Study on current reduction via ground into power generation systems near coast by controlling lightning surges due to high pressure gas phase

为了减少通过地面进入沿海发电系统的雷电电流，在高压干燥空气条件下，利用模拟海洋浸泡的建筑材料间隙进行了脉冲放电实验。研究结果如下：(1)在模拟海水浸泡砂浆间隙的情况下，使用KCl水溶液，放电波形为单极，放电阈值电压比干燥间隙降低33%；(2)在模拟海水浸泡在干燥空气中5atm以内的混凝土间隙中，放电发射模式在混凝土表面广泛扩展，峰值电流幅度也比干燥间隙减小47%，这意味着混凝土体积内的放电电阻随着气压的增加而增加。(3)认为该研究可应用于接地系统周围地区的雷电电流侵入。

To reduce the lightning current via the ground into power generation systems near the coast, the impulse discharge experiments have been performed using the building material gap soaked by a simulated sea under high-pressure dry-air conditions. The results are as follows; (1) in the case of mortar gap soaked by a simulated sea, using the KCl water solution, the discharge waveforms has unipolar ones and the discharge threshold voltage is reduced to 33 % compared with the dry gap, (2) in the case of concrete gap soaked by a simulated sea in dry-air within 5 atm, the discharge emission pattern widely expands on the concrete surface and the peak current amplitudes are also reduced to 47 % compared with the dry gap, where this means that discharge resistance in a concrete volume increases with increasing air pressures, and (3) it is considered that an application of the concerned study is available against lightning current invasion in the region surround a grounding system.