基于有限元法的换流阀水路系统电场分析

在高压直流输电工程中,换流站阀塔内冷水系统会出现漏水故障,严重影响特高压直流输电的稳定性。针对该类漏水故障问题,从阀塔内冷水回路场强因素考虑,采用有限元仿真和实验的方法,搭建了仿真所需的阀塔内冷水回路三维模型和水路局部模型,根据阀塔运行条件对内冷水系统作了电场仿真分析,同时设计了验证实验进行探究。仿真结果表明,内冷水系统回路的冷却水管表面场强部分大于空气击穿场强,等电位线会影响冷却水管周围电场。实验证实在一定条件下等电位线与冷却水管间会有明显放电现象,研究内容为阀塔漏水事故原因分析提供了参考依据。

Electric field of valve cooling system in thyristor valve based on finite element method

In the HVDC transmission project, the problem of water leakage in the valve cooling system of the converter station will seriously affect the stability of the HVDC transmission. To study the problems like above, it will consider the factor of electric field strength around the cooling system in valve tower, and the method of finite element analysis is used to construct the three-dimensional model of the cooling system in the valve tower and a detailed model of S-type pipe. The electric field simulation is performed according to the operating conditions of the valve tower. In the end, an experiment is designed to verify the FEA model. The results of simulation show that the electric field strength of some parts of cooling water pipe is greater than the air breakdown field strength and the grading wire will reflect on the electric field around cooling water pipes. The experiment proves that there will be obvious discharge between the electric grading wire and the cooling water pipe under certain conditions. The research provides a reference for the analysis of the cause of water leakage accidents in valve towers.