风电场圆环接地网的冲击特性研究
发布时间：2019-05-07 23:36
【摘要】：接地系统是保证风电场安全运行的重要组成部分之一,接地网雷电冲击电流入地点处的电位较高问题一直是威胁设备及人身安全的主要问题之一,为了有效降低接地网雷电冲击电流注入点处的电压,并对接地网的冲击电位分布进行改善,本文对风电场圆环接地网的冲击特性进行研究分析。本文首先建立了圆环接地网的几何模型,然后在考虑雷电流的高频效应基础上,忽略导体的电阻,建立合理的双π型等效电路下的数学模型,对圆环接地网在冲击电流入地点处的电压用电磁暂态程序(ATP-EMTP)进行仿真,并将得到的结果与方孔接地网进行对比分析。在此模型的基础上,对影响冲击特性的其它因素进行仿真分析,并用仿真的方法对圆环接地网的冲击特性进行优化研究。分析结果表明：圆环形接地网雷电流冲击入地点处的电压只有方形接地网的二分之一左右。当雷电流冲击入地点位于圆环接地网中心位置时,其入地点处电压只有位于边缘处的三分之一左右。雷电流幅值升高时,冲击接地点处的电压也随之升高,并且随着雷电流幅值的增加,冲击点处电压随时间变化越快。不等间距同心圆环接地网在冲击入地点处的电压比等间距同心圆环接地网低13.3%左右。根据分析结果可得出以下结论：圆环接地网在降低冲击电流入地点处的电压方面比方孔地网好,在保护设备及人身安全方面效果明显。在接地网设计时,应该尽量将接地引下线布置在接地网的中心处,以降低冲击点处的电压,并应采用不等间距同心圆布置圆环接地网。
[Abstract]:Grounding system is one of the important components to ensure the safe operation of wind farm. The high potential of lightning impulse in the grounding grid is always one of the main problems that threaten the safety of equipments and people. In order to effectively reduce the voltage at the injection point of lightning impulse current in grounding grid and improve the impulse potential distribution of grounding grid, the impact characteristics of circular earthing grid in wind farm are studied and analyzed in this paper. In this paper, the geometric model of the toroidal grounding grid is first established, and then, on the basis of considering the high frequency effect of the lightning current, the resistance of the conductor is ignored, and a reasonable mathematical model of the double 蟺 equivalent circuit is established. The voltage of toroidal grounding grid is simulated by electromagnetic transient program (ATP-EMTP), and the results are compared with that of square hole grounding grid. On the basis of this model, the other factors affecting the impact characteristics are simulated and analyzed, and the impact characteristics of the ring grounding grid are optimized by the simulation method. The analysis results show that the current impact voltage of the circular grounding grid is only about 1/2 of that of the square grounding grid. When the lightning current impinges at the center of the ring grounding grid, the voltage at the incoming location is only about 1/3 of that at the edge. When the lightning current amplitude increases, the voltage at the impulse grounding point also increases, and with the increase of lightning current amplitude, the voltage at the impulse point changes faster with time. The voltage of the concentric ring grounding grid with unequal spacing is 13.3% lower than that of the concentric ring grounding grid with equal spacing at the impact site. According to the analysis results, the following conclusions can be drawn: the ring grounding grid is good in reducing the voltage of the impulse electric inflow site, such as the hole-to-ground network, and the effect is obvious in the protection of equipment and personal safety. In the design of the grounding grid, the grounding lead-down line should be arranged at the center of the grounding grid as far as possible to reduce the voltage at the impact point, and the ring grounding grid should be arranged with unequal spacing concentric circle.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614
本文编号：2471452
[Abstract]:Grounding system is one of the important components to ensure the safe operation of wind farm. The high potential of lightning impulse in the grounding grid is always one of the main problems that threaten the safety of equipments and people. In order to effectively reduce the voltage at the injection point of lightning impulse current in grounding grid and improve the impulse potential distribution of grounding grid, the impact characteristics of circular earthing grid in wind farm are studied and analyzed in this paper. In this paper, the geometric model of the toroidal grounding grid is first established, and then, on the basis of considering the high frequency effect of the lightning current, the resistance of the conductor is ignored, and a reasonable mathematical model of the double 蟺 equivalent circuit is established. The voltage of toroidal grounding grid is simulated by electromagnetic transient program (ATP-EMTP), and the results are compared with that of square hole grounding grid. On the basis of this model, the other factors affecting the impact characteristics are simulated and analyzed, and the impact characteristics of the ring grounding grid are optimized by the simulation method. The analysis results show that the current impact voltage of the circular grounding grid is only about 1/2 of that of the square grounding grid. When the lightning current impinges at the center of the ring grounding grid, the voltage at the incoming location is only about 1/3 of that at the edge. When the lightning current amplitude increases, the voltage at the impulse grounding point also increases, and with the increase of lightning current amplitude, the voltage at the impulse point changes faster with time. The voltage of the concentric ring grounding grid with unequal spacing is 13.3% lower than that of the concentric ring grounding grid with equal spacing at the impact site. According to the analysis results, the following conclusions can be drawn: the ring grounding grid is good in reducing the voltage of the impulse electric inflow site, such as the hole-to-ground network, and the effect is obvious in the protection of equipment and personal safety. In the design of the grounding grid, the grounding lead-down line should be arranged at the center of the grounding grid as far as possible to reduce the voltage at the impact point, and the ring grounding grid should be arranged with unequal spacing concentric circle.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614
【参考文献】
相关期刊论文 前1条
1 孙结中,刘力;运用等值复数镜像法求解复合分层土壤结构的格林函数[J];中国电机工程学报;2003年09期
，本文编号：2471452
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