JP2013065762A - Stationary induction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable stationary induction apparatus in which a cooling oil gap formed in the shield part at the end-of-winding is ensured while enhancing the insulation performance.SOLUTION: The stationary induction apparatus through which insulation oil circulates includes a plurality of cylindrical windings 1, 2 wound around an iron core, electrostatic shields 6, 7 attached to the ends of windings, and an insulation barrier 5 for dividing the oil gap attached to the outside of the electrostatic shields 6, 7. The electrostatic shield 6 is divided so that the opening of the divided portion serves as the flow path 6a of the insulation oil. Planar insulation barriers 10, 11 having an opening are attached so as to straddle the electrostatic shield 6 thus divided and the insulation barrier 5 for dividing the oil gap attached to the outside of the shield. The insulation oil is made to flow through openings 12, 13 provided, respectively, in the electrostatic shields 6, 6 thus divided and the planar insulation barriers 10, 11.

Description

  Embodiments described herein relate generally to an oil-filled stationary induction device such as a transformer and a reactor.

  Currently, oil-containing stationary induction devices such as transformers and reactors are increasing in voltage and capacity, and their dimensions tend to increase. On the other hand, regarding the location of substations and power plants where static induction equipment is installed, the installation space for underground substations in urban areas tends to be reduced in consideration of environmental conditions, and when installing in mountainous areas, etc. There are restrictions on transportation by rail and road. Under such circumstances, the static induction device is required to be reduced in size by reducing the insulation dimension required by the internal winding.

  Conventional ultra-high-pressure oil-filled static induction equipment forms a plurality of insulation barriers between windings or between windings and iron core, and creates oil gaps (insulating oil generated between windings or between windings and iron core). Insulation methods are used to increase the withstand voltage between the windings by subdividing the gaps (also referred to as gaps or flow paths). This insulation method is usually called barrier insulation.

  Specifically, in the static induction device employing this barrier insulation, a plurality of insulation barriers are concentrically mounted between the windings to subdivide the oil gap between the windings. Also, a plurality of plate-like insulation barriers are mounted between the winding and the yoke core, or an L-shaped barrier (generally called an oil gap dividing barrier) is provided outside the electrostatic shield provided on the winding. The oil gap around the winding is subdivided.

As described above, the oil gap is subdivided by the insulating barrier. If the dimension of the oil gap is d and the breakdown electric field is E, there is a relationship of E = kd- ^a. This utilizes the property that the breakdown electric field becomes high. This property is described in Non-Patent Document 1, for example.

IEEJ Discharge Handbook Publishing Committee: “Discharge Handbook Vol. 2” (issued in 1998)

JP 2000-106311 A

  The oil-containing stationary induction device is filled with insulating oil for cooling and insulating the winding, and the insulating oil is circulated by an oil pump provided outside the transformer tank. For example, the insulating oil introduced to the lower side of the high-voltage winding is used between the winding sections, between the winding and the oil gap subdivided by the insulation barrier, and between the electrostatic shield and the L-shaped oil gap dividing barrier. It is supposed to flow through.

  On the other hand, when a voltage is applied to the high voltage winding, the electric field concentrates on the end of the electrostatic shield attached to the end of the winding. In particular, this tendency is strong in recent ultra-high voltage and ultra-high voltage static induction equipment exceeding 500 kV.

  Since the electric field concentrates at the corners of the electrostatic shield, an L-shaped oil gap dividing barrier is placed closer to the electrostatic shield at the outer periphery of the part than between the insulation barrier and the winding. Need to be shortened. However, if the oil gap is shortened, the insulating oil cannot effectively flow between the L-shaped oil gap dividing barrier and the electrostatic shield, which causes a cooling problem.

  An object of an embodiment of the present invention is to provide a reliable static induction device capable of improving insulation performance while ensuring a cooling oil gap formed in a shield part at a winding end. It is in.

The embodiment of the present invention is characterized by adopting the following means in order to solve the above-mentioned problems.
(1) Inside a static induction device through which insulating oil circulates, a plurality of cylindrical windings wound around an iron core, an electrostatic shield attached to a winding end of the winding, and the electrostatic shield An insulating barrier for oil gap division attached to the outside is provided.
(2) The electrostatic shield is divided, and an opening is formed in the divided portion.
(3) A plate-shaped insulating barrier having an opening is attached so as to straddle the divided electrostatic shield and the oil gap dividing barrier attached to the outside of the shield.
(4) Insulating oil is allowed to flow through openings provided in each of the divided electrostatic shield and the plate-like insulating barrier.

The internal sectional view of the transformer concerning the embodiment of the present invention. The top view of the plate-shaped insulation barrier used for embodiment of this invention. Sectional drawing of the plate-shaped insulation barrier used for embodiment of this invention.

  A first embodiment of the present invention will be described with reference to FIGS.

[1-1. Constitution]
In FIG. 1, 1 is a high-voltage winding, 2 is a low-voltage winding, and a low-voltage winding 2 and a high-voltage winding 1 are concentrically disposed on a main leg iron core (not shown). A plurality of insulating cylinders 4 are concentrically mounted between the high voltage winding 1 and the low voltage winding 2 and between the high voltage winding 1 and a tank (not shown). In the present embodiment, one insulating cylinder 4 is provided on the outer peripheral side of the low voltage winding 2, an inner / outer double insulating cylinder 4 is provided on the inner peripheral side of the high voltage winding 1, and two inner and outer sides are provided on the outer peripheral side of the high voltage winding 1. A heavy insulating cylinder 4 is provided.

  Electrostatic shields 6 and 7 are attached to the high-voltage winding 1 and the low-voltage winding 2 on the yoke core 3 side, respectively, so as to reduce the electric field at the ends of the high-voltage winding 1 and the low-voltage winding 2. The electrostatic shield 6 on the high-voltage winding 1 side is divided into two in the radial direction, and a gap 6 a serving as an insulating oil flow path is provided between the inner and outer electrostatic shields 6 and 6. The electrostatic shield 7 of the low voltage winding 2 is arranged so as to face the end of the low voltage winding 2 without being divided.

  An L-shaped oil gap dividing barrier 5 is attached to each of the plurality of concentric insulating cylinders 4 so as to cover the electrostatic shields 6 and 7. That is, the lower part of the vertical part of the oil gap dividing barrier 5 is fixed to the upper part of the concentric insulating cylinder 4. Further, the upper part of the oil gap dividing barrier 5 is bent and extends to above the winding end, and the horizontal part (part parallel to the yoke core 3) and the vertical part (the part parallel to the yoke core 3) of the electrostatic shields 6 and 7 are provided. The portion along the stacking direction of the windings) is covered. In this embodiment, since the concentric insulating cylinders 4 are doubly provided on the inner peripheral side and the outer peripheral side of the high-voltage winding 1 as described above, the L-shaped oil gap dividing barrier 5 is also static The electric shield 6 is doubled on the inner and outer sides of the electric shield 6.

  Provided in the horizontal part (part parallel to the yoke core 3) of the oil gap dividing barrier 5 provided in the insulating cylinder 4 on the outer peripheral side of the high-voltage winding 1 and in the insulating cylinder 4 on the inner peripheral side of the high-voltage winding 1 The horizontal portion of the oil gap dividing barrier 5 is arranged in parallel with the horizontal portion of the electrostatic shield 6 with a gap serving as an insulating oil flow path with respect to the surface of the electrostatic shield 6. Further, a gap is formed between the tip portions of the horizontal portions, and this gap serves as an insulating oil flow path 5a.

  In addition, 8 is an oil stopper which prevents oil from flowing to an unnecessary part, and is an insulator bonded to the L-shaped oil gap dividing barrier 5.

  A plate-like insulating barrier 10 is attached to the surface of the electrostatic shields 6 and 6 so as to straddle the flow path 6a of the two divided electrostatic shields 6 and 6. Similarly, a plate-like insulating barrier 11 is attached so as to straddle the flow path 5 a provided at the tip of the horizontal portion of the L-shaped oil gap dividing barrier 5.

  Examples of the shape of these plate-like insulating barriers 10 and 11 are shown in FIGS. As shown in the drawing, the plate-like insulating barriers 10 and 11 have a plurality of slit-shaped rectangular openings 12 having long sides in the circumferential direction of the winding, or circular shapes arranged along the circumferential direction of the winding. The opening 13 is provided. When the plate-like insulating barriers 10 and 11 are stacked, the openings 12 and 13 are provided at positions where the positions do not overlap, for example, as shown in FIG. In the present embodiment, these openings 12 and 13 form an insulating oil flow path.

[1-2. Action]
In the present embodiment having such a configuration, the insulating oil flowing in the winding is in the flow path 6a formed in the divided portion of the electrostatic shields 6 and 6 attached to the end of the high voltage winding 1. Flow into. After that, the plate-shaped insulating barriers 10 and 11 attached to the electrostatic shields 6 and 6 and the flow path 5a of the L-shaped oil gap dividing barrier 5 through the flow path 6a between the electrostatic shields 6 and 6. The slit-shaped rectangular opening 12 or the circular opening 13 is discharged outside the winding.

  The electric field at the end of the high voltage winding 1 is alleviated by the divided electrostatic shields 6 and 6 and the oil gap dividing barrier 5 provided around the electrostatic shields 6 and 6. In particular, in this embodiment, since the L-shaped oil gap dividing barrier 5 is provided outside the electrostatic shields 6 and 6, the dimension d of the oil gap can be shortened, and the breakdown electric field is high. Become.

[1-3. effect]
The effects of the present embodiment having the above-described configuration and operation are as follows.

(1) Since the electrostatic shield 6 is divided into two in the radial direction and an insulating oil flow path 6a is formed between them, the L-shaped oil gap dividing barrier 5 is brought close to the end of the electrostatic shield 6. Even if attached, the insulating oil can be discharged from the winding 6a to the outside of the winding. This makes it possible to attach the L-shaped oil gap dividing barrier 5 in the vicinity without impeding the flow of the insulating oil, thereby improving the cooling performance.

  That is, if the flow of the insulating oil is hindered, the cooling performance of the stationary induction device is lowered, the winding temperature is increased, and eventually an accident may occur. However, in this embodiment, since the insulating oil flows smoothly, it is possible to provide a stationary induction device with improved withstand voltage and high insulation reliability.

(2) The plate-shaped insulating barriers 10 and 11 are provided with slit-shaped rectangular openings 12 or circular openings 13, and the flow rate of the insulating oil is changed by changing the size of the openings. Since the flow rate can be controlled, the winding can be cooled to an appropriate temperature.

(3) When the plurality of insulating barriers 10 and 11 are arranged, the positions of the rectangular opening 12 or the circular opening 13 do not overlap with each other. The value of the oil gap d at E = kd− ^a can be reduced to improve the withstand voltage characteristics.

[2. Other Embodiments]
The present invention is not limited to the above-described embodiment, and includes other embodiments as follows.

(1) The shape and position of the opening are not limited to those shown in FIGS. You may form an opening part by notching the side part of the insulation barriers 10 and 11. FIG.
(2) The electrostatic shield can be further divided into a large number in addition to being divided into two in the radial direction.

(3) It is also possible to use another insulating fluid instead of the insulating oil.

(4) Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... High voltage winding 2 ... Low voltage winding 3 ... Yoke iron core 4 ... Insulation barrier 5 ... L-shaped oil gap division | segmentation barriers 6, 7 ... Electrostatic shield 8 ... Oil retaining 10, 11 ... Plate-shaped insulation barrier 12, 13 ... Opening

Claims (4)

Inside the static induction device through which the insulating fluid circulates, a plurality of cylindrical windings wound around an iron core, an electrostatic shield attached to the winding end of the winding, and a horizontal portion of the electrostatic shield, An insulating barrier for dividing an L-shaped oil gap having a horizontal part and a vertical part covering the vertical part,
The electrostatic shield is divided, and the opening of the divided portion is used as a flow path for the insulating fluid,
A plate-like insulating barrier with an opening is attached so as to straddle the divided electrostatic shield,
A static induction device characterized in that an insulating fluid is caused to flow from a flow path of a divided portion of the electrostatic shield through an opening provided in a plate-like insulating barrier. The L-shaped oil gap dividing barriers are respectively provided on the inner and outer peripheral sides of the winding so as to cover the electrostatic shield,
A gap is provided between the tips of the horizontal portions of the L-shaped oil gap dividing barriers on the inner peripheral side and the outer peripheral side, and this gap is used as a flow path for the insulating fluid.
A plurality of plate-like insulating barriers are attached so as to straddle the horizontal part of the L-shaped oil gap dividing barrier on the inner peripheral side and outer peripheral side,
2. The stationary induction device according to claim 1, wherein an opening is provided in the plate-shaped insulating barrier, and the opening serves as a flow path for an insulating fluid.   The opening of the plate-like insulating barrier is a rectangular slit having a long side in the circumferential direction of the winding, or a plurality of circular holes arranged in the circumferential direction of the winding. The stationary induction device according to claim 1 or claim 2. The plate-like insulation barrier is provided in plural at the winding end, and the position of the opening provided in each insulation barrier does not overlap. Stationary induction equipment.

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