We investigated the mechanism by which a lightning strike generates overvoltage at a building's distribution board. We analyzed the overvoltage using Virtual Surge Test Lab (VSTL) electromagnetic analysis software and constructed a simplified mathematical model for calculating the overvoltage. The results confirmed that the overvoltage generated at the distribution board is not affected by the arrangement of the ground wires. The overvoltage is instead dominated by the potential difference between the ground electrodes, which is determined by the potential distribution in the surrounding ground. The overvoltage was calculated by the potential interferometry at steady state of the ground potential distribution. The calculated results of the overvoltages differed within ±10% from the analyzed results.

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考虑建筑物的接地线之间过电压的直接产生雷击的机理

我们研究了雷击在建筑物配电板上产生过电压的机制。我们使用虚拟浪涌测试实验室（VSTL）电磁分析软件分析了过电压，并构建了用于计算过电压的简化数学模型。结果证实，在配电板上产生的过电压不受接地线布置的影响。相反，过电压由接地电极之间的电位差决定，该电位差由周围地面中的电位分布确定。通过在地面电势分布的稳定状态下的电势干涉法计算出过电压。过电压的计算结果与分析结果相差±10％。