柔性直流换流阀串联支撑绝缘子电压分配均衡方法  

Improving the Voltage Distribution of the Insulator String of Flexible HVDC Converter Valve

作　　者：李静怡 沈弘 刘珂鑫 齐磊 崔翔 Li Jingyi;Shen Hong;Liu Kexin;Qi Lei;Cui Xiang(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京102206

出　　处：《电工技术学报》2018年第21期5128-5135,共8页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划资助项目(2016YFB0900904)

摘　　要：随着电压等级的提升,柔性直流换流阀常采用绝缘子串联的多层支撑结构设计,从而保证足够的对地绝缘间隔。然而在模型测试中出现了换流阀各层绝缘子电压分配不均的问题,使得绝缘子选型困难,增加了换流阀的设计成本与难度。针对某±800kV柔性直流换流阀塔,分析了交直流绝缘型式试验下造成串联支撑绝缘子电压分配不均的原因,建立电路计算模型,提取模型中的电容和电阻参数,通过与电准静态场计算结果对比,验证了电路计算模型的正确性。在此基础上,提出串联支撑绝缘子连接法兰与水路等电位联结的电压均衡方法,计算分析水管长度、等电位联结的水管根数、支撑绝缘子的数量和高度及等电位联结位置对串联支撑绝缘子电压分配的影响规律,并结合工程设计要求,确定串联支撑绝缘子的电压分配均衡方案。电路计算模型与水路钳制均衡方法相结合,避免了反复建模与复杂的电场数值计算,能够在满足设计需求的同时,大大节约设计成本与时间。With the upgrade of the voltage level,flexible DC converter valves often adopt multilayer support structure design of the insulators in series,so as to ensure enough insulation interval to the ground.However,in model tests,there was a problem of uneven voltage distribution across the insulator of the commutation valve,making it difficult to select the type of insulator.This will increase the design cost and difficulty of the converter valve.Aiming at±800 kV DC converter valve tower,this article analysis the uneven voltage distribution in series supporting insulators under the AC-DC insulation type test,established a circuit calculation model and extracted the capacitance and resistance parameters in the model.By comparing with the calculation results of the quasi-static electric field,the correctness of the circuit calculation model is verified.Based on the above,this article put forward a method to make voltage distribution evenly by setting the potential clamp point between the water pipe and the series insulator.In addition,the influence of water pipe length,the number of water pipes connected by equipotential bonding,the number and height of insulator strings and the position of equipotential bonding on the voltage distribution of series supporting insulators were calculated and analyzed.Then combining with engineering design requirements to confirm the voltage distribution scheme on series supporting insulators.The two methods can not only meet the design demand,but also significant save costs and time in designing.

关 键 词：柔性直流换流阀 串联支撑绝缘子 电位分配 优化方法 

分 类 号：TM854[电气工程—高电压与绝缘技术]