特高压环氧浸纸−SF_(6)气体复合绝缘穿墙套管界面电荷积累过程和直流电场分布特性仿真  

Simulation of Interface Charge Accumulation Progress and DC Electric Field Distribution Characteristics of the UHV Epoxy Impregnated Paper-SF_(6)Gas Composite Insulation Wall Bushing

作　　者：王青于 靳守锋 袁书文 刘鹏[1] 彭宗仁[1] WANG Qingyu;JIN Shoufeng;YUAN Shuwen;LIU Peng;PENG Zongren(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,西安710049

出　　处：《高电压技术》2022年第10期4102-4112,共11页High Voltage Engineering

基　　金：国家电网公司科技项目(SGLNDK00KJJS1900250)。

摘　　要：特高压直流穿墙套管作为换流站中连接阀厅和直流场的唯一通道,是承载系统全电压、全电流的核心设备,掌握穿墙套管在直流电压下的电荷积累特性和暂态电场变化规律对保障其运行可靠性具有重要意义。为此以±1100 kV直流环氧浸纸–SF_(6)气体复合绝缘穿墙套管为研究对象,建立基于介质内部和分界面上电荷驰豫过程的复合绝缘系统电场模型,提出一种气体饱和电流密度的简化计算方法,以解决求解复杂仿真模型时对流扩散方程收敛较为困难的问题,利用该模型研究环氧浸纸–SF_(6)气体复合绝缘穿墙套管直流电场过渡过程和界面电荷积累现象,并结合三维电磁–热–流场数值计算,获得环氧浸纸–SF_(6)气体复合绝缘穿墙套管的三维温度场分布,分析环氧浸纸–SF_(6)气体复合绝缘穿墙套管在实际运行工况下的电–热耦合场分布规律。相关结论可为环氧浸纸–SF_(6)气体复合绝缘穿墙套管的结构优化设计、寿命评估和故障分析提供理论依据。As the only channel connecting valve hall and DC field in a converter station,UHV DC wall bushing is the core device that carries the full voltage and current of the system.To guarantee the reliability of its operation,it is of great significance to master the charge accumulation characteristics and transient electric field distribution of the wall bushing under DC voltage.Consequently,taking the±1100 kV epoxy impregnated paper-SF_(6) gas composite insulation wall bushing as the research object,we established an electric field model of the composite insulation system based on the charge relaxation process inside the medium and the interface;meanwhile,we proposed a simplified calculation method of the gas saturation current density to solve the complex simulation model when the convection diffusion equation is difficult to converge.Moreover,we researched the DC electric field transition process and the interface charge accumulation phenomenon of the epoxy impregnated paper-SF_(6) gas composite insulation wall bushing after applying the model.Combined with the 3D electromagnetic-thermal-flow coupling field numerical calculation method,the 3D temperature field distribution of the epoxy impregnated paper-SF_(6) gas composite insulation wall bushing was obtained.The electric-thermal coupling field distribution law of the epoxy impregnated paper-SF_(6) gas composite insulation wall bushing under actual operating condition was analyzed.The relevant conclusions can provide theoretical basis for the structural optimization design,life evaluation and failure analysis of the epoxy impregnated paper-SF_(6) gas composite insulation wall bushing.

关 键 词：穿墙套管 暂态电场 界面电荷 温度场 电–热耦合场 

分 类 号：TM216.52[一般工业技术—材料科学与工程] TM721.1[电气工程—电工理论与新技术]