采用纳米改性纸板的换流变压器出线装置电场分布

针对换流变压器出线装置在直流及极性反转电压作用下电场分布不均的问题,探究了非线性纳米Si C对绝缘纸板进行改性的方法,制备了纳米改性绝缘纸板试样,并测量了改性纸板的介电特性;结合换流变压器出线装置的实际结构建立了电场分布的仿真模型,分析了纸板改性对出线装置电场分布的均化作用。试验结果表明:纳米改性绝缘纸板的相对介电常数随纳米Si C掺杂浓度的增加而增加,但增加的幅度不大,随电场强度的增加呈略微上升的趋势;其电导率随着纳米掺杂浓度的增加而增加,当掺杂浓度达到一定值时,电导率随场强增加表现出明显的非线性特征。仿真结果表明:在直流和极性反转电压下,纸板改性可降低绝缘纸板中的场强,提高变压器油中的场强,使油纸绝缘结构中的电场分布更趋于均匀。

Electric field distribution of converter transformer barrier system using nano modified pressboard

In order to solve the problem of electric field distribution concentration in converter transformer barrier system under DC and polarity reversal voltages, the method of modification to pressboard with non-linear nano SiC was explored, and the nano SiC modified pressboard samples were manufactured, the die-lectric properties of modified pressboard was measured. The electric field distribution simulation model of converter transformer barrier system was built considering its practical structure, and the homogenization effect of pressboard modification on barrier system electric field distribution was analyzed. The experiment results show that the permittivity of modified pressboard increases with the increase of nano SiC doping ra-tio but not obviously and there is a slight rising trend with the electric field strength increasing. The con-ductivity of modified pressboard increases with the increase of nano SiC doping ratio, and it shows obvious nonlinearity between conductivity and electric field strength when the doping ratio exceeds a certain val-ue. The simulation results show that the electric field strength in pressboard can be reduced by using nano modified pressboard, and electric field strength in oil will be heightened, which can make the elec-tric field distribution in oil/pressboard insulation structure more homogeneous under DC and polarity re-versal voltages.