Stator coil and stator comprising said stator coil, rotating electrical machine, and manufacturing method for stator coil
An object is to provide a stator coil having a corner portion with less start points for partial discharge while reducing loss. A stator coil having a conductor bar includes, at a corner portion thereof: a first insulating layer covering an outer periphery of the conductor bar; an electric conductor having one end electrically connected to the conductor bar on a distal end side of the corner portion, and another end placed on an outer surface of the first insulating layer; a first conductive layer covering an outer periphery of the first insulating layer and the electric conductor located on the outer surface of the first insulating layer; a second insulating layer covering an outer periphery of the first conductive layer; and a second conductive layer covering an outer periphery of the second insulating layer.
1. A stator coil having a conductor bar, the stator coil comprising, at a corner portion thereof:
a first insulating layer covering an outer periphery of the conductor bar;
an electric conductor having one distal end electrically connected to the conductor bar on a distal end side of the corner portion, and another distal end placed on an outer surface of the first insulating layer;
a first conductive layer covering an outer periphery of the first insulating layer and the electric conductor located on the outer surface of the first insulating layer;
a second insulating layer covering an outer periphery of the first conductive layer; and
a second conductive layer covering an outer periphery of the second insulating layer,
wherein the first conductive layer does not form a helical current path.
2. The stator coil according to claim 1 , wherein
a surface resistivity of the first conductive layer and a surface resistivity of the second conductive layer are in a range of 10 2 Ω/□ to 10 5 Ω/□.
3. The stator coil according to claim 1 , wherein
the electric conductor is a metal tape having an adhesive layer.
4. The stator coil according to claim 1 , wherein
the conductor bar is formed by bundling strands each having a rectangular sectional shape, and
the electric conductor is connected to only one of the strands.
5. The stator coil according to claim 4 , wherein
a width of the electric conductor is not greater than widths of the strands.
6. A stator comprising:
an annular stator core having slots arranged in a circumferential shape; and
the stator coil according to claim 1 , inserted into the slots.
7. A rotating electrical machine comprising:
the stator according to claim 6 ; and
a rotor provided rotatably relative to the stator, on an inner circumferential side of the stator.
8. A manufacturing method for a stator coil, comprising the steps of:
covering an outer periphery of a conductor bar by a first insulating layer;
electrically connecting one distal end of an electric conductor to the conductor bar, on a distal end side of a corner portion of the conductor bar, and placing another distal end of the electric conductor on an outer surface of the first insulating layer;
covering an outer periphery of the first insulating layer and the electric conductor located on the outer surface of the first insulating layer, by a first conductive layer;
covering an outer periphery of the first conductive layer by a second insulating layer; and
covering an outer periphery of the second insulating layer by a second conductive layer,
wherein the first conductive layer does not form a helical current path.