特高压直流换流站阀厅金具表面电场计算及结构优化

发布时间：2019-01-27 21:11

【摘要】：随着我国大力推进特高压直流输电工程建设,换流站阀厅作为交流系统和直流系统转换的核心部位,对整个直流输电系统的安全稳定运行有着至关重要的作用,其内部电磁场分布极其复杂,易出现设备尖端的电场畸变和电晕放电。因此,研究阀厅金具表面电场分布对换流站建设和阀厅设计具有重要的工程意义。本文以±800kV特高压换流站阀厅金具为主要对象进行了如下研究:依据高端阀厅电气设备的连接情况,搭建了阀厅3D实体模型,并进行了剖分处理;通过±800kV特高压直流换流系统仿真模型获得了一个工频周期内高端阀厅内部金具的瞬态电位,将其作为加载条件;采用伽辽金边界元法计算了±800kV特高压换流站高端阀厅金具表面电场,该方法只需对金具表面进行合理的剖分处理,避免了三维模型的复杂剖分处理,剖分节点少且计算精度高。计算结果表明,在该设计方案下,阀厅金具表面场强最大位置出现在低压端B相连接管母处,最大值为14.7kV/cm,低于起晕场强限值。仿真结果为阀厅及金具设计提供了参考依据;通过±800kV特高压直流输电系统分层接入方式下的仿真模型,获得了受端低端阀厅典型金具的电位分布;校核计算了传统±800kV低端阀厅金具在分层接入电压激励下的表面电场分布;结合电场仿真结果,对低端阀厅内电场分布恶劣的典型金具进行了结构优化,并提出了一种适用于分层接入方式的±800kV阀厅金具设计方案,从而将阀厅金具表面电场强度控制在一个合理的水平。该计算结果为采用分层接入方式的特高压直流工程设计和建设提供了数据支撑。
[Abstract]:With the development of UHVDC transmission project in China, as the core part of AC system and DC system conversion, the converter station valve hall plays an important role in the safe and stable operation of the whole HVDC transmission system. The distribution of electromagnetic field is very complex and the electric field distortion and corona discharge at the tip of the equipment are easy to occur. Therefore, it is of great engineering significance to study the electric field distribution on the surface of valve hall fittings for converter station construction and valve hall design. The main research object of this paper is as follows: according to the connection of the electrical equipment of the high-end valve hall, the 3D solid model of the valve hall is built and divided; Through the simulation model of 卤800kV UHV DC converter system, the transient potential of the internal hardware of the high-end valve hall in a power frequency cycle is obtained, which is regarded as the loading condition. Galerkin boundary element method is used to calculate the electric field on the surface of the high end valve hall of 卤800kV UHV converter station. This method only needs to carry out reasonable dissection on the surface of the fittings, thus avoiding the complicated dividing treatment of the 3D model, with less nodes and higher calculation accuracy. The calculation results show that the maximum position of the surface field strength of the valve hall fittings appears at the bottom of the B phase connecting pipe at the low pressure end, and the maximum value is 14.7 kV / cm, which is lower than the limit value of the halo field strength. The simulation results provide a reference for the design of valve halls and fittings, and through the simulation model of 卤800kV UHV HVDC transmission system layered access mode, the potential distribution of typical hardware at the lower end of the receiving end is obtained. The surface electric field distribution of traditional 卤800kV low-end valve hall hardware under the excitation of layered access voltage is calculated. Based on the results of electric field simulation, the structure of typical hardware with bad electric field distribution in low-end valve hall is optimized, and a 卤800kV valve hall hardware design scheme suitable for layered access mode is proposed. Thus, the electric field intensity on the surface of valve hall fittings is controlled at a reasonable level. The results provide data support for the design and construction of UHV DC engineering with layered access.
【学位授予单位】：东北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM721.1

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