界面空间电荷对高压直流电缆终端电场分布的影响

为了分析高压直流电缆终端主绝缘与加强绝缘界面空间电荷分布对直流电缆终端最大场强的影响,应用电声脉冲法测试了交联聚乙烯与非线性硅橡胶双层介质中的空间电荷分布。根据界面空间电荷分布特性,确定空间电荷包参数,并应用多物理场耦合软件COMSOL Multiphysics仿真分析了考虑界面空间电荷时的高压直流电缆终端电场分布。结果发现:高压直流电缆终端的电场分布受交联聚乙烯和非线性硅橡胶界面空间电荷及其在绝缘层中分布的影响,界面空间电荷分布的中心峰值小于2 C/m^3时,空间电荷对电缆终端内电场分布的影响不明显;空间电荷分布峰值大于2 C/m^3时,绝缘层中的空间电荷分布越宽,终端内最大场强越大。

Effect of Interfacial Space Charge on Electric Field Distribution of HVDC Cable Terminal

In order to analyze the influence of space charge distribution in the main insulation and reinforced insulation on the maximum field strength in the high voltage DC cable terminal,the space charge distribution in the double-layer dielectric and its interface of cross-linked polyethylene and non-linear silicone rubber is measured by electro-acoustic pulse method.According to the interfacial space charge distribution characteristics,and by means of the space charge packet parameters,the maximum field strength in the high voltage DC cable terminal is analyzed by COMSOL Multiphysics simulation software.It is found that the electric field distribution in the high-voltage DC cable terminal is affected by the interfacial space charge and the space charge distribution in cross-linked polyethylene and nonlinear silicone rubber.When the peak value of the interface space charge is less than 2 C/m^3,the effect of space charge on the electric field distribution in the cable termination is not obvious.When the peak value is greater than 2 C/m^3,the wider the space charge distribution in the insulation layer,the larger the maximum field strength in the cable terminal.