| 摘要 |
<p>A polyphase sector type transformer includes one magnetic core ring per phase, each of which has two rectilinear sides which are adjacent to each other. Each rectilinear side of one magnetic core ring is disposed contiguously with one of the rectilinear sides of an adjacent core ring whereby each magnetic core ring occupies a sector of the magnetic circuit of the transformer. Each pair of contiguous rectilinear sides is threaded through a coil of the transformer said coils comprising a high tension winding of trapezoidal cross-section and a low tension winding of rectangular cross-section. Each magnetic core ring is symmetrical about the plane of symmetry of the two coils which it threads; comprises an assembly of two generally arcuate parts arranged to facilitate threading of the coils on the rectilinear sides before the said core parts are joined by adhesive, the parts being separated along a plane perpendicular to the said plane of symmetry by sawing and; is made of a binder-impregnated, laminar stack of magnetic sheets of at least two different widths such that two contiguous rectilinear sides of two adjacent cores threading a single coil combine to give a magnetic circuit within the coil having a right cross-section which includes steps at the changes from one thickness of sheet to another and thereby forms a closer approximation to an ellipse than would a rectangular made from magnetic sheets all of the same width.</p> |
