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

本研究是针对有效利用环保物质的电力设备绝缘优化设计的建议而进行的。随着非接触式电场和电子密度测量技术的发展对绝缘状态的评价提出了两种测量方法。基于夏克-哈特曼方法，构建了一种测量空气中放电电子密度的激光波前传感器。用带微透镜阵列的快门ICCD相机测量了同一光路上通过放电的两个激光器的波前。该传感器可以在不产生任何电场扰动的情况下测量放电的电子密度分布。作者基于克尔效应发展了一种非接触测量气体中电场的方法。利用这种测量技术，成功地测量了大气中交流应力均匀电场和非均匀电场。这是al…进一步发现，电场放电产生的离子可能具有很大的克尔效应，这一事实可能为测量气体中的离子密度提供了一种新的方法。SF_6气体具有很高的全球变暖势，是限制气体中离子密度的气体之一。因此，近年来对SF_6替代绝缘气的研究十分活跃。在本研究中，我们考察了一种很有前途的SF_6替代品--CF_3I气体。通过测量具有不同电场利用率的不同电极几何形状的闪络电压，考察了CF3I和SF6的绝缘性能。在均匀电场条件下，CF3I气体的闪络电压是SF6气体的1.2倍。另一方面，在极不均匀的场强条件下，CF3I气体比SF6气体低0.7倍。电场利用率在0.3~0.4时，CF3I气体的绝缘性能与SF6气体的绝缘性能基本相同。较少

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