JPS5931010A - Induction electric apparatus - Google Patents

Abstract

PURPOSE:To improve insulation capability and cooling property by a construction wherein vertical cooling paths between windings and insulating tubes are closed so that the cooling medium having passed an intermediate oil path formed in the upper winding is made to flow through vertical cooling paths defined by an electrostatic shield and an insulating barrier, and then discharged out of the space above the insulating barrier. CONSTITUTION:An induction electric apparatus has insulating barriers 11a, 11b in the form of plural layers and comprises a plurality of disc winding units 1 each formed by winding strand conductors 2 between inner and outer insulating tubes 3, 4, as well as an electrostatic shield 9 for moderating the electric field. An upper winding unit 1a, 1b of the winding unit 1 is divided to provide an intermediate oil path, and vertical cooling paths 6, 7 between the winding units 1 and the inner and outer insulating tubes 3, 4 are closed by shielding plates 8, 8a, 8b. By so doing, the cooling medium having passed the intermediate oil path flows through vertical cooling paths 12a, 12b defined by the shield 9 and the insulating barriers 11a, 11b, and it is then discharged out of an upper insulating barrier space 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to inductive electrical equipment such as transformers and reactors having a barrier insulation structure.

[Technical background of the invention and its problems]

In recent years, the demand for electricity has increased dramatically, especially in urban areas, and substation equipment has become increasingly high-voltage and large-capacity. but,
This is a social demand as equipment becomes larger due to ultra-high voltage and larger capacity.

The supply of compact, energy-saving equipment is highly desirable. In response to this demand, various attempts have been made and various downsized structures have been proposed for oil-immersed transformers. This is a transformer with a σ barrier lP2 edge structure, which takes advantage of the fact that the breaking stress value of oil is often high by dividing the oil gap into smaller parts with the barrier. but,
In this case, the problem is the distribution of the flow of the cooling medium.

Conventionally, the disk winding of a forced cooling type transformer has a plurality of winding units 1 formed by winding a bare wire conductor 2 between inner or outer insulating tubes 3 and 4, as shown in FIG. are arranged in two sequential order in the axial direction C. Between the winding units 1, horizontal cooling paths (hereinafter referred to as horizontal cooling paths) 5 are partitioned at equal pitches in the circumferential direction by a plurality of horizontal duct pieces (not shown).
A groove 7] is formed between each winding unit 1 and the inner or outer insulation f#f3゜4, and corresponds to the horizontal cooling passage 5 by a plurality of duct pieces (not shown) extending in the axial direction. As a result, axial cooling M (hereinafter referred to as vertical cooling path) 6.7 is formed on the inner side and on the inner side which are divided at equal pitches in the circumferential direction C1. Furthermore, the vertical cooling path 6
7, a closing plate 8 is attached to the inside or outside of C1 for every several winding ratios of 1, and the flow path is zigzag to improve cooling efficiency. In addition, a shield 9 is attached to the end of the winding unit 1 (Second) for mitigating the electric field to prevent dielectric breakdown due to electric field concentration at the end of the first winding. The medium exits outside the winding C1 through a discharge port 10 cut out in the upper part of the external H cylinder 4.However, in various configurations in which another unit winding is wound outside f2 of the winding concerned, Due to the stress 62 of the opening for the cooling medium discharge part 10, the insulation distance between the windings increases.
Become.

That is, when the cooling medium is, for example, transformer insulating oil, the breaking stress of the oil gap is expressed as E=K·g (K is a constant and the oil gap length). Therefore, the larger the length of the opening, the lower the destructive stress, so the total insulation distance must be 7 hours. like this(
-1 Increased Capacity of Equipment and Ultra-High Pressure f- With the trend towards larger equipment, increasing the size of equipment is no longer a ritual, and due to various constraints such as transportation restrictions, it is desired to provide equipment that is as small and compact as possible. Considering the distribution of the flow of the cooling medium, it is desirable to secure a cooling path and a discharge opening for the cooling medium without impairing the cooling performance, and to have a woven structure with strong electrical insulation.

[Purpose of the invention]

In this respect, the present invention secures a discharge opening for cooling, improves cooling performance, has excellent insulation properties, is highly reliable, is compact, and increases special work processes. The purpose of the present invention is to provide a transformer that can be manufactured easily and inexpensively without any problems.

[Summary of the invention]

In order to achieve the above objects, the present invention has a C1 cypress layer insulation barrier, and a disk winding unit and a winding unit formed by winding a cable conductor between an inner insulating cylinder and an outer insulating cylinder. In an induction electric device comprising an electrostatic shield for mitigating an electric field at an end, an upper winding unit of the winding unit is divided to provide an intermediate oil passage,
By blocking the vertical cooling path between the winding unit and the inner and outer insulating tubes with a blocking plate, an insulating barrier is provided that protects the cooling medium that has passed through the intermediate oil path between the electrostatic ring and the inside and outside of the end of the fifth winding. The feature is that the oil flows through the vertical cooling channels created and drains from the upper insulating barrier space.

[Embodiments of the invention]

Hereinafter, the present invention will be explained using two embodiments shown in Fig. 2C. 1 Clothes Doto t:I
: 2 winding units] a, 1 bl It is formed by winding a wire conductor 1 body 2 so as to divide it into two parts. The divided winding units 1a, lb are surrounded by inner or outer insulating tubes 3, 4 via a plurality of inner or outer vertical duct pieces (not shown). Further, between the inner and outer axial cooling passages (vertical cooling passages) 6.7 of the 512 winding units 1a and lb and the inner or outer insulating cylinder 3.4, there is a flow from the closing plates 8a and 8b l-. road is blocked. Furthermore, there is a gap between the shield 9, which is placed at the end f2 of the winding unit 1, and the L-shaped barriers lla and llb, which protect the inside and outside of the winding end. (Two vertical cooling channels 12a and 12b are formed 1, and the space 13 between the L-shaped barriers 11a and 11b is used as a cooling medium discharge port.

In the transformer winding formed as described above, the cooling medium flowing inside the winding flows in a zigzag pattern through the blocking plates 812 provided at various locations, and cools the winding unit 1.

On the other hand, in the upper divided winding units 1a and lb, the closing plate 8a
, 8b are blocking the vertical cooling passages 6.7, the insulating medium follows the intermediate oil passages of the divided winding units 1a and lb, and is divided at the lower surface of the shield 9, forming the shield 9 and the inner wall type barrier lla. The liquid flows through the cooling path 12a and the cooling path 12b formed by the shield 9 and the outer outer barrier 11b, merges at the upper part of the shield, and is discharged from the space 13 formed by the inner and outer barriers.

By configuring as described above, an opening for the oil passage is not created at the end of the upper winding unit 1, so the insulation distance between the windings is reduced by the vertical cooling passage or between the Since it can be determined from the roadway, it can be much smaller than when there is an opening between the windings.On the other hand, the cooling medium is now discharged from the space 13 created by the L-shaped barriers lla and Jlb at the top of the shield. , looking at the electric field distribution on the table ifi of the shield 9, the electric field value at the upper part of the shield compared to the curvature s becomes a value that is very small. In addition, according to the present invention, since an intermediate road is provided in the upper winding units 1a, 1b, this % wire unit 1a, 1bl
Although the space factor decreases at -, it is more than compensated for by the improvement in space factor due to the reduction in the insulation distance C2 between the windings. L
7. Compared to the temperature at the bottom of the winding, the temperature at the top of the winding is several dθg in the case of the forced cooling method, and 10 to 20 g in the case of the automatic self-cooling method.
There is a temperature difference of deg. In the configuration of the present invention, the flow is shunted to the horizontal cooling path in the lower winding, but the upper winding units 1a and 1b, which are hotter than other windings, are cooled by the entire flow, so the cooling performance is improved. Significantly improved. Therefore, the cooling efficiency of the entire system is greatly improved, the vertical cooling path 6.7 can be made smaller, and the fracture stress value will be high according to the oil gap fracture stress formula shown earlier, so the overall system dimension In this way, when the line end is placed at the top, the upper line end winding of the high capacity winding is subjected to severe stress on the P edge and also from the point of view of temperature rise. The cooling characteristics and insulation performance are also improved compared to the conventional configuration.

A further advantage of the present invention is that it is possible to omit the labor-intensive process of cutting out the external insulating cylinder 4 in order to provide a cooling medium discharge port, as shown in the conventional example.

〔Effect of the invention〕

As explained above, according to the present invention, an intermediate passage is provided in the upper winding unit, and the winding unit is separated from the winding unit. The vertical cooling path with the 7 cylinders is closed, and the cooling medium that has passed through the intermediate path is allowed to flow through the vertical cooling path created by the electrostatic ring and the insulating barrier that protects the ends of the windings, and is discharged from the space above the insulating barrier. As a result, the vertical path between the first and adjacent windings can be narrowed, and the insulation performance is improved (2. The cooling characteristics of the upper part of the winding where the temperature rise is the largest is improved,
It also has the effect of reducing the number of man-hours required for cutting out the insulating tube.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an example of a disk winding in a conventional transformer C, and FIG. 2 is a schematic cross-sectional view of a transformer winding according to an embodiment of the present invention. Wire unit 1a, lb... Divided winding unit 2... Element wire conductor 3... Inner insulating tube 4...
・Outer insulation cylinder 6.7...Vertical cooling path 8, 8a,
sb... Closing plate 9... Electrostatic shield 11a, l
lb...Insulating barrier 12a, 12b...Vertical cooling path 13...Upper insulating barrier space (7317) Agent Patent attorney Kensuke Chika (and 1 other person) Figure 1 1 ＼ 70 2/3 2 ==]4 B ===]

Claims (1)

[Claims] An induction device that has multiple layers of insulation barriers and consists of a disc winding unit formed by winding a strain conductor between an inner insulating cylinder and an outer insulating cylinder, and an electrostatic shield for mitigating the electric field at the end of the winding unit. In electrical equipment, the upper winding unit of the winding unit is divided to provide an intermediate oil passage, and the vertical cooling passage between the winding unit and the inner and outer insulating cylinders is blocked by the closing plate 62, thereby creating an intermediate oil passage. An induction electric device characterized in that the cooling medium that has passed through is caused to flow through a vertical cooling path created by the electrostatic ring and an insulating barrier that protects the inside and outside of the winding ends, and oil is discharged from the upper insulating barrier space.