JPS61224302A - Stationary induction electric apparatus - Google Patents

Abstract

PURPOSE:To stop the progress of the electric discharge on the impulse part generated by the minute oil gap located between coils and an intercoil spacer by a method wherein the width of a vertical duct is made wider than the width of the intercoil spacer. CONSTITUTION:A vertical groove 5, having the base larger than the aperture part, is formed by a vertical duct piece 2. A protrusion is provided on an interlayer spacer 3 in such a manner that the spacer is fitted in the vertical groove 5 and that the spacer is moved vertical duct piece 2 is constituted in such a manner that it is made wider than the width WS of the intercoil spacer 3. Partial electric discharge is generated from the wedge-shaped microscopic oil gap located between the spacer 3 and the innermost coil of a disc coil, and said electric discharge progresses on the creeping surface of the spacer 3 toward the inner side. However, as the width WV of the duct piece 2 is wider than the width WS of the spacer 3, the progress of the electric discharge is stopped on the surface of the vertical duct. Through these procedures, the dielectric strength between the main insulating members can be improved.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a restoration structure of an oil-immersed transformer, etc., and particularly to a method for forming a draw between coils and between main insulation composed of one disc winding. Regarding duct piece.

[Background of the invention]

Between the coils of the transformer disk winding, inter-coil spacers are arranged at predetermined intervals in the circumferential direction to provide a cooling draw, and the oil gap is selected to a size that prevents dielectric breakdown. Also,
In order to prevent the spacer from shifting to the left or right, the spacer between the coils is fitted to the insulating cylinder placed inside the disk winding and the duct piece between the windings, and the top and bottom of the winding can only be tightened at the top and bottom. It allows you to move to. Specific examples of these are Utility Model Act 57-137
77, as shown in Japanese Patent Publication No. 56-34084, the width of the inter-coil spacer is made larger than the width of the vertical duct piece, so that the notch part of the inter-coil spacer engages with the convex part of the vertical duct piece. Fixed.

This publication does not recognize the problem that the dielectric strength in this configuration is extremely low because the path of partial discharge reaching the side surface of the vertical duct piece via the creeping surface of the inter-coil spacer is short.

[Purpose of the invention]

The object of the present invention is to provide a stationary induction electric appliance that improves the creeping voltage of an insulating cylinder.

[Summary of the invention]

In the present invention, in order to lengthen the creeping discharge path between the coil surface and the insulating tube when the disc winding is composed of an insulating tube, a vertical duct piece, and an inter-coil spacer, the width of the vertical duct is made larger than the width of the inter-coil spacer. It was designed to be larger.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to FIGS. 1, 2, and 3. Figure 1 is a plan view showing the partial structure of the insulation, tube 1, vertical duct piece 2, and inter-coil spacer 3 in a disc winding. is formed. The inter-coil spacer 3 is provided with a convex portion to fit into the vertical groove 5, and has a vertical i
It is possible to move up and down along line 15. Further, the width Wv of the vertical duct piece 2 is configured to be larger than the width WS of the inter-coil spacer 3.

FIG. 2 shows a part of the disk winding wire constructed along the plane number 1--2 in FIG. Insulating cylinder 1. It is composed of a vertical duct piece 2, a plurality of inter-coil spacers 3 fitted in vertical grooves 5, and a disc coil 4.

When the disc coil 4 is wound and the drying process and upper and lower tightening operations are performed, the spacer 3 between the coils can be slid upward and downward along the vertical groove 5.

It is well known that it is extremely important for transformer windings to be insulated against lightning impulse voltage in addition to insulation against AC voltage. Voltage is generated. In addition, a large voltage is generated also in other windings arranged concentrically on the inside, so that it is required to have sufficient dielectric strength against the so-called main insulation in the radial direction. In this way, it receives electric fields both between the coils in the axial direction and between the main insulation in the radial direction,
When the width Wv of the vertical duct piece 2 is smaller than the width of the inter-coil spacer 3, the partial discharge occurs like a wedge-shaped micro-discharge formed between the inter-coil spacer 3 and the innermost coil of the disc coil 4.
Since the width is larger than the width WS, the progress is blocked in that respect.

Further, since the inter-coil spacer 3 protrudes into the vertical groove 5, the partial discharge also develops into the vertical groove, and the electric field on the side surface of the vertical duct piece is further relaxed by the progress of the partial discharge.

Therefore, destruction of the side surface of the vertical duct piece, which tends to develop into the insulating tube 1, is less likely to occur, and the dielectric strength can be improved. FIG. 3 is an example of experimentally examining the effect of the present invention. When the width Wv of the vertical duct piece is made larger than the width WS of the inter-coil spacer as in the present invention, a If the applied voltage is high until the magnitude of discharge reaches a harmful level and Wv is smaller than WS, the harmful level is reached at a low applied voltage as in characteristic B. In other words, the partial discharge that has developed from the corner of the coil along the creeping surface of the inter-coil spacer □ is prevented from progressing on the vertical duct surface, and does not become a large partial discharge. Figure 4 shows another embodiment of the invention.

The vertical groove 15 of the vertical duct piece 11 is narrowed only at the opening part. Even with this shape, the vertical duct 11
Since the width Wv of can be made larger than the width WS of the inter-coil spacer 12, it is possible to prevent the progress of partial discharge, and it has the same effect as the shape shown in FIG. 1, making it easier to manufacture the vertical duct piece 11. It has the advantage of being

FIG. 5 shows still another embodiment of the present invention, in which a protrusion 23 is provided at the portion where the vertical duct piece 21 and the inter-coil spacer 22 are in contact. Even in this structure, the width W of the protrusion 23 of the vertical duct piece 21 is larger than the width WS of the inter-coil spacer 22, so it is possible to prevent the progress of partial discharge. It can be molded by bonding two insulators together.

〔Effect of the invention〕

According to the present invention, it is possible to prevent the progress of impulse partial discharge generated in the minute oil gap between the coil and the spacer between the coils on the vertical duct surface, improve the dielectric strength between the main insulation, and achieve high dielectric strength. It can be a transformer winding.

[Brief explanation of the drawing]

FIG. 1 is a plan view of one embodiment of the present invention, FIG. 2 is a side sectional view of the present invention, FIG. 3 is a characteristic diagram comparing the effects of the present invention, and FIG. 4 is another embodiment of the present invention. FIG. 5 is a plan view of still another embodiment of the present invention. 1... Insulating tube, 2... Vertical duct piece, 3...
Spacer between coils, 4... Disc coil, 5... Vertical groove. Fu Hataya 4 (18 ￥ S Mouth)

Claims (1)

[Claims] 1. An insulating cylinder and a disc winding are arranged in a circular manner on the core leg, and vertical oil is supplied between the first insulating cylinder and the disc winding through a plurality of vertical duct pieces. A transformer winding configured by forming a horizontal oil passage between a plurality of disc coils via an inter-coil spacer, and fitting the inter-coil spacer to the vertical duct piece, A stationary induction electric appliance characterized in that the width of the duct piece is made larger than the width of the inter-coil spacer, and the inter-coil spacer is fitted to the vertical duct piece. 2. A stationary induction electric appliance according to claim 1, characterized in that a vertical groove is provided in the vertical duct piece on the surface in contact with the disc winding. 3. A stationary induction electric appliance according to claim 1, characterized in that a protrusion larger than the width of the inter-coil spacer is provided on a side surface of the vertical duct piece forming the vertical oilway.