JPH01152938A - Winding of rotary electric machine - Google Patents

Abstract

PURPOSE:To make it possible to control the potential uniformly over the full length of a shielding layer without damaging any insulation efficiency between stands by making at least one strand of a bundle of strands constituting a conductor a bare strand with no strand coating. CONSTITUTION:A conductor 2 transposes a bundle of strands 3 constituted of one base strand 3a with no strand coating and the other strand 3b with strand coating at a slot section of a rotary machine, inserts a vertical separator 5 as an insulation between strand rows, and fills a filler 6 in a transposition section to form a moulding. A shielding layer 1 is formed by winding a semiconductive tape 4 around the periphery of the conductor 2 continuously. In addition, a ground insulation 7 is formed on the periphery thereof. According to the constitution, the potential of the shielding layer 1 can be controlled uniformly over the length.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a winding of a large-scale high-voltage rotating electric machine such as a turbine generator, and particularly relates to a shield layer for controlling the internal potential of the coil. The present invention relates to a rotating electric machine winding having a winding.

(Prior art) The electrical stress that occurs in the coil insulation built into a generator, etc. is not uniform, and is higher at the corners of the conductor where the electric field is concentrated than at the flat parts of the conductor (for example, in the proceedings of the National Conference of the Institute of Electrical Engineers of Japan, N.
α291. 1986), and since the maximum electric field at this corner becomes larger as the radius of curvature of the conductor corner becomes smaller, in order to alleviate the electric field concentration at the corner, a potential shield layer 1 is used as shown in Fig. 3. A method has been devised in which a semiconductive tape or sheet is wound around the outer periphery of the conductor 2 to increase the uniform radius of curvature of the corners (for example, IEEE T
rans.

PAS, Vol, 102. Na 1, 1984
).

(Problems to be Solved by the Invention) In order to provide the shield layer 1 with a high electric field relaxation effect, it is necessary to electrically connect the shield layer 1 to the conductor 2 and control its potential uniformly. The semiconductive thin film material for forming the shield layer 1 has a relatively high electrical resistance in order to suppress the eddy current loss caused by the magnetic flux crossing the slot to an extremely small value when placed in the slot. things are selected. Therefore, there was a problem in that it was difficult to uniformly control the potential of the shield layer 1 over the entire length of the coil.

Therefore, in order to solve the above-mentioned problems, the present invention aims to provide a rotating electric machine winding that can reliably control the potential without impairing the insulation between the individual wires constituting the conductor. purpose.

[Structure of the invention]

(Means for solving the problem) A conductor formed from a bundle of wires, a shield layer formed by winding a semiconductive tape around the outer periphery of this conductor, and a grounding layer formed around the outer periphery of this shield layer. A rotating electrical machine winding characterized by having insulation. .

(Function) In the rotating electric machine winding according to the present invention, at least one of the wire bundles constituting the conductor is a bare wire without a wire coating, so that the bare wire and the shield layer cover almost the entire length of the shield layer. It becomes possible to have electrical connections across the entire length, and the potential of the shield layer can be controlled almost uniformly even in a long turbine generator coil.

(Example) Hereinafter, an example of a rotating electrical machine winding according to the present invention will be described with reference to FIGS. 1 and 2.

2 is a conductor, and this conductor 2 is made by transposing a strand bundle 3 consisting of one bare strand 3a without strand coating and another strand 3b coated in a slot portion of a rotating electric machine, and converting the strands into strands. A vertical separator 5 is inserted as an insulation between the rows, and a filler 6 is filled in the dislocation portion, which is then molded. The shield layer 1 is made by impregnating a polyester nonwoven tape used as a reinforcing material with a thermosetting resin mixed with carbon black to give it semiconductivity, and a heat-treated semiconducting tape 4 is continuous around the outer periphery of the conductor 2. Roll and form.

Further, a mica tape for ground insulation is wound around the outer periphery according to the rating of the rotating electric machine, and then a thermosetting resin is impregnated and hardened to form the ground insulation 7.

Next, the effect will be explained. In such a configuration, the position of the bare wire 3a in the wire bundle 3 constantly changes in the longitudinal direction of the coil due to dislocation, but the bare wire 3a has a direct electrical connection with the shield layer 1 over its entire length. Since this is possible, the potential of the shield layer 1 can be uniformly controlled over almost the entire length. Also, since there is only one bare wire 3a, the insulation between it and other wires 3b is limited to the covered wire 3b.
ensured by insulation.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but the gist of the invention can be modified by, for example, changing the material of the semiconductive tape 4 or increasing the number of bare wires 3a without wire coating. It can be modified and implemented as long as it does not change. In addition, when employ|adopting several bare strands 3a, each bare strand 3a is arrange|positioned at the position which does not contact each other directly.

〔Effect of the invention〕

As explained above, according to the present invention, at least one bare wire is used in the conductor, and this bare wire is used as the electrical connection part with the shield layer, so that the insulation between each wire is impaired. It is possible to control the potential uniformly over the entire length of the shield layer without any interference.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a rotating electrical machine winding according to the present invention, FIG. 2 is a schematic diagram of a shield layer in an embodiment of a rotating electrical machine winding according to the present invention, and FIG. 3 is a schematic diagram of a conventional rotating electrical machine. It is a sectional view showing a part of slot 1 of winding. DESCRIPTION OF SYMBOLS 1... Shield layer, 2... Conductor, 3... Wire bundle 3a... Bare wire, 3b... Covered wire,
4...Semi-conductive tape 7...Main insulation agent Patent attorney Noriyuki Chika Ken Yudo Daishimaru Ken Figure 1 Figure 3

Claims (1)

[Claims] A conductor formed of a wire bundle consisting of a coated wire with wire insulation and at least one bare wire, and a shield layer formed by winding a semiconductive tape around the outer periphery of the conductor. , and a ground insulation formed on the outer periphery of the shield layer.