朱冠南,杨晓艺,高宇航,钟昱铭,熊兰,周林.小电流直流电弧的动态模拟及其稳态特性研究[J].电测与仪表,2020,57(1):42-48. ZHU Guannan,YANG Xiaoyi,GAO Yuhang,ZHONG Yuming,XIONG Lan,ZHOU Lin.Study on Dynamic Simulation and Steady-state Characteristics of Low Current DC Arcs[J].Electrical Measurement & Instrumentation,2020,57(1):42-48.
Study on Dynamic Simulation and Steady-state Characteristics of Low Current DC Arcs
Once DC arcs happen as faults, arcs will not extinguish themselves easily for the reason that the DC current does not reach zero value, which is extremely dangerous for the operation of DC power distribution systems. Thus, studying the electrical characteristics as well as temperature distribution of small-current DC arcs is of great necessity. The development of arcs is complex, relating to electric fields, magnetic fields, fluid fields and temperature fields and so on. In this article, the built model of DC arcs based on magneto-hydrodynamics is introduced. Through finite element analysis method, we simulated the developing process of DC arcs to get arc resistances and temperature distributions at different stages during development. Additionally, the numerical fitting model for arcs’ equivalent resistance is established. The regularities and characteristics of arc resistances obtained from the model accords with the experimental results, which the arc resistance is inversely proportional to its current. In the end, we analyzed the factors that are able to affect the characteristics of DC arcs in steady state, proving that the arc current and the electrode distance are key factors. The research results mentioned above provide new ideas for studying small-current DC arcs and theoretical support for DC arc detection as well as equipment protection.