JP3362973B2 - Winding rotor coil - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine, and more particularly to a wound rotor coil incorporated in a variable speed pumped generator. 2. Description of the Related Art In a variable speed pumping generator, a wound rotor coil is employed, so that a centrifugal force acting at the time of operation is different from that of a normal turbine generator in winding. Need to be fixed. [0003] Rotor coil 1 of conventional variable speed pumped generator
As shown in FIGS. 7 and 8, after the coil linear portion 3 is placed in the slot of the rotor core 2, it is fixed by a slot wedge (not shown). Further, a rotor coil end portion 4 protruding outward from an end of the rotor core 2 of the rotor coil 1 is provided with a support ring 5 connected and fixed to an end of the rotor core 2 and a rotor coil end portion 4. , And between the rotor coil end portions 4, and the like. A bind cord 7 such as nonmagnetic steel or glass fiber impregnated with a thermosetting resin is wound around the outer peripheral surface of the end of the rotor coil end portion 4. An insulating layer 9 is provided on the outer surface of the conductor 8. In the rotor coil having the above structure, the centrifugal force acting on the rotor coil end portion 4 during operation is transmitted to the bind cord 7 via the insulating spacer 6, so that the rotation Child coil end part 4 and insulating spacer 6
Compressive stress is generated at the interface with. This compressive stress is not uniform on the outer peripheral surface of the rotor coil end portion 4 but is highest at the outer peripheral corner of the cross section.
It becomes larger as the radius of curvature of the corner of the conductor 8 of the rotor coil end portion 4 becomes smaller. Furthermore, the bind cord 7 and the insulating spacer 6 after the winding are not strictly a perfect circle,
The polygonal shape inscribed in the outer peripheral surface of the rotor coil end portion 4 also contributes to the concentration of compressive stress. When the variable speed pumping generator is a large variable speed pumping generator having a large rotor diameter and a high peripheral speed, the centrifugal force acting on the rotor coil end portion 4 is increased. For this reason, the insulating layer 9 applied to the corners of the conductor 8 of the rotor coil end portion 4 may be mechanically damaged, and the electric strength may be reduced. The present invention has been made in view of the above points, and has a sufficient reliability with respect to centrifugal force acting on a large-diameter, high-peripheral-speed rotor coil such as a large variable-speed pumping generator. It is an object of the present invention to provide a rotor coil of a rotating electric machine that can ensure the performance. [0007] In the wound type rotor coil of the present invention, a coil linear portion is accommodated in a slot of a rotor core, and a coil end portion projecting outward from an end of the core is supported. In the wound rotor supported and fixed by the device, the coil conductor is composed of a plurality of strands, and the radius of curvature of the strand disposed at the outer peripheral corner of the conductor at the coil end portion is set to the radius of curvature of the other strand. It is characterized in that it is larger than the radius of curvature of the corner. In the wound rotor coil according to the present invention, the compressive stress concentrated on the insulating layer applied to the corner of the conductor at the coil end can be reduced, and a large-diameter variable-speed pump generator such as a large-sized variable-speed pumping generator can be used. Also, sufficient reliability can be ensured even with respect to centrifugal force acting on a high peripheral speed rotor coil. An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, the same members as those in FIGS. 7 and 8 are denoted by the same reference numerals. FIGS. 1 to 3 show an embodiment of a wound rotor coil according to the present invention.
Numeral 0 designates a coil straight portion 14 which is accommodated in a rotor slot (not shown) provided in the rotor core 11 and is fixedly supported by slot wedges, comprising a solid conductor 12 having a small radius of curvature and an insulating layer 13; The solid conductor 15 having a large radius of curvature and the coil end portion 17 made of the insulating layer 16 are electrically and mechanically connected near the slot exit. As described above, the conductor 1 of the coil end portion 17
By increasing the radius of curvature of the corners facing the insulating spacer 6 of FIG. 5 from the conventional one, stress concentration on the insulating layer 16 is reduced. Even if the insulating layer 16 is formed of the same material as the conventional insulating layer, it can be applied to a rotor having a larger diameter and a higher peripheral speed. The coil straight section 14 may be formed of a label transposition conductor composed of a plurality of strands. The conductor 15 of the coil end portion 17
Only by making the corner radius of curvature larger than that of the conventional one, the compressive stress concentrated on the insulating layer 16 applied to the corner of the conductor 15 of the coil end portion 17 can be reduced.
Can be more reliable against damage. In addition, by keeping the radius of curvature of the corner of the conductor 12 of the coil straight portion 14 unchanged, the space factor of the conductor in the rotor slot does not decrease. FIGS. 4 to 6 show modifications of the wound rotor coil according to the present invention. In the modifications shown in FIGS. 4 and 5, the rotor coil 10 made of a continuous solid conductor having a small corner radius of curvature is used. Only the corner 15a of the conductor 15 corresponding to the coil end 17 is largely finished by machining. This machining may be performed only on two corners on the outer peripheral side of the conductor 15a, or may be performed on all four corners on the outer peripheral side and the inner peripheral side. With such a configuration, the operation of connecting conductors having two kinds of cross-sectional shapes can be omitted, and the present invention can be applied to a rotor having a larger diameter and a higher peripheral speed even if the insulating layer is made of the same material as the conventional one. it can.
By machining the corner 15a of the conductor 15, the cross-sectional area of the conductor of the coil end portion 17 becomes smaller than that of the coil straight portion 14, but the cooling condition of the coil end portion 17 is better than that of the coil straight portion 14, so that the temperature rise No problems from In the modified example shown in FIG. 6, among the plurality of wires 18 constituting the continuous label transposition conductor 17, at least the corner curvature of the wire 18a arranged at the outer corner of the conductor of the coil end portion 17 is provided. The radius is larger than that of the other strands 18. With such a configuration, the continuous label transposition conductor 17 that does not significantly reduce the space factor of the conductor in the rotor slot and does not require connection work or machining is provided with an insulating layer of the same material as the conventional one. By applying No. 16, a rotor coil suitable for a rotor having a larger diameter and a higher peripheral speed can be obtained. The wound rotor coil according to the present invention has a coil conductor composed of a plurality of wires, and a corner radius of curvature of the wire disposed at the outer corner of the conductor at the coil end. Is larger than the radius of curvature of the corners of the other wires, the compressive stress concentrated on the insulating layer applied to the conductor corners of the coil end can be reduced, and large diameters such as large variable speed pumped generators can be obtained. Also, sufficient reliability can be ensured even with respect to centrifugal force acting on a high peripheral speed rotor coil.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional view of a wound rotor coil according to the present invention. FIG. 2 is a sectional view taken along the line AA of FIG. 1; FIG. 3 is a sectional view taken along the line BB of FIG. 1; FIG. 4 is a sectional view showing a conductor of a coil end portion of a first modification of the wound rotor coil according to the present invention. FIG. 5 is a sectional view showing a conductor of a coil straight portion of a first modification of the wound rotor coil according to the present invention. FIG. 6 is a sectional view showing a conductor at a coil end portion of a second modification of the wound rotor coil according to the present invention. FIG. 7 is a partial cross-sectional view of a conventional wound rotor coil. FIG. 8 is a sectional view taken along the line CC of FIG. 7; [Description of Signs] 5 Support ring 6 Insulating spacer 7 Bind cord 10 Rotor coil 11 Rotor core 14 Coil linear portion 15 Conductor 15a Conductor corner 16 Insulating layer 17 Coil end 18 Elementary wire

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02K 3/00-3/52

Claims (1)

(1) A winding type in which a coil linear portion is accommodated in a slot of a rotor core, and a coil end portion protruding outward from an end of the core is supported and fixed by a support device. In the rotor, the coil conductor is composed of a plurality of strands, and the radius of curvature of the strand disposed at the outer peripheral corner of the conductor at the coil end portion is larger than the radius of curvature of the other strand. A wound-type rotor coil characterized by the following.