接地铜排对变电站二次电缆防护效果研究 |
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引用本文:刘倩,曹雯,苗浩铭,杨昊,纪超.接地铜排对变电站二次电缆防护效果研究[J].电网与清洁能源,2021,37(7):58~64 |
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基金项目:国家自然科学基金项目(51707141) |
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中文摘要:当变电站开关操作遭遇雷击时,接地网会产生地电位差而对二次电缆造成影响,敷设接地铜排能有效阻止电流对二次电缆的损害。基于ATP-EMTP软件建立了一个简化的变电站主接地网仿真模型,对接地铜排与主接地网的连接方式等情况进行研究,分析了接地铜排对二次电缆的防护效果。研究结果表明:增设接地铜排在一定条件下可以降低二次电缆的干扰电压,但接地铜排与主接地网有多个连接点时,在不同位置注入电流,会对电缆芯线与屏蔽层间的电压以及电缆接地点的地电位升产生不同的影响;从电缆2个接地点水平方向的内侧或外侧分别注入电流,接地铜排的影响效果相反,随着接地铜排与主接地网连接点个数的增加,电缆芯线与屏蔽层间的电压和电缆接地点地电位升分别呈增大或减小的趋势。 |
中文关键词:接地网 二次电缆 接地铜排 地电位升 |
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Research on Protective Effect of Ground Copper Bars on Secondary Cables in Substations |
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Abstract:When the substation is switched or struck by lightning, the grounding grid will produce ground potential difference that will affect the secondary cables, and laying ground copper bars can effectively prevent current from damaging the secondary cables. Based on ATP-EMTP software, this paper establishes a simply simulation model of substation primary grounding grid, studies the connection mode of ground copper bars and primary grounding grid, and analyzes the protection effect of ground copper bars on the secondary cables. The results show that added ground copper bars can reduce the interference voltage of secondary cables under certain condition; but when there are multiple connection points between the ground copper bars and the primary grounding grid, injected current at different positions will have different effects on the voltage between the cable core and the shielding layer and the ground potential rise of the cable grounding points. When the current is injected from the inner and outer sides of the two grounding points of the cable in the horizontal direction, the effect of the ground copper bars is opposite, and as the number of connection points between the grounding copper bars and the primary grounding grid increases, the voltage between the cable core wire and the shielding layer and the ground potential rise of the cable grounding point show increasing or decreasing trends respectively. |
keywords:grounding grid secondary cable ground copper bar ground potential rise |
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