motion mode and the arc stability was analyzed,and the reasons for the transformation of the macroscopic motion mode were clarified from the analysis of the arc force and the arc electron density.The multiple regression method was used to study the variation law of the minimum holding current under different parameter conditions is explored.Considering the effect of cross wind,an arc magnetohydrodynamic model is established,and it is proposed to use the longitudinal airflow to control the arc stability under the effect of the cross wind.The effect of arc stability characteristic quantities such as range and voltage standard deviation was studied,and the influence of electrode gap size on arc stability was explored.It was found that longitudinal airflow can delay the arc root movement and arc column development process,reduce arc voltage fluctuations,and improve arc stability.At the same time,there is a "U-shaped" relationship between the longitudinal airflow velocity and the standard deviation of the arc voltage.The influence mechanism of the airflow velocity distribution and the arc radial current density distribution is analyzed from the macro and micro perspectives.