舟山柔性直流输电工程的直流电缆操作过电压计算与分析  

Switching Overvoltage Calculation and Analysis of DC Cables for Zhoushan Flexible DC Transmission Project

作　　者：李炼炼[1,2] 蔡炜[1,2] 杨黎明[1] 李牧[1,2] 郑新龙[3] 范鹏[1,2] 

机构地区：[1]南瑞集团公司(国网电力科学研究院),南京211106 [2]国网电力科学研究院武汉南瑞有限责任公司,武汉430074 [3]国网浙江省电力公司舟山供电公司,舟山316004

出　　处：《高电压技术》2017年第11期3645-3652,共8页High Voltage Engineering

基　　金：国家电网公司科技项目(2014320001510110)~~

摘　　要：高压电力电缆在柔性直流输电工程中扮演中输送稳定电能的重要角色,其过电压故障会对电网安全运行造成严重的影响,而国内关于高压电缆操作过电压机理以及计算的研究较少。为此,依托舟山柔性直流输电工程,在PSCAD/EMTDC平台上,分析了同轴高压直流电缆的等效阻抗和导纳参数,并分别计算了不同故障条件下的直流电缆操作过电压。基于统计分析方法,采用线路分段技术研究了直流海底电缆的操作过电压沿线分布规律。研究结果表明:直流电缆沿线接地故障过电压值呈伞形分布,中部最大,两侧递减;导体-铅套操作过电压最大值为400.2 kV,发生在直流电缆沿线接地故障的条件下;铅套-铠装和铠装-大地操作过电压最大值分别为7.27 kV和0.45 kV,发生在交流相地和相间故障的条件下;导体-铅套、铅套-铠装和铠装-大地操作冲击绝缘水平分别为460.23 kV、8.36 kV和0.52 kV。该研究结果可以为高压电力电缆线路的绝缘配合提供重要的依据。High-voltage power cables play an important role in voltage stabilization in flexible DC transmission project, overvoltage fault can have serious impact on the safe operation of power grid, and there are few domestic studies on the mechanism and calculation of switching overvoltage. We analyzed the equivalent impedance and admittance matrix of coaxial HVDC cables and calculated the switching overvoltage of DC cable under different fault conditions. The study on the platform of PSCAD/EMTDC was based on Zhnushan flexible DC power transmission project. Moreover, we analyzed the switching overvoltage distribution of the DC submarine cable by using the line segment technology. The results prove that it is an umbrella distribution that the center is the largest and the two sides are decreasing; the maximum overvoltage is 400.2 kV between conductor and lead sheath when the ground fault condition of de cable occurs, it is 7.27 kV between armor and lead sheath, 0.45 kV between ground and armor when phase-to-ground and phase-to-phase faults occur. The maximum overvoltage is assured by statistical analysis; the insulation level of the cables is 460.23 kV between conductor and lead sheath, 8.36 kV between lead sheath and armor, 0.52 kV between armor and ground. The results can provide the references for insulation coordination of high-voltage power cables.

关 键 词：高压电力电缆 柔性直流 阻抗矩阵 导纳矩阵 操作过电压 绝缘配合 

分 类 号：TM721.1[电气工程—电力系统及自动化]