20kV架空绝缘电缆防雷措施的研究

20 kV电压等级作为一种新型的配电电压等级,目前已在世界范围内被公认为可以取代10 kV电压等级。工程应用表明,20 kV线路多采用架空绝缘电缆,但架空绝缘电缆的雷击事故率却明显高于传统的架空裸导线。针对上述状况,全面分析了架空绝缘电缆雷击事故的特点,计算了20 kV线路多种情况下的感应雷过电压幅值。计算结果表明,感应雷过电压幅值可大于450 kV,超过现有20 kV线路的绝缘水平。基于10 kV线路以往的防雷经验和措施,分析并提出综合运用氧化锌避雷器、过电压保护器、屏蔽分流线等防雷措施来保护20 kV架空绝缘电缆线路。该研究为20 kV配电网安全供电提供了参考。

Research on Lightning Protection of 20 kV Overhead Insulated Lines

As a new distribution voltage level,20 kV voltage level has been recognized that can replace the 10 kV voltage level in the world.Engineering applications showed that 20 kV transmission lines usually use overhead insulated cables,but its lightning stroke rate significantly higher than traditional bare overhead conductors.This paper makes a comprehensive analysis on lightning accident of the overhead insulated cables,calculates its amplitudes of the lightning overvoltage on the 20 kV overhead insulated distribution lines.The results show that the lightning over-voltage amplitude can be greater than 450 kV which over the existing insulation level of 20 kV lines.Drawing on the past lightning protection experiences and measures of the 10 kV transmission lines,this paper propose that comprehensively use zinc oxide arrester,overvoltage protection,shielding shunting line and other lightning protection measures to protect the 20 kV overhead insulated cables.This study provides a reference to the safe power supply of 20 kV distribution network.