Hitachi, Ltd.

Minoru Hoshi

Etsunori Mori

Masaru Higaki

Atsushi Miki

Masaru Watanabe

Shigeo Kikuchi

A winding for a static induction apparatus such as a transformer, a reactor and the like comprises a plurality of interleaved coils each formed by winding an electrically insulated strand conductor in a radial spiral. The coils are stacked axially and electrically connected in series between a line terminal and another terminal such as a neutral terminal. The winding is divided into a plurality of blocks each including a plurality of ones of the interleaved coils. The number of turns of each coil belonging to the block on the other terminal side is decreased as compared with that of each coil belonging to the block located closer to the line terminal, to thereby reduce the series electrostatic capacitance of the coils stepwise from one to another block starting from the one located on the line terminal side. The distribution constant is thus decreased. Favorable surge withstanding characteristics are attained, reliable insulation is assured and the winding can be realized in a reduced size.

Winding for static induction apparatus

An on-load tap-changing transformer in which its high-voltage winding is axially divided into parallel-connected halves, and an end conductor constituting part of the high-voltage winding is connected to the other terminal of each of the halves. A coarse tap coil connected by the end conductor to the other terminal of each of the halves of the high-voltage winding is disposed adjacent to the associated half, and a fine tap coil connected to the coarse tap coil through a coarse tap selector used for the change-over of the tap position to the taps of the coarse tap coil is disposed at a radial position spaced apart from the coarse tap coil. The end conductor is wound together with the conductors of the fine tap coil.

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Hitachi, Japan

Minoru Hoshi