Numerical Analysis Of Electrical Properties In 35kV Tubular Insulated Bus-Bar

With the development of electric power in China,the market of insulated tubular bus-bar with good electrical performance is also expanding.Solid insulated tubular bus-bar has many advantages of large carrying capacity,strong insulation performance and high mechanical strength.Because of its mature technology and excellent electric properties,it is widely used in the low-tension side of substation in our country.However,there are still many problems to be solved in the using process,which restrict its development.Taking 35 kV insulated tubular bus-bar as research object;the first part studies the electric-field distribution and voltage distribution of tubular bus-bar.Its potential electric breakdown position can be obtained by calculating the maximum electrical intensity,and then puts forward several kinds of structures as optimized structures to prevent the breakdown.The second part studies the temperature distribution of tubular bus-bar by the finite element analysis,and calculated its carrying capacity.The temperature of tubular bus-bar would directly affect the carrying capacity,so keeping temperature rise within allowable limits can improve the using-efficiency.If the structural support and steel structure near the tubular bus-bar is unreasonable,it will make the steel structure parts overheating or destroying.So taking the common steel structure as examples,the third part analyzes the problem of induction heating on steel structure around the tubular bus-bar by using thermoelectric coupling method,controlling the heating temperature within the scope of the permit.In the fourth part,the temperature distribution on the bus-bar body joint is studied,and it is analyzed from three aspects: contact resistance,ac loss and eddy current loss.The temperature distribution on the bus-bar body joint is calculated based on the multi-field coupling principle,and then author analyzes the influence factors of the temperature on the body joint.This paper analyzes and calculates the electrical characteristics of 35 kV insulated tubular bus-bar from various aspects such as electricity,magnetism and heat.According to the electric-field intensity and voltage distribution,it would be concluded that there is no such phenomenon as insulated breakdown.According to the temperature distribution of tubular bus-bar and its body joint,the temperature rise is within the allowable range.According to the temperature on the steel structure around bus-bar,the heating doesn't affect the surroundings.In order to measure whether it meets the standards of the national standards of power grid,and safeguard the safe and stable operation of our country's power grid.