The investigation for the microscopic state and situation of water molecules in dielectric materials

The investigation for conduction and breakdown phenomena in liquid has developed many important theories and has implemented measurement techniques. However, it is difficult to apply these theories to insulating liquids used for power apparatus, because these liquids include some impurities and additives, and the structure of the liquids is complicated. The investigation must be adapted to the actual insulating liquids used for power apparatus. For insulating liquids used for power apparatus, the effects of impurities, especially “water” is the most important problem, but there was no way to understand the behavior of these impurities in the insulating liquid. However the situation or state of water in bulk water and many matrix liquids have been studied. In these studies, the states and hydrogen bonding array structure of water was discussed in microscopic detail, and these results can be applied to the insulating liquid. This paper summarizes the topics of the investigation for conduction and breakdown phenomena, studies for effect of water in insulating liquid, and studies for characteristics of water. Moreover, the latest investigation of water cluster structure in matrix liquid and its effect on electronic conduction phenomena are presented