Fundamental study on ultimate utilization of the substance co-existing in nature to insulation of electrical apparatus

本研究旨在提出有效使用环保物质的电力设备最佳绝缘设计方案。随着非接触式电场和电子密度测量技术的发展，需要对绝缘状况进行评估，本文提出了两种测量方法。建立了一种基于Shack-Hartmann法的激光波前传感器，用于测量空气中放电电子密度。用带微透镜阵列的快速门控ICCD相机测量了两束激光在同一光程上通过放电的波前。使用该传感器，可以测量放电的电子密度分布，而不会引起任何场干扰。基于克尔效应，提出了一种气体电场的非接触式测量方法。利用该测量技术，成功地测量了大气中交流应力均匀电场和非均匀电场。此外，还发现放电产生的离子具有非常大的克尔效应，这为测量气体中离子密度提供了一种新的方法。SF_6气体具有较高的全球变暖潜势，是限制气体之一。因此，近年来人们对SF_6的替代绝缘气体进行了大量的研究。本研究对SF_6替代品之一的CF_3I气体进行了研究。通过测量具有不同电场利用系数的不同电极几何形状的火花放电电压，考察了CF_3I和SF_6的绝缘性能。在均匀电场条件下，CF_3I气体的火花击穿电压比SF_6气体高1.2倍。另一方面，在极不均匀场条件下，CF_3I气体比SF_6气体低0.7倍。电场利用系数在0.3 ~ 0.4范围内时，CF_3I气体的绝缘性能与SF_6气体的绝缘性能基本相等。少

This study has been made aiming at the proposal of optimum insulation design of power apparatus in which environmentally-friendly substance is effectively used. As the development, of noncontact measurement technique of electric field and electron density is required for evaluating the insulation condition, two measurement, methods are proposed in the report.A laser wavefront sensor based on the Shack-Hartmann method is constructed for measuring electron density of discharge in air. The wavefronts of two lasers passing through the discharge on a same optical path are measured by fast-gated ICCD cameras with micro-lens arrays. With this sensor, electron density distribution of discharge can be measured without causing any field disturbance.A noncontact measurement of electric field in gases has been developed based on the Kerr effect by the authors. With this measurement technique, ac stressed uniform and non-uniform electric fields in atmospheric air are successfully measured. It is al … More so found that ions generated due to electrical discharges may have very large Kerr effect and this fact may provide with a new method for measuring ion densities in gas.SF_6 gas has high global-warming-potential and is one of the gases for the restriction. Therefore, many researches of alternative insulating gases to SF_6 have been actively done in recent years. In this research, CF_3I gas, which is one of promising SF_6 substitutions, is examined. The insulation performance of CF_3I and SF_6 is examined through measuring sparkover voltage of various electrode geometries which have different electric-field utilization factors. The sparkover voltage for CF_3I gas is 1.2 times higher than that for SF_6 gas under a uniform electric-field condition. On the other hand, under an extremely non-uniform field condition, that for CF_3I gas is 0.7 times lower than SF_6 gas. The insulation property of CF_3I gas becomes almost equal to that of SF_6 gas when the electric-field utilization factor is in the range of 0.3 to 0.4. Less