Walking Electrification on Floor of High-Rise Building and Reduction Method of Human-Body Potential

由于静电放电（ESD）事件，高科技信息设备的电磁干扰（EMI）何时可能发生几乎是不可能预测的。特别是在高层智能建筑中，高分子材料和空调设备的广泛使用促进了电磁干扰的发生，带来了严重的情况。2001年至2002年，我们获得了补助金，用于科普上述问题的科学研究。阐明了高层建筑地面行走带电的机理，定量掌握了人体电位的衰减特性，为ESD事件引起的EMI提供了有效的预防手段。本研究获得的结果概述如下：2001年，我们提出了一种新的等效电路模型来预测地板上感应电荷引起的地板表面电位，并验证了其有效性。为 ...更多信息 迄今为止从未测量过的足迹表面电位，我们尝试用新开发的二维足迹表面电位测量仪来测量它们，该测量仪包括放置在市售电位仪的线上。将实测的踏面电位波形与用等效电路模型推导的公式计算的踏面电位波形进行比较，发现踏面电位随时间的变化趋势与计算结果一致。这一发现意味着等效电路模型不仅可以预测从鞋底落地到地板表面的电荷泄漏，而且还可以预测鞋子踢地板时在脚步上感应的地板电荷的泄漏过程。然而，由于在这里开发的脚踏表面电位计的工作故障，我们不能准确地获得表面电位，这使得我们不能确认所提出的等效电路模型的定量验证。改进了脚踏式表面电位计，并通过与实验测量结果的比较，验证了该等效电路对地板上电荷泄漏过程的有效性。地板表面电位首先在拉普拉斯域中导出了带电HB踢地板时的脚步表面电势的方程，并通过数值逆拉普拉斯变换计算了电势。此外，我们同时测量HB和足迹表面电位，改变HB充电电压。比较测量的电位波形与从等效电路模型计算的那些，我们发现，有很好的协议之间的测量和计算的HB电位归一化到HB充电电压的衰减特性。另一方面，测量的衰减特性的足迹表面电位归一化到其初始电位近似同意与计算的结果，无论HB充电电压，而我们观察到，有一些测量和计算的初始足迹表面电位之间的差异，而且测量的电位并不总是成比例的HB充电电压。这可能是因为在踢地板时，鞋底与地板之间产生电荷，使地板电容充电，从而改变地板电位，未来的课题是定量地掌握由于在地板上行走而产生的电荷及其动态时间行为。少

It is almost impossible to predict when the electromagnetic interferences (EMIs) of high-tech information equipment due to an event of electrostatic discharge (ESD) may happen. Particularly in the high-rise intelligence buildings, the wide use of high-polymers and air-conditioning facilities promotes such the EMI occurrence, which has brought about serious situations. We received grant-in-aids from 2001 to 2002 for scientific research to cope with the above-mentioned problem. As a result, we elucidated the mechanism of walking electrification on the floor of high-rise buildings, and grasped quantitatively the attenuation characteristics of human-body (HB) potential, which leads to providing effectively preventive means against EMIs caused by ESD events. The outline of the findings obtained in this study is as follows.In 2001, we proposed a new equivalent circuit model in order to predict the floor surface potential due to the induced charges on the floor, and verified its validity. For … More the footstep surface potentials that have never been measured so far, we tried to measure them with a newly developed measurement meter of two-dimensional footstep surface potentials, which consists of placement in line of commercially available potential meters. Comparing the measured waveforms of the footstep surface potential with those calculated using the equations derived from the equivalent circuit model, we found that the time change of the measured surface potential after the floor kick has the same trend as the calculated one. This finding implies that the equivalent circuit model can predict not only charge leak to the floor surface from the shoe sole landing on the floor but also leak process fo floor charges induced on the footstep for the shoe kicking the floor. Due to working failure of the footstep surface potential meter developed here, however, we could not obtain accurately the surface potentials, which did not enable us to confirm the quantitative verification of the proposed equivalent circuit model.In 2002, we improved the footstep surface potential meter and investigated the validity of the equivalent circuit for the charge leak process on the floor in comparison with the measurement of the floor surface potential. We first derived an equation in the Laplace domain for the footstep surface potential when the charged HB kicks the floor, and calculated the potential from the numerical inverse Laplace transformation. Also we measured simultaneously the HB and footstep surface potentials, changing the HB charge voltage. Comparing the measured potential waveforms with those calculated form the equivalent circuit model, we found that there is good agreement between the measured and calculated attenuation characteristics of the HB potential nomalized to the HB charge voltage. On the other hand, the measured attenuation characteristics of the footstep surface potential normalized to its initial potential approximately agreed with the calculated results regardless of the HB charge voltages, while we observed that there are some discrepancies between the measured and calculated initial footstep surface potentials and also that the measured potentials are not always proportional to the HB charge voltages. This may be because when kicking the floor, the charge occurs between the shoe sole and floor and it charges the floor capacitance, which results in changing the floor potential.The future subject is to grasp quantitatively the charge appearing due to walking on the floor and its dynamic time behavior. Less