JPS6380768A - Thyristor valve - Google Patents

Abstract

PURPOSE:To shorten the insulation size of a support by surrounding the periphery of the support under a thyristor valve body with an insulating plate, and sealing insulating gas therein. CONSTITUTION:A thyristor valve support 21 is composed of a coolant insulating pipe 19 for absorbing heat in a thyristor valve body 12, a light guide for feeding a firing signal, and an insulating post 18. insulating gas (e.g., SF6) is so sealed as to hold airtightness at the periphery of the components. Corrugations 27 are attached to the outer periphery of an insulating plate 12 to increase the creeping passage. Thus, the support 21 is strengthened in insulation by sealing SF6 gas having pressure resistance of several times as large as air in the plate 23, and the exterior is extended by the corrugations 27 at the creeping distance, thereby improving its dielectric breakdown strength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object 1 of the Invention] Field of Application in C1n Industry The present invention relates to a thyristor valve in which an improved method of insulating an insulating support part in an air-insulated thyristor valve is implemented.

(Conventional technology) With the increase in electricity demand in recent years, DC power transmission, which has many advantages in system operation such as large capacity, long-distance power transmission, and power interchange between different frequency systems, has been used in a wide variety of fields. There is.

Currently, 250KV DC power transmission is being implemented in some areas in Japan to connect the grid, and it is hoped that this DC power transmission will have a larger capacity and higher voltage in the future.6 Figure 3 shows the conventional A typical connection diagram of an AC/DC converter station for DC power transmission is shown. This AC/DC converter station performs 12-phase rectification, and voltage is supplied from the 3-phase AC voltage system 1 to the thyristor valve groups 4 and 5 via converter transformers 2 and 3, and then converted to DC voltage. It is something. Air-insulated thyristor valves are used as the thyristor valve group 4.5 due to their operational performance and ease of maintenance and inspection work, and are usually referred to as valve holes 6.7.

It is housed in a building. Further, a lightning arrester 8.9 is provided to electrically protect the thyristorbastic groups 4, 5.

FIG. 4 shows peripheral equipment for such a conventional AC/DC converter. Note that FIG. 4 shows the low-pressure side thyristor valve group 5 and its peripheral equipment in FIG. 3. That is,
From the three-phase AC voltage system 1, through the converter transformer 3,
It is connected to an air insulated thyristor valve 12 which is made up of two thyristor valves, and an electric appliance 15 is connected to the air insulated thyristor valve 12. It is housed in the valve hole 11. Further, the thyristor valve hole 11 is provided with a blocking coil 13 against an invading surge voltage and a through-wall bushing 14 that guides the DC output to the outside of the thyristor valve hole 11 .

(Problems to be Solved by the Invention) In the conventional AC/DC converter station configured as described above, the thyristor valve 12 installed in the thyristor valve hole 11 is designed to increase the capacity and voltage of the AC/DC converter. The size will increase accordingly. That is, as shown in FIG. 5, the thyristor valve 12 is constructed by combining two parts into one, and several thyristor elements of several thousand volts are connected in series. -Unit thyristor assembly (hereinafter referred to as module) 1
6 are supported by insulating columns 18, and are arranged in multiple stages at predetermined intervals. In the thyristor valve 12 configured in this way, with the increase in voltage and capacity, the module itself also has a thyristor element,
As internal elements such as capacitors and resistors become larger, the thyristor valve 12 becomes larger.
will also become larger. In this way, as thyristor valves become larger due to higher voltage, the valve hole 11 for housing the thyristor valve must also become larger.6 For example, it is particularly desirable to reduce the height of the thyristor valve itself. There is. Now, in this height reduction, the reduction in the height of the insulating support part 21 at the lower part of the thyristor valve body 12 shown in FIG. 5 is drawing particular attention. However, this part includes an insulated support column 18 for supporting the valve body 12, an insulated pipe 19 for cooling water sent into the valve for heat absorption. It consists of a thyristor point, a light guide 20 for sending arc signals, and the like. As a result of past improvements and innovations, these insulating parts are close to the limit design, to the point where no further reduction in insulation in air can be expected.

Therefore, forcibly reducing the insulation size may lead to instability of the insulation of the support section 21, insulation troubles, etc. However, as mentioned above, in preparation for future increases in high voltage and capacity, insulation reduction is an urgent RM and a problem that must be solved. Against this background, drastic insulation measures were needed.

The present invention was proposed to solve the problems of the conventional thyristor valve as described above, and its purpose is to stabilize the insulation of this part by improving the insulation structure of the insulating support part. The object of the present invention is to provide a small and reliable thyristor valve by reducing insulation dimensions.

[Structure of the invention]

(Means for solving problems and their effects) Figure 1 shows
In Fig. 0, which shows an example in which improvements have been made to solve the problem, the lower part of the thyristor valve body 12 is surrounded by an insulating plate 23, and an insulating gas is filled inside. The insulation is strengthened by adding pleats to the outer periphery and extending the creepage distance. By implementing these measures, the insulation dimensions of the support section 21 can be reduced.

(Example) FIG. 1 shows an example. FIG. 1 is a particularly enlarged view of the thyristor valve support part 21 in FIG. ．． Light guide device 2 for sending signals for ignition of thyristor elements
0. Insulating column 18 for supporting the thyristor valve body
It is made up of etc.

An insulating plate 23 is placed around these parts to maintain airtightness.
is installed, and the inside is filled with an insulating gas equivalent to atmospheric pressure (for example, S
F,) is enclosed. Additionally, pleats are attached to the outer periphery of the insulating plate to lengthen the creepage path.

FIG. 2 shows an example of how the insulating plate 23 is installed between the thyristor valve lower shield 22 and the pedestal 26.

As shown in the figure, grooves 24 and 25 into which the insulating plates 23 can be fitted are provided in the lower shield 22 and the pedestal 26, respectively.

An insulating plate 23 is installed. Then, an insulating adhesive 28 for airtightness is attached to the outer periphery of the grooves 24 and 25.

The insulating support part 21 configured in this way has the insulating plate 23
The inside of the tube is reinforced with insulation by filling it with gas, SF, which has several times the pressure resistance of air. On the outside, the creepage distance is extended by installing pleats, which improves the dielectric strength. As a result, the dielectric strength of the support portion 21 is significantly improved. This makes it possible to reduce the size in the height direction. Also.

Water pipes and light guides were conventionally affected by outside temperature, humidity, dust, etc. by filling insulating gas (SF, gas) inside the insulating plate 23 and sealing it.

The creeping insulation part of the insulating column will not cause any problems, so
Insulation becomes stable. This improves the reliability of the insulating support.

(Other examples) ■ In this example, the insulating gas to be filled is SF.

Although the explanation has been made using gas, other insulating gases may also be used.

■ Although the insulation board 23 was not specified, it can be made of FRP,
Any material with high insulating properties, such as epoxy material or PVC, will suffice, and the thickness of the material should be one that can withstand the internal gas pressure and the mechanical force applied.

■ The dimensions of the folds attached to the outer periphery of the insulating plate 23 are not specified. Any shape that allows for a long creepage path is fine.

〔Effect of the invention〕

As explained above, by adopting the structure of the present invention, the insulation of the insulating support part is strengthened, and the insulation dimension of this part is reduced. In addition, since it is not affected by the external environment, the insulation is stable and insulation reliability is increased.

These effects make it possible to reduce the size of the thyristor valve in the height direction and improve insulation reliability.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, FIG. 3 is a diagram showing a connection diagram of an AC/DC converter station, and FIG.
The figure is a perspective view showing the arrangement of peripheral equipment of the AC/DC converter, and FIG. 5 is a front view of the AC/DC converter. 1... Three-phase AC voltage system 2.3... Converter transformer 4.5, 12... Thyristor valve 6.7, 11... Valve hole 8.9.15... Arrester 10 DC line 13
...Blocking reactor 14...Wall bushing 16...Module 17
...High voltage shield 18...Insulation column 19...
Insulated pipe 2o...Light guide device 21...
・Valve main support part 22... Valve lower shield 23... Insulating plate 2
4, 25... Groove 26 Frame 27... Extended insulating plate 28... Adhesive Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) In an air-insulated thyristor valve in which a unit of thyristor element assembly in which several thyristor elements are connected in series is supported by an insulating column and arranged in multiple stages at a predetermined interval, the insulating column at the bottom of the thyristor valve. The insulated support part, which is made up of insulated pipes, etc., is surrounded by an insulating plate to maintain airtightness, and an insulating gas is further filled inside to form the insulated support part. thyristor valve. (2) The thyristor valve according to claim 1, characterized in that the outer peripheral portion of the insulating plate is provided with pleats in a substantially horizontal direction.