Research On Electric Field Distribution Of High Voltage DC Insulator Surface With The Space Charge

High-voltage direct current transmission technology has many advantages over actransmission technology. Since the1950s, High-voltage direct current transmissiontechnology has had fast development. High-voltage direct current transmission technologyof our country had been into the early stage in the1980s. Due to the characteristics ofresource distribution in China, transporting western resources to the economicallydeveloped eastern requires a lot of manpower and material resources. Transporting energyby electricity, especially in high voltage direct current transmission will bring greateconomic benefits.First of all, according to the control equation of the ion flow field of dc transmissionline, this paper puts forward the finite element iteration calculation method. Ion flow fieldcontrol equation is converted to two equations, to set up the charge density of the initialvalue, and then to solve the potential value of the two equations. Space charge density ismodified according to the potential difference of two equation and to calculated again,until the potential difference meets the permissible error of two equations. Two-dimensional program is compiled to calculate the ion flow field control equation of coaxialcylinder electrode and the calculation results are compared with the analytical solution toverify the validity of the method.Secondly, on the basis of the ion flow field of HVDC transmission line, dc insulatorion flow control equation and finite element iteration method is proposed. Introducing theinsulator, the specific process of finite element iterative format is detailed introduced, andthen three different models of dc insulator are calculated.Finally, dc insulator surface potential distribution considering the space charge andinsulator surface potential distribution of static electric field is compared. Considering thespace charge, dc insulator surface potential is significantly higher than the insulator surfacepotential in the electrostatic field. Electric field intensity at the top of the dc insulator is less than the electric field intensity of the electrostatic field. Electric field intensity of thebottom of dc insulator is greater than the electrostatic field of the electric field intensity. So,in the design of dc insulator, the influence of space charge of dc transmission line shouldbe considered.