| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a current transformer which can be attached to a GIS, etc., without requiring measures for suppressing higher harmonics or work for preventing the occurrence of a short circuit between dummy winding terminals, and at the same time, satisfies both a residual magnetism characteristic and a residual current characteristic, while its main body is made more compact. SOLUTION: A current transformer is provided with a composite core 3, formed by coaxially arranging a core 1 having a void and a closed core 2 by bringing the cores 1 and 2 into contact with each other, a secondary winding N2 wound around the core 3, and a zero-phase ternary winding N3 which is wound around the core 3 to constitute an opened delta connection by connecting three phases of windings in series. The composite core 3 is constituted by using grain-oriented silicon steel. The secondary winding N2 is wound on the zero- phase ternary winding N3 after the winding N2 is wound around the core 3, and then thermosetting insulating tape is wound on the secondary winding N2.</p> |
