JP2918327B2 - Thyristor valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an air-insulated water-cooled thyristor valve,
In particular, the present invention relates to a thyristor valve having an improved insulation configuration.

(Prior Art) DC power transmission, which has many advantages in system operation, such as large capacity, long distance power transmission and different frequency interconnection, is used in various fields. At present, in some areas in Japan, 250 kv DC power transmission for interconnecting grids is being implemented, and it is desired that the DC power transmission be increased in capacity and voltage in the future.

In such an AC / DC converter in DC power transmission, an AC output input from an AC voltage system is converted into a DC voltage through a converter transformer and a thyristor valve (AC / DC converter) and transmitted. Of these, thyristor valves convert an AC voltage to a DC voltage or a DC voltage to an AC voltage as described above, and air-insulated valves are often used because of their operation results, ease of maintenance and inspection work. Has been
It is stored in a building usually called a valve hole.

FIG. 4 shows the configuration of the thyristor valve. That is, in the thyristor valve, thyristor modules 2... 2 in which electric components such as a thyristor element, a resistor, and a capacitor are housed in a unit are connected in series, stacked, and supported and fixed to the insulating support 3. An electric field alleviating shield 1 is provided above the thyristor valve 2, and a gantry 4 supporting the insulating support 3 is provided at the lowermost part.

FIG. 5 shows an arrangement example of the electric components (only a part is shown) in the thyristor module 2 and a fixing portion between the thyristor module 2 and the insulating support 3. That is, the thyristor module 2 supports a base 8 via an insulator 7 on a module outer frame 6 made of a metal material. The base 8 has a surge blocking coil 9, a thyristor element 10 arranged in series, and a fin 11. The cooling water pipe 12 is attached to the inside of the module outer frame 6, and the fins are inserted through a tube (not shown).
Cooling water is supplied to 11 and the like, and a module support arm 13 is attached to the outside of the module outer frame 6 so as to be supported and fixed via a bolt 15 to a support arm 14 provided on the insulating support 3.

In the configuration described above, since there is a potential difference between the upper and lower thyristor modules 2, it is necessary to secure a predetermined distance for insulation. Here, in terms of electrical insulation,
The severe condition is the bolt 15, the protruding part in the upper part in the thyristor module 2 or the corner part 16 facing the lower part of the thyristor module 2.

(Problems to be Solved by the Invention) Incidentally, the thyristor valve as described above has problems to be solved as described below. That is,
As the voltage of the thyristor valve increases, the potential difference between the upper and lower parts of each thyristor module also increases, the electric field of each part also increases, and a marginal design with less insulation margin is achieved. Therefore, if a structural defect or a functional accident occurs, it easily leads to insulation trouble.

In the case of an air-insulated thyristor valve, since its components such as a thyristor element and a resistor generate a large amount of heat, a water-cooling method is adopted as its cooling means, and cooling is circulated by forcibly circulating cooling water. For this reason, there has been a concern about a danger of water leakage from a joint of a pipe for supplying cooling water, a decrease in insulation due to the leakage of water adhering to an insulator, and a defect in insulation.

For example, as shown in FIG. 5, the cooling water leaks from the cooling water pipe 12 and scatters from the lower thyristor module 2 to the upper thyristor module 2 and from the upper thyristor module 2 to the lower thyristor module 2. Conceivable. At this time, as shown in the figure, it is expected that water droplets will adhere to the joint portion 17 between the column 3 and the lower module 2, particularly around the metal bolt 15. As described above, around the thyristor module 2, the bolt 15,
The corner section 16 has a high electric field during operation. Therefore, when a large amount of water droplets as a conductor is applied to this portion, the creepage insulation strength of the insulating pillar 3 and the insulation strength between the thyristor modules 2 and 2 are greatly reduced.

As described above, in the case of an air-insulated water-cooled thyristor valve, insulation loss due to water leakage occurring in the cooling water pipe 12 is expected as a trouble, and it is necessary to take a countermeasure.

The present invention has been proposed in order to solve the above-mentioned drawbacks of the prior art, and an object thereof is to prevent leaked cooling water from being applied to a metal portion of a connection portion between a thyristor module and an insulating support column. Accordingly, an object of the present invention is to provide a thyristor valve in which the insulation strength between the upper and lower parts of the thyristor module is improved and the insulation stability is improved.

[Constitution of the Invention] (Means for Solving the Problems) According to the present invention, a plurality of thyristor elements and a plurality of electric components are connected to form a thyristor module of one unit, and the thyristor module is connected to an insulating column by a plurality of stages. In a thyristor valve which is mounted in an air-insulated water-cooled manner, an insulating plate is provided so as to cover a metal part at a joint between a thyristor module and an insulating support column.

(Operation) Due to the leakage of cooling water from the thyristor module,
Even if the cooling water is likely to fall on the joint between the insulating pillar and the thyristor module, this is eliminated by the insulating plate, so the cooling water does not fall on the joint and the insulation strength between the upper and lower stages of the thyristor module decreases. Never. In addition, the creeping insulation strength of the insulating pillar is greatly improved. Therefore, the insulation of the entire thyristor valve can be always maintained in a stable state.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a front view showing a main part of one embodiment of the present invention.

In FIG. 1, reference numeral 2 denotes a thyristor module, 3 denotes an insulating support, 13 denotes a module support arm, 14 denotes a support arm, and 15 denotes a bolt, which have the same configuration as the above-mentioned conventional one. The insulating covers 20 and 21 are attached to the insulating support 3 so as to cover the joint between the support and the insulating support 3.

The insulating cover 20 is formed in a step shape having a step with an insulating material. As the insulating material, a Teflon material having a large insulation strength and easy to process is preferable, but of course, another insulating material may be used. The insulating cover 20 is attached to the insulating support 3 so that the insulating cover 20 and the insulating support 3 are in close contact with each other. Further, the insulating cover 20 extends to a position sufficiently covering the cooling water pipe 12 on the thyristor module 2 side.

The insulating cover 21 is made of the same insulating material as the above-mentioned insulating cover 20 and is formed in substantially the same shape.
It becomes 20 and the opposite.

By providing the insulating covers 20 and 21 as described above, even if the cooling water leaks from the cooling water pipe 12, the connection between the insulating column 3 and the thyristor module 2 can be made as in the above-described conventional configuration. The state in which the cooling water falls on the section disappears. Therefore, the insulation strength between the upper and lower stages of the thyristor module 2 does not decrease.

In addition, the creeping insulation strength of the insulating pillar 3 is significantly improved.
This example is shown in FIG. In other words, when investigating the DC discharge voltage (FOV) of each creepage insulation configuration, when the discharge voltage of the shape without the barrier corresponding to the insulating cover is 1.0, it is about 1.5 for one barrier and about 2.0 for two barriers. Voltage. Barriers thus significantly increase the creepage voltage. Although the above description has been made with respect to DC voltage, AC voltage,
There is a similar Barrier effect at the impulse voltage.

In the above embodiment, the insulating covers 20 and 21 are extended toward the thyristor module 2 to a position where the cooling water pipe 12 is sufficiently covered. However, as shown by reference numerals 22 and 23 in FIG. The shape may be such that it covers the hull. With this configuration, the same effect as in the above-described embodiment can be obtained. Further, the number of insulating covers attached between the upper and lower stages of the thyristor module 2 does not need to be particularly limited.

[Effects of the Invention] As described above, according to the present invention, since the insulating plate is installed around the joint with the thyristor module, even if there is water leakage from the cooling water pipe of the thyristor module, it is possible to come. It is possible to prevent a decrease in insulation between the upper and lower stages of the thyristor module due to the above, and in a normal state, it is possible to provide a thyristor valve with stable insulation by significantly improving the insulating strength along the insulating support post due to the effect of the insulating barrier. it can.

[Brief description of the drawings]

FIG. 1 is a front view showing a main part of one embodiment of the present invention, FIG. 2 is an explanatory view showing the operation of one embodiment of the present invention, and FIG. 3 is a front view showing another embodiment of the present invention. FIG. 4 is a front view showing a schematic configuration of a conventional thyristor valve, and FIG. 5 is an explanatory diagram showing a configuration of a main part of the conventional thyristor valve and a state of occurrence of a defect. DESCRIPTION OF SYMBOLS 1 ... Shield for electric field relaxation 2 ... Thyristor module 3 ... Insulating support 9 ... Surge blocking coil 10 ... Thyristor element 11 ... Fin 12 ... Cooling water pipe 15 ... Bolt 17 ... Connection part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-155774 (JP, A) JP-A-58-3790 (JP, U) JP-A-57-92317 (JP, U) 47379 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02M 7/00-7/98 H02M 1/00

Claims (1)

(57) [Claims] 1. A thyristor valve comprising a plurality of thyristor elements and a plurality of electrical components connected to form a unit thyristor module, wherein the thyristor modules are mounted in a plurality of layers on an insulating support, and are air-insulated and water-cooled. 3. The thyristor valve according to claim 1, wherein an insulating plate is provided so as to cover a metal part at a connection portion between the thyristor module and the insulating column.