Low stray-loss transformers and methods of assembling the same
A transformer includes a magnetic core, a first winding assembly inductively coupled to the magnetic core, and a second winding assembly inductively coupled to the first winding assembly. The magnetic core includes a winding leg. The first winding assembly includes a plurality of first layers, and the second winding assembly includes a plurality of second layers. The first and second winding assemblies are concentrically wound around the winding leg in an interleaved configuration, where at least one of the plurality of second layers is disposed between two of the plurality of first layers, and at least one of the plurality of first layers is disposed between two of the plurality of second layers.
1. A transformer comprising:
a magnetic core comprising a winding leg;
a first winding assembly having a first magnetic length, a first axial length, and a plurality of first layers, said first winding assembly inductively coupled to said magnetic core; and
a second winding assembly inductively coupled to said first winding assembly, said second winding assembly having a second magnetic length substantially equal to said first magnetic length, and a second axial length different from the first axial length, said second winding assembly comprising a plurality of second layers, wherein said first and second winding assemblies are concentrically wound around said winding leg in an interleaved configuration,
wherein at least one of said plurality of second layers is disposed between two of said plurality of first layers, and at least one of said plurality of first layers is disposed between two of said plurality of second layers,
wherein the number of layers in the first plurality of layers is different than the number of layers in the second plurality of layers.
2. A transformer in accordance with claim 1 , wherein each of said first layers comprises at least one first conductive conduit helically wound around said winding leg, and each of said layers comprises at least one second conductive conduit helically wound around said winding leg.
3. A transformer in accordance with claim 2 , wherein each of said first and second conductive conduits comprises insulated copper wiring.
4. A transformer in accordance with claim 1 , wherein each of said first and second layers are separated by at least one insulating layer.
5. A transformer in accordance with claim 1 , wherein each said first and second winding assemblies are coaxially aligned with a longitudinal axis of said winding leg.
6. A transformer in accordance with claim 1 , wherein said plurality of second layers are wound in pairs of adjacent second layers, wherein none of said plurality of first layers is disposed between said adjacent second layers forming said pairs of adjacent second layers, and wherein at least two of said plurality of first layers are disposed between adjacent pairs of said pairs of adjacent second layers.
7. A transformer in accordance with claim 1 , wherein said winding leg is a first leg of said magnetic core, said magnetic core further comprising a second leg, said first and second winding assemblies extending between said first and second legs of said magnetic core.
8. The transformer of claim 1 , wherein said first and second magnetic lengths are less than corresponding said first and second axial lengths.
9. A method of assembling a transformer, said method comprising:
providing a magnetic core including a winding leg;
providing a first winding assembly including a plurality of first layers, a first magnetic length, and a first axial length;
providing a second winding assembly including a plurality of second layers, a second magnetic length equal to the first magnetic length, a second axial length different from the first axial length; and
concentrically winding the first and second winding assemblies around the winding leg of the magnetic core in an interleaved configuration such that at least one of the plurality of second layers is disposed between two of the plurality of first layers, and at least one of the plurality of first layers is disposed between two of the plurality of second layers, and the number of layers in the first plurality of layers is different than the number of layers in the second plurality of layers.
10. A method in accordance with claim 9 , wherein each of the first layers includes at least one first conductive conduit, each of the second layers includes at least one second conductive conduit, and concentrically winding the first and second winding assemblies around the winding leg of the magnetic core comprises helically winding the first and second conductive conduits around the winding leg of the magnetic core in an alternating pattern such that each second layer is disposed between at least two adjacent first layers.
11. A method in accordance with claim 9 , wherein the first and second winding assemblies are wound such that each of the first and second layers are separated by an insulating layer.
12. A method in accordance with claim 9 , wherein concentrically winding the first and second winding assemblies around the winding leg of the magnetic core comprises winding the second layers in pairs of adjacent second layers such that none of the plurality of first layers is disposed between the adjacent second layers forming the pairs of adjacent second layers, and at least two of the plurality of first layers are disposed between adjacent pairs of the pairs of adjacent second layers.
13. The method of claim 9 , wherein concentrically winding the first and second winding assemblies around the winding leg of the magnetic core further includes the number of layers in the first plurality of layers is different than the number of layers in the second plurality of layers.