JPH01274633A - Insulating unit for field winding of electrical rotary machine - Google Patents

Abstract

PURPOSE:To prevent breakdown a layer of insulating member and to prevent layer shortcircuit, by employing a layer insulating member having cushion performance and low compression resiliency. CONSTITUTION:A layer insulating member 44 is arranged between the end-of- winding 42 of a winding conductor brazed to a lead wire 13 and the winding conductor 43 in second layer. A cover insulating member 41 prepared by forming a heat-resistant electrical insulating polyamide paper having cushion performance and low compression resiliency into U-shape and contacting with the lamination side of the winding conductor connected with the lead wire 13 and the opposite side faces is employed as the layer insulation member 44. By such arrangement, breakdown of the layer insulation due to local contact of winding conductors caused by buckling of the lead wire can be prevented, resulting in prevention of layer shortcircuit due to mutual shift of winding conductor layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an insulating device for a field winding of a cylindrical rotor such as a turbine generator, etc.
The present invention relates to a field winding insulating device suitable for interlayer insulation of winding conductor winding ends connected to lead wires.

[Conventional technology]

Generally, a rotor of a turbine generator or the like has a cylindrical iron core, and the rotor field winding 3 is housed in a longitudinal slot provided along the outer circumference of the rotor. The field winding consists of a conductor that is placed at the bottom of the pair of slots closest to the magnetic surface and then passed through the primary winding until it reaches a position near the top of the slot. The wire layers are helically stacked into a pair of slots. The stacked windings are shown in FIGS. 2-5, and then similar windings are continued in the next pair of rotor slots, and such winding scheme is repeated for the desired number of slot pairs. will be returned. Similarly, current flow through these windings follows the conductive paths described above.

Electricity is supplied to these windings from the current collection ring through the lead wire 13. The conductors are typically flat conductor rods of copper, so that the rotor pole windings 3 are kept wound in series by being placed between layers of copper adjacent to the insulation layer. . In addition, in large generators, in order to increase the cooling effect, holes are provided along the length of the conductor rods in the slots according to the cooling method, and the holes provided in each conductor rod are adjacent to each other. The holes in the conductor rods are aligned to form suitable cooling passages. For the area outside the slot of the rotor winding, copper conductor strips connected in parallel to the rotor field winding 3 are used, grooves are provided in each conductor rod, and cooling passages are created by aligning the grooves of the conductor rods with each other. It is being formed.

The lead wire 13 that supplies electricity to the windings is housed in a slot 31 provided in the longitudinal direction of the rotor shaft, and one end is connected by brazing to the end of the winding closest to the center. , and the other end is connected by bolting to a center hole conductor passing through a through hole provided at the axis of the rotor shaft from the current collecting ring. Furthermore, since the lead wire 13 receives centrifugal force due to the rotation of the rotor 1,
A wedge for holding this is the lead wire 1 in the slot 31.
It is attached to the top of 3. There are two types of lead wires; one is a flexible type formed by stacking multiple thin conductive plates, and the other is an integrated solid type.

[Problem to be solved by the invention]

In the above conventional structure, in the flexible type lead wire, the rising part of the lead wire that comes out of the slot and is connected to the winding end of the winding is buckled and deformed due to centrifugal force during operation, and as a result, the lead wire is not connected to the lead wire. The winding end of the winding tilts and comes into contact with the winding conductor of the upper second layer, and the centrifugal force of the rising part of the lead wire concentrates on this part, causing the wire to be inserted between the layers. Recently, attention has been drawn to the problem that damage to interlayer insulation materials can occur. However, there was a problem in that it was easy to break due to this phenomenon, leading to an interlayer short circuit accident.Also, in the same way, a combination of a solid type lead wire 13 and a field winding 3 provided with cooling ventilation holes 23 was used. In this case, the centrifugal force of the rising part of the Hitachi wire during operation is applied directly to the winding conductor stacked on top, crushing the cooling ventilation holes 23 provided in this winding conductor, and causing the winding conductor to taper. It has also come to be noticed that there is a problem in which the conductors are deformed and the conductors are pushed out, causing relative misalignment between the conductors.This is because conventional interlayer insulation methods A structure in which glabellar insulation with a 100% glabella is bonded to one conductor is often used, and if there is relative misalignment between the conductors, the structure is likely to cause short circuits between the layers.

An object of the present invention is to provide a novel field winding insulating device that prevents such dielectric breakdown due to local contact between winding conductor layers and interlayer short circuit due to relative misalignment, and has a long life. .

In Figure 1, 4 is the field winding retaining ring, 12 is the magnetic pole center, and 14 is the field winding retaining ring.
is the winding wire, 30 is the rotor core, 21°22 is the thin layer,
24 is an insulator, 33 is a lead wire wedge, and 34 is a terminal bolt.

[Means to solve the problem]

The above purpose is to use electrical insulating material folded in a flexible manner with a small compressive modulus along the end of the winding with a width exceeding the width of the end of the winding as an interlayer insulation to be bonded to the end of the winding conductor connected to the lead wire. This is achieved by using a cover insulation with a similar shape.

[Effect]

The interlayer insulating material having a cushioning function and having a small compressive elastic modulus relieves concentrated compressive stress caused by local contact with the winding conductor.

Thereby, damage to the interlayer insulation material can be reduced and interlayer short circuits can be prevented.

The interlayer insulating material having a width exceeding the width of the winding end conductor and extending along the winding end covers and insulates the winding end conductor connected to the lead wire. Thereby, even if relative misalignment occurs between the conductors, interlayer short circuits can be prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. Winding end 4 of the winding conductor connected to the lead wire 13 by brazing
2 and the second layer winding conductor 43, a heat-resistant electrically insulating polyamide paper (for example, Nomex manufactured by DuPont) with a cushioning function and a small compressive elastic modulus is used as an interlayer insulating material 44 as an electrical insulator between A cover insulating material 41 is provided on the winding stack side and both side surfaces of the winding conductor 42 which is connected to the lead wire 13 in the shape of a letter.

According to this embodiment, the first lead wire 13 is buckled and deformed, and the winding conductor 42 connected thereto is tilted, causing local contact with the second layer winding conductor 43, and compressive concentrated stress is generated. However, due to the cushioning effect of the cover insulating material 41, concentrated stress is alleviated, damage can be reduced, and interlayer short circuit can be prevented. Furthermore, according to this method, even if a relative shift occurs between the winding conductor 42 connected to the lead wire and the winding conductor 43 of the second layer due to differences in thermal expansion during operation, there will be no interlayer short circuit. You can prevent it from happening. Although this example shows a case where the winding conductor 42 connected to the lead wire is insulated with a cover, the winding conductor 43 of the second layer may be insulated with a cover.

Further, in this example, cover insulation is provided over the entire length of the winding conductor 43 in the length direction, but cover insulation may be provided locally, for example, at a portion connected to a lead wire.

〔Effect of the invention〕

According to the present invention, it is possible to prevent damage to the interlayer insulation due to contact between the winding conductors due to buckling deformation of the lead wire.
This prevents short-circuit accidents between the eyebrows due to relative misalignment between the winding conductor layers.

[Brief explanation of the drawing]

FIG. 1(a) is a perspective view of one embodiment of the present invention, and FIG. 1(b) is a perspective view of an embodiment of the present invention.
) is its side view, Figure 2 is a perspective view of the turbine generator rotor, Figure 3 is a perspective view of the field winding installed in a pair of rotor slots, and Figure 4 (a) is the cooling ventilation. Side view showing the slot external winding structure when holes are provided, FIG. 4(b)
is its plan view. FIG. 5 is a longitudinal cross-sectional view of a rotor opening showing the background of the present invention. 1... Rotor, 3... Field winding, 4... Field winding retaining ring. 44...Interlayer insulation. ml Figure (cLnζb) Figure 2 3θ Figure 3 ″

Claims (1)

[Scope of Claims] 1. A cylindrical iron core having slots in the longitudinal direction along the outer periphery, a plurality of series-connected conductive windings arranged in layers within the slots, and the conductive windings. and a lead wire connected to the winding end of the conductive winding for supplying electricity from the current collecting ring, and the layers are connected in series by an electrical insulator disposed between the layers. In the rotor that is maintained, an interlayer in which an electrical insulator having a width exceeding the width of the winding end is placed along the winding end of the conductive winding connected to the lead wire. An insulating device for a field winding of a rotating electrical machine, characterized by being provided with an insulator. 2. The insulating device for a field winding of a rotating electric machine as set forth in claim 1, wherein the interlayer insulator is a flexible material having a cushioning function.