China Southern Power Grid Co., Ltd. EHV Transmission Company (CGYKJXM00000015)
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.