Kenichiro Soma

Development of bow-tie tree inhibitor

The state of water in the crosslinked polyethylene insulation subjected to an electrical stress is discussed experimentally and theoretically, and it is concluded that the water vapor condenses by the stress. In consideration of experimental results of the relation between the electrical condensation of water and the generation of bow-tie trees, a generation mechanism of bow-tie trees is proposed. It is expected by the mechanism that the improvement of wettability of the materials may inhibit the generation of bow-tie trees. This consideration introduces new additives. The effect of the additives is examined by slub tests and cable tests. In conclusion, the additives decrease the generation number of bow-tie trees, shorten the lengths, and also suppress the change of the number and the lengths with aging time.