±535 kV混合式高压直流断路器绝缘结构设计及试验  

Insulation Structure Design and Tests of±535 kV Hybrid HVDC Breaker

作　　者：查鲲鹏 杨岳峰 詹婷 陈宇硕 周剑波 詹雄 ZHA Kunpeng;YANG Yuefeng;ZHAN Ting;CHEN Yushuo;ZHOU Jianbo;ZHAN Xiong(China EPRI Electric Power Engineering Co.,Ltd.,Beijing 102200,China;Beijing DC Transmission&Distribution Engineering Technology Research Center,Beijing 102200,China)

机构地区：[1]中电普瑞电力工程有限公司,北京102200 [2]北京市直流输配电工程技术研究中心,北京102200

出　　处：《南方电网技术》2020年第2期91-97,共7页Southern Power System Technology

基　　金：国家重点研发计划资助项目(2017YFB0902400)。

摘　　要：高压直流断路器是实现直流组网的重要设备。以张北工程±535 kV混合式直流断路器作为研究对象,主要针对其绝缘结构进行分析和设计。运用PSCAD搭建了直流断路器的宽频模型,获得了其内部电压的分布规律;结合系统对断路器的整体绝缘要求,提出了直流断路器关键零部件的耐压水平;在直流断路器整体布局的基础上,结合运行环境、电压波形、电极型式等进行了等电位设计和绝缘配合设计;运用有限元法对直流断路器三维全场域模型进行了典型工况下的电场校核;在此基础上,对直流断路器的绝缘结构进行了试验验证。通过本文研究,提出了适用于直流断路器绝缘结构的模块化、分区域、分层级和单点就近固定电位的设计方法;直流断路器金具表面最大电场强度在雷电冲击电压下为27.7 kV/cm,在分断过程中为19 kV/cm;直流断路器在型式试验中未发生闪络或击穿,满足了工程应用要求。研究结果可为高压设备的绝缘结构设计提供参考。HVDC breaker is an important device for realizing DC networking.Taking±535 kV hybrid DC breaker of Zhangbei HVDC grid project as the research object,its insulation structure is mainly analyzed and designed in this paper.The trend of voltage distribution for the DC breaker is calculated with wide-band circuit model by PSCAD.Combined with the overall insulation requirements of the DC breaker,the withstand voltage levels for the key components are proposed.Based on the overall layout of the DC breaker,the equipotential design and insulation coordination are carried out,considering the operating environment,voltage waveforms and electrode types.Under typical operating conditions,the electric field distribution of the whole three-dimension DC breaker is calculated and evaluated by the finite element simulation software.The insulation tests of the DC breaker are carried out.Through the research of this paper,one suitable design method for the insulation structure of DC breaker is proposed,which is modular,sub-regional,layered and single-point nearby potential fixed.The maximum electric field strength on the surface of DC breaker fittings is 27.7 kV/cm under the lightning impulse withstand voltage,and 19 kV/cm during the fault current breaking process.No flashover or breakdown occurs during the type tests,satisfying the requirements of engineering applications.The research results can provide reference for the insulation structure design of high-voltage equipment.

关 键 词：高压 混合式直流断路器 耐压水平 绝缘配合 电场仿真 试验 

分 类 号：TM721[电气工程—电力系统及自动化]