应力锥体增强绝缘非线性属性对HVDC电缆终端电场分布的影响

Effect of Nonlinear Properties of Stress Cone Reinforced Insulation on Electric Field Distribution of HVDC Cable Terminal

高压直流电缆及附件稳态电场分布主要取决于绝缘材料的电导率，而电导率又与场强、温度紧密相关，这使得直流电缆附件电场分布相比高压交流电缆附件更复杂。为此，在固定电缆终端XLPE绝缘、硅油电导率和温度梯度的条件下，本文采用多物理场耦合软件仿真研究了应力锥体增强绝缘非线性属性对高压直流电缆户外复合型终端稳态电场分布的影响规律。仿真研究结果表明：复合型户外高压直流电缆终端，工厂绝缘和增强绝缘界面切向电场在应力锥体根部和顶部可能出现极大值；而在半导电应力锥内表面电场也可能在根部和顶部出现极大值；通过调控增强绝缘材料的非线性属性可实现复合型电缆终端电场分布的综合调控。

The steady-state electric field distribution in HVDC cables and accessories mainly depends on the conductivity of insulating materials, and the conductivity is closely related with the electric field and temperature. So the electric field distribution of HVDC cable accessories is more complex than the electric field distribution of HVAC cable accessories. In this paper, the influence of nonlinear properties of stress cone reinforced insulation on the steady-state electric field distribution of outdoor compound terminal of HVDC cable is studied using COMSOL Multiphysics software, and under the conditions in which the XLPE insulation conductivity, silicone oil conductivity and the temperature gradient in the cable terminal are fixed. The simulation results show that： the tangential electric field at the interface between the factory insulation and the reinforced insulation in the compound outdoor HVDC cable terminal will show the maximum field at the root and top of the stress cone, and the electric field of the inner surface of the semicon stress cone may also appear the maximum field at the root and the top. The comprehensive regulation of electric field distribution of compound HVDC cable terminal can be realized by adjusting the nonlinear properties of the stress cone reinforced insulation.