@article{oai:nagoya.repo.nii.ac.jp:00005290,
 author = {Okubo, H. and Shimizu, R. and Sawada, A. and Kato, K. and Hayakawa, N. and Hikita, M.},
 issue = {1},
 journal = {IEEE Transactions on Dielectrics and Electrical Insulation [see also IEEE Transactions on Electrical Insulation]},
 month = {Feb},
 note = {We measured the electric field in transformer oil/solid composite insulation system under dc voltage application using a Kerr electro-optic measurement system. When a press-board was inserted at the center between two parallel-plane electrodes, the electric field at the mid-point between the pressboard and the cathode decreased with time. On the other hand, the electric field at the mid-point between the pressboard and the anode increased initially with time, reached a maximum value and then fell down. We measured also the electric field before and afterpolarity reversal of the dc voltage. The results revealed that the electric field after polarity reversal reached a magnitude 2.7× as much as the average dc applied field. We interpreted the above results on the time transition of the electric field in terms of a charge dynamic model, considering the difference in chargeaccumulation speed on the preddboard between positive and negative charges. This model was verified to be applicable to the time transition of the electric field in oil/solid composite system and BTA added oil/solid composite system as well.},
 pages = {64--70},
 title = {Kerr electro-optic field measurement and charge dynamics in transformer-oil/solid composite insulation systems},
 volume = {4},
 year = {1997}
}