摘要
换流站过电压抑制和绝缘配合是±1 000kV级特高压直流输电工程的关键技术之一,对降低设备的绝缘水平和制造难度具有重要的意义。为此,论述了抑制±1 000kV级特高压直流换流站电气设备上的过电压措施及高性能避雷器参数的选取,指出提高避雷器的荷电率和减小避雷器的残压比是降低避雷器保护水平的重要措施,并详细介绍了采用高性能避雷器降低设备绝缘水平的可行性。给出了±1 000kV级特高压直流输电工程设备绝缘配合方法—确定性法,该方法须通过仿真计算可确定合理的避雷器配合电流和配合电流波形,以准确地进行绝缘配合。通过计算,给出了±1 000kV级特高压直流设备冲击绝缘水平的推荐值:±1 000kV、±1 100kV直流极线的操作/雷电冲击绝缘水平分别为1 900kV/2 250kV、2 050kV/2 400kV;±1 000kV、±1 100kV换流变阀侧Y绕组端子/D绕组端子的操作冲击绝缘水平分别为1 950kV/1 500kV、2 050kV/1 600kV。同时,根据线路过电压沿线分布的研究结果,建议线路杆塔绝缘配置应结合线路过电压幅值、分布特性和沿线海拔高度综合分析,并采用分段设计原则以使线路杆塔的造价更加经济合理。
Overvoltage suppression and insulation coordination for converter station equipment are key techniques in ±1 000 kV ultra-high voltage direct current（UHVDC）transmission projects,and they are very important for lowering the insulation level and manufacture difficulty of equipment.Thus,means for equipment overvoltage suppression in ±1 000 kV UHVDC converter stations and for the parameter selection of high-performance metal oxide arrester（MOA） were discussed.It is indicated that increasing charge rate and reducing residual voltage ratio is an important means to lower the protection level of MOA.Moreover,the feasibility of lowering equipment insulation level by adopting high-performance MOA was introduced in detail.The definitiveness method,as the insulation coordination method for equipment in ±1 000 kV and above UHVDC transmission projects,was proposed.Based on simulations,the method can offer reasonable coordination currents and current waveforms which make the insulation coordination accurate.By using the method,recommended values of surge insulation level for ±1 000 kV and above UHVDC equipment can be given： the switching/lightning impulse insulation levels of ±1 000 kV and ±1 100 kV DC pole line are 1 900 kV/2 250 kV and 2 050 kV/2 400 kV,respectively;the witching impulse insulation levels of ±1 000 kV and ±1 100 kV Y winding terminal blocks/D winding terminal blocks on valve side of high voltage converter transformers are 1 950 kV/1 500 kV and 2 050 kV/1 600 kV,respectively.Meanwhile,according to the overvoltage distribution along transmission lines,insulation configurations of towers along a line are advised to be determined by comprehensively analyzing the amplitude and distribution characteristics of the line overvoltage and the altitude along the line,and using principle of subsection design is also suggested for making towers cost more economic and more reasonable.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2013年第3期520-525,共6页
High Voltage Engineering
基金
国家电网公司科技项目(SGKJK[2008]645)~~
