JPH09247812A - Main circuit disconnector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a main circuit disconnector which increases a cooling efficiency and suppresses the rise in temperature of a contact section including a central conductor. SOLUTION: A central conductor 10 is connected to a breaker-side central conductor 14 through a contactor 15. An insulating layer 11 is formed around the central conductors and is fastened to a flange 12 by the outermost layer 11a. On the other hand, in a part of the insulating layer 11 neat the contactor 15, opening holes 16 are so perforated that the ratio h/W of the height h from the flange 12 to a distance w in a straight line between the flange 12 and the central conductor 14 may be unity or above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a main circuit disconnecting device.

[0002]

2. Description of the Related Art In a general switchgear, a main circuit disconnecting device plays an important role in a panel structure provided for connecting a movable electric device such as a circuit breaker to a load busbar arranged in a busbar room. There is.

In FIG. 9 showing an example of the structure of a switchgear, a breaker 2 is housed in the box body 1 on the front side, and a bus bar connecting the cable head 3, the current transformer 4 and the board is installed in a bus room on the back side. 5 is stored. Further, a partition plate 6 is provided between the circuit breaker 2 and the busbar chamber side, and the main circuit disconnecting portions 7a and 7b correspond to the main circuit conductors of the circuit breaker 2 in through holes (not shown) of the partition plate 6. Each is installed. A shutter 8 protects the charging parts of the main circuit breaker parts 7a and 7b when the breaker 2 is disconnected. Moreover, 9 is a connection conductor, and the respective electric devices are connected to each other.

Since the circuit breaker 2 sides of the main circuit breaker sections 7a and 7b have the same structure, the structure of the main circuit breaker section will be described taking the bus bar side having a linear shape as an example. FIG. 10 shows a sectional view. An insulating layer 11 is formed around the center conductor 10 by molding, and an outermost peripheral layer 11a protruding substantially in the center is fixed to a mounting flange 12 by a bolt 13.

Further, a contactor 15 is attached to the circuit breaker-side center conductor 14, and by moving these, it is connected to the center conductor 10 on the main circuit disconnecting section side. In addition, contact
The outer diameter of the central conductor 10 exposed in the air portion connected to 15 is a portion 10a slightly smaller than the outer diameter in the insulating layer, so that electric field relaxation is achieved.

Further, the insulating layer 11 on the side of the circuit breaker 2 has a tubular shape 11b, and the central conductors 10 and 14 and the flange 12 which penetrate the tubular layer 11b.
It has a barrier effect between them. Further, between the main circuit (not shown) on the circuit breaker 2 side and the flange 12, the tip 11 of the tubular portion 11b is
c acts as a barrier effect.

[0007]

In these structures, a barrier effect is exerted between the central conductors 10 and 14 and the flange 12 by the insulating layer 11 of the cylindrical shape 11b, and the electric field of the contact 15 is relaxed, which is favorable. Insulation performance is maintained. This is the real public sho 59
-36093.

However, considering the thermal characteristics,
Contact 15 for connecting the central conductor 10 and the circuit breaker central conductor 14
Since the contact 15 has contact resistance, the temperature rise due to Joule heat during energization is remarkable.

Since the contactor 15 is located in the insulating layer 11 of the cylindrical shape 11b, and the resin insulator generally used as the insulating layer 11 has low thermal conductivity, it is mainly used for the above temperature rise. Cooling by convection. But tubular 11
Since the air flow path is narrow in the insulating layer 11 of b, the ventilation efficiency is poor and heat is trapped, which promotes the temperature rise in the vicinity of the contactor 15.

In order to suppress such a temperature rise, the number of fingers is increased so as to increase the diameter of the central conductor 10 and the breaker side central conductor 14 or increase the contact points of the contact 15 in order to reduce the contact resistance. It is possible to increase. However, the coaxial direction of the main circuit disconnecting device becomes large and the diameter becomes large. This goes against the recent trend toward smaller and lighter devices. An object of the present invention is to provide a main circuit disconnecting device capable of preventing a temperature rise in the insulating layer including the vicinity of the contact.

[0011]

In order to achieve the above object, the invention according to claim 1 has a central conductor whose one end can be connected to a movable electric device, and a cylindrical insulating layer formed around the central conductor. And an opening hole provided in the insulating layer and a flange to which the insulating layer is fixed, and a distance h between the position where the opening hole is provided and the flange, and a distance W between the center conductor and the ground flange. The summary is that the ratio h / W of 1 is 1 or more.

In such a structure, the cylindrical insulating layer covering the central conductor is provided with the upper and lower openings for heat dissipation, so that ventilation can be performed and the temperature rise can be suppressed. Further, since this opening has a height h equal to or greater than the linear distance (insulation distance) W between the center conductor and the ground flange, the withstand voltage characteristic is not significantly deteriorated.

According to a second aspect of the present invention, a plurality of cylindrical insulating layers are formed, the outermost insulating layer is fixed to the flange, and the opening holes of the insulating layer closest to the center conductor are provided above and below. The gist is that the insulating layer after that is provided with opening holes by changing the angle by 90 °.

In such a structure, since a plurality of cylindrical insulating layers are used, the barrier effect is greatly exerted and the withstand voltage characteristic can be improved. In this case, the cylindrical insulating layer on the side of the central conductor is made highest so as to have a barrier effect with the side of the circuit breaker. Then, since the circuit breaker side has a complicated electrode shape such as a bolt for fixing the central conductor, a barrier can be provided at a position closest to the central conductor to maximize the withstand voltage improving effect.

Further, according to the invention of claim 5, a center conductor having one end connectable to a movable electric device, a cylindrical insulating layer formed around the center conductor, and a flange to which the insulating layer is fixed are provided. The gist is that the central conductor side of the insulating layer is inclined, and the inclination angle formed with the central conductor is 20 ° to 25 °.

In such a structure, the inflow of air becomes smooth due to the inclination of expanding the central conductor side of the insulating layer toward the breaker side. Furthermore, the inclination angle cannot be expanded indefinitely because the size of the insulating layer must be minimized and the insulation distance must be secured.Therefore, it is possible to predict the relationship between the inclination angle and the conductor surface temperature of the main circuit disconnection part from a certain angle. It was judged that no temperature drop would occur, and the inclination angle was set to 20 to 25 degrees as the most effective cooling effect.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the main circuit disconnecting device of the present invention will be described below with reference to the drawings. The same parts as those in the prior art are designated by the same reference numerals and the description thereof will be omitted. FIG.
It is sectional drawing of the main circuit disconnection apparatus which shows the 1st Example of this invention. In the figure, an insulating layer 11 is formed around the center conductor 10, and the protrusion 11a at the substantially central portion is formed on the flange 12a.
It is fixed by bolt 13 to. A contactor 15 is provided on the center conductor 14 on the circuit breaker side and is connected to the center conductor 10 on the main circuit disconnection section side. A cylindrical insulating layer 11b is formed on the outer periphery of the central conductor 14, and has the same structure as the conventional one.

The cylindrical insulating layer 11b has an opening hole 16 for heat dissipation.
Are provided in the vertical direction. The position of this opening 16 is
The height h of the flange 12 and the opening hole 16 is equal to or greater than the linear distance W between the center conductor 14 and the flange 12.

FIG. 2 shows an example of this positional relationship and withstand voltage characteristics. Characteristic (a) is the withstand voltage characteristic of the opening hole 16, and h /
The withstand voltage increases as the ratio of W increases, but h
When / W becomes 1 or more, it tends to be saturated. Looking at the breakdown path, when h / W is 1 or less, it is discharge in the air gap depending on the tension distance, but when h / W is 1 or more, it creeps along the surface of the cylindrical insulating layer 11b. This is because it will be discharged. In other words, in the air gap discharge, the withstand voltage characteristic is almost proportional to the tension yarn distance, but in the creeping discharge, the characteristic is substantially saturated due to the influence of the specific capacitance of the insulating layer.

The characteristic (b) is the characteristic between the central conductor 14 and the flange 12 when the cylindrical insulating layer 11b is not provided. Here, the tubular insulating layer tip 11c acts as a barrier effect between the flange 12 and a portion where the electric field strength is severe, such as the center conductor 14 on the side of the circuit breaker 2 or a fixing bolt (not shown).

In such a structure, the vicinity of the contact 15 that produces the largest amount of heat can be ventilated by the opening 16 to suppress the temperature rise. The opening holes 16 are provided on the upper and lower sides, and are about 1% of the surface area of the insulating layer 11b, but the upper side area is larger than the lower side area. Thereby, the temperature rise can be further suppressed. this is,
This is because the air flow is improved, and the horizontally arranged cylindrical insulating layer 11b is effective.

In this case, since the opening hole 16 has h / W of 1 or more, the withstanding voltage characteristic can be maintained satisfactorily without lowering. Next, FIG. 3 shows a configuration in which a second insulating layer 11d is provided on the outer periphery of the cylindrical insulating layer 11b. Here, when the height of the second insulating layer 11d is large, the opening hole 17 has an h / W ratio of 1 or more as in the above. Further, the opening holes 17 are located on the left and right. That is, as shown in FIG. 4, the second insulating layer 11b is provided with the second hole 16 in the second insulating layer 11b.
The opening holes 17 of the insulating layer 11d are shifted by 90 degrees. As a result, between the center conductor 14 and the flange 12, two insulating layers 11
Since b and 11d are provided, the withstand voltage characteristic is further improved. The characteristic (c) of FIG. 2 shows the characteristics of the two sheets, but the withstand voltage characteristics are improved as compared with the case of one sheet. This is because the first and second insulating layers 11b-11d have an equal electric field.

If there is a space for providing an insulating layer between the central conductor 14 and the flange 12, it is possible to improve the withstand voltage by adding a plurality of sheets. As a result, it is possible to reduce the size of the main circuit disconnection portion in the coaxial direction. Also,
Since the temperature rise can be suppressed by the opening holes 16 and 17, the capacity can be increased.

Here, the tip 11c of the first insulating layer is made longer than the second and subsequent insulating layers and has the longest shape in order to act a barrier effect with the circuit breaker 2 side not shown. That is, it is a structure in which an insulating layer having a large effect is arranged at a position closest to the electrode.

In addition, such a main circuit disconnecting portion is apt to suppress the temperature increase of the contact portion, even if the temperature is relatively increased such as a vacuum circuit breaker. this is,
If the temperature rise is small in areas other than the contact area, the temperature of the contact area will be pulled to the lower side, whereas in the case of a circuit breaker that raises the temperature to the same extent, it is difficult to move the temperature.
This is because the effects of 6 and 17 are large.

As another embodiment, even in an electric device in which flat plate-shaped barriers are arranged in the vertical direction between electrodes, by providing an opening hole for heat dissipation at a position equal to or more than the distance between electrodes, the temperature rise can be achieved. An insulating structure of an electric device that suppresses and maintains good withstand voltage characteristics can be obtained.

FIG. 5 is a sectional view of a main circuit disconnecting device showing a third embodiment of the present invention. In the figure, the resin insulating layer 11 of the main circuit disconnecting device protruding toward the circuit breaker is molded with an inner side surface inclined. This inclination is set within a range in which the tip of the insulating layer 11 maintains an insulating distance from the circuit breaker center conductor 14.

Then, the inclined surface of the insulating layer 11 allows the low-temperature air to smoothly flow in from the lower end of the circuit breaker-side open end. Further, the high-temperature air heated in the deep portion of the insulating layer 11 is guided to the inclined insulating layer 11 and quickly flows out to the outside. As described above, by providing the insulating layer 11 with the inclination to set the flow path of the air and promote the ventilation by the natural convection, the main circuit disconnecting device can be effectively cooled. Further, it is preferable to make the inclination large vertically and vertically, and a more remarkable cooling effect can be obtained.

By the way, at the same time as ensuring the insulation distance, the insulation layer
In order to minimize 11, the present inventors have derived that the inclination angle of the inner surface of the insulating layer 11 is optimally 20 to 25 degrees. In determining the optimum tilt angle, a thermal-hydraulic analysis was performed with the tilt angle as a variable, and a heat-fluid analysis in a conventional type and an example type was performed to determine the relationship between the tilt angle and the temperature drop rate. .

In order to obtain the relational expression between the inclination angle of the insulating layer and the surface temperature on the basis of the surface temperature of the contact 15 which produces the most heat, a plurality of kinds of inclination angles were analyzed, and in the case of each inclination angle, A curve approximation of the finger surface temperature is the characteristic diagram of FIG. The curve has an extreme value, and the inclination angle at the extreme value has the highest cooling effect. Further, considering the prevention of collision between insulating layers and the shortest insulation distance when the main circuit disconnecting devices are installed in parallel vertically, the appropriate inclination angle of the main circuit disconnecting device was determined to be 20 to 25 degrees.

From the analysis result, it was confirmed that the conductor temperature and the air temperature in the panel are lowered only by inclining the insulating layer 11. Even when the finger surface temperature was set to an angle of 25 degrees or less, a temperature drop of about 9 ° C was calculated compared to the conventional type. The fact that the temperature drops by 9 degrees in the portion where the temperature rises most significantly greatly improves the thermal performance of the board. Further, it can be confirmed that the temperature of the peripheral parts and the air temperature are lowered due to the cooling of the main circuit disconnecting section. It has been calculated that not only the conductor temperature but also the air temperature causes a temperature drop of about 10 ° C in the air above the circuit breaker.

Further, in the structure shown in FIG. 7, a taper is added to the outer side of the insulating layer 11 of the main circuit disconnecting device having a slanted inner side. This can reduce the amount of resin or the like required for molding. In addition, in addition to improving the ventilation effect due to the inclination, the insulating layer
The amount of heat released by conduction through 11 can be increased, and the cooling effect can be further enhanced.

Next, as shown in FIG. 8, a groove is provided inside the insulating layer 11 so as to expand toward the circuit breaker side.
As in the case described above, an air flow path can be secured and efficient cooling is possible. The shape of the groove may be a triangle, a quadrangle, or a semicircle as shown. Furthermore, a plurality of grooves may be provided.

[0034]

As described above, according to the first aspect of the present invention, the central conductor having one end connectable to the movable electric device, the cylindrical insulating layer formed around the central conductor, and the insulating layer are formed. It has an opening hole provided and a flange to which the insulating layer is fixed, and the distance h between the position where the opening hole is provided and the flange.
Since the ratio h / W of the distance W between the central conductor and the ground flange is 1 or more, the temperature rise of the contact portion including the central conductor can be suppressed.

According to the second aspect of the present invention, a plurality of cylindrical insulating layers are formed, the outermost insulating layer is fixed to the flange, and the opening hole of the insulating layer closest to the center conductor is vertically arranged. Since the opening hole is provided in the insulating layer after that by changing the angle by 90 °, the temperature rise of the contact portion including the center conductor can be suppressed.

Further, according to the invention of claim 5, a central conductor having one end connectable to the movable electric device, a cylindrical insulating layer formed around the central conductor, and a flange to which the insulating layer is fixed Since the central conductor side of the insulating layer is inclined and the inclination angle formed with the central conductor is set to 20 ° to 25 °, the temperature rise of the contact portion including the central conductor can be suppressed.

[Brief description of drawings]

FIG. 1 is a sectional view of a main circuit disconnecting device showing a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the height of an insulating layer 11 of FIG. 1 and withstand voltage characteristics.

FIG. 3 is a sectional view of a main circuit disconnecting device showing a second embodiment of the present invention.

FIG. 4 is a sectional view as seen from the axial direction of FIG.

FIG. 5 is a sectional view of a main circuit disconnecting device showing a third embodiment of the present invention.

FIG. 6 is a characteristic diagram showing the relationship between the inclination angle of the insulating layer 11 of FIG. 5 and temperature.

FIG. 7 is a sectional view of a main circuit disconnecting device showing a fourth embodiment of the present invention.

FIG. 8 is a sectional view of a main circuit disconnecting device showing a fifth embodiment of the present invention.

FIG. 9 is a side view showing the configuration of a typical switching gear.

FIG. 10 is a sectional view of a conventional main circuit disconnecting device.

[Explanation of symbols] 10 ... Central conductor, 11 ... Insulating layer, 12 ... Flange, 14 ... Circuit breaker side central conductor 15 ... Contact, 16, 17 ... Open hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Nakajima 580-1, Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Toshiba Semiconductor System Technology Center

Claims (5)

[Claims] 1. A central conductor having one end connectable to a movable electric device, a cylindrical insulating layer formed around the central conductor, an opening hole formed in the insulating layer, and the insulating layer are fixed. A flange, and a ratio h / W of a distance h between the position where the opening is provided and the flange and a distance W between the central conductor and the flange is 1 or more. Circuit disconnecting device. 2. A plurality of the cylindrical insulating layers are formed, the outermost insulating layer is fixed to the flange, and an opening hole of the insulating layer closest to the center conductor is provided above and below the insulating layer. The main circuit disconnecting device according to claim 1, wherein the opening hole is provided by changing the angle by 90 °. 3. The main circuit disconnecting device according to claim 2, wherein among the plurality of cylindrical insulating layers formed, the height of the insulating layer closest to the central conductor is maximum. 4. At least one insulating layer in which the opening holes are provided above and below is present, and the upper opening hole is larger than the lower opening hole. The main circuit disconnecting device according to any one of the above. 5. A center conductor having one end connectable to a movable electric device, a cylindrical insulating layer formed around the center conductor, and a flange to which the insulating layer is fixed, Inclining the central conductor side, the inclination angle formed with the central conductor
Main circuit disconnecting device characterized by being set at 20 ° to 25 °.