JPS583383B2 - thyristor stack - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a plurality of flat thyristors, each of which has a flat shape. A gas-cooled thyristor stack is formed by laminating each other with a cooling body provided on the end face and elastically holding the thyristor stack.

Such thyristor stacks are available.

This stack is integrated into a bridge circuit or connected in series when a larger number of flat thyristors is used.

For example, a device for air cooling a flat thyristor is known from West German Patent Publications No. 2107008, No. 2107009 and No. 2107319. A pipe is provided.

In the device known from DE 21 07 319 A1, the heat pipe is bent in an L-shape and is located symmetrically with respect to the central axis of the flat thyristor.

A device consisting of one flat thyristor and two heat pipes is each pressed and held by a pressing device.

The free ends of both heat pipes are provided with cooling fins to increase the heat transfer area to the gaseous cooling medium.

Here, the term heat pipe is used in the field of cooling technology, for example, in US Pat. No. 2,350,348,
Magazine “Chemie-Ingenieur-Techn
ik" Vol. 39, No. 1, 1967, pp. 21-26.

Such a heat pipe consists of a pipe closed at both ends, the inner wall of which is covered with a capillary core.

The wick is soaked with a liquid refrigerant such as freon, methanol, ether, acetone, benzol or water.

When the part called the evaporation part of the heat pipe is heated,
Here the refrigerant evaporates from the wick and the vapor flows in the direction of the temperature gradient.

This vapor condenses in another cooled section called the condensing section, where the vapor releases heat of vaporization.

The refrigerant condensed in the condensing section is returned within the core to the heated evaporation section of the heat pipe by capillary action.

Thus, a refrigerant circuit is created that operates independently of external forces and even against gravity.

For example, electrically insulating heat pipes are described in West German Utility Model No. 7227365 or German Patent Application No. 2120474.

In this heat pipe, the evaporating section and the condensing section are electrically separated using a cylindrical intermediate piece made of electrically insulating material.

In this case, the wick consists of an electrically insulating material, at least in the area of the intermediate piece, and the refrigerant is non-conductive.

For example, a flat thyristor in which devices such as those known from West German Patent Application Nos. 2204589 to 2107008 are stacked such that the axes of heat pipes of adjacent cooling bodies are shifted from each other while rotating with respect to the stacking axis. An air-cooled thyristor stack equipped with the following has already been proposed.

With this gas-cooled thyristor stack, good cooling of all heat pipes and thus all flat thyristors is possible.

The object of the invention is to improve the device mentioned at the outset, to further improve the cooling of an entirely flat thyristor, and at the same time to minimize the dimensions of the thyristor stack.

According to the invention, this object is such that each cooling body is provided with a heat pipe which overhangs the thyristor stack, the free end of each heat pipe has a cooling fin, and each heat pipe is bent in an L-shape and interdigitated with each other. This is achieved by alternately disposing the heat pipes of adjacent cooling bodies on opposite sides with respect to the plane containing the central axis of the thyristor stack.

In the case of the thyristor stack according to the invention, good cooling is utilized for all flat thyristors of the thyristor stack by providing each thyristor with a heat pipe.

Since the adjacent heat pipes are arranged alternately on opposite sides with respect to the plane containing the central axis of the thyristor stack, the heat pipes are generally located in two planes extending parallel to each other.

As a result, the cooling fins of adjacent heat pipes are always located on the opposite side of the plane containing the silice lamination axis, resulting in a flat and compact structure in which the space occupied by the cooling device is small.

Furthermore, according to the present invention, since the cooling fins of the heat pipe are alternately located on opposite sides of the plane containing the thyristor lamination axis, the dimension of the cooling body in the lamination axis direction must be long enough so that adjacent cooling fins do not come into contact with each other. There is no need to do this, and the number of laminated thyristors can be increased and doubled accordingly.

The present invention will be explained in detail below with reference to the illustrated embodiments.

The thyristor stack shown in FIG. 1 includes a plurality of flat thyristors 1 connected in series, with a cooling body 2 in contact with each end face of the flat thyristors in a good heat conduction state.

Via the insulating piece 3 and the pressing piece 4, the flat thyristor 1 and the cooling body 2 are substantially connected to the threaded bolts 5, 6 and the two pressing plates 7,
It is held within a frame consisting of 8.

One of the insulating pieces 3 rests on the pressing piece 4.

The structure of the pressing piece 4 is disclosed in West German Patent Application Publication No. 1914.
It is described in detail in Publication No. 790.

The pressure piece 4 essentially has a disc spring 10 as an energy storage element, by means of which an elastic pressure force is exerted on the cooling body 2 and the flat thyristor 1 .

As a result, electrical and thermal contact between the cooling body 2 and the flat thyristor 1 is ensured.

The electrical terminals for the flat thyristor 1 are connected directly to the cooling body 2
It can be provided in

These terminals are not shown in FIG. 1 for clarity of drawing.

Each cooling body 2 has a heat pipe 11.

This metal hype is made from copper, for example.

The evaporator part of the heat pipe extends into the cooling body 2 to obtain a good thermal coupling.

The free end of each heat pipe serves as a condensing section and is provided with plate-shaped cooling fins 11b to 11d extending perpendicularly to the heat pipe.

The free end 11a of the heat pipe 11 has coupling pieces 13, 14
It is held in a recess 12a of a support 12 which is fixed via the push plate 7 or 8 of the push device for the thyristor stack.

Next, it will be explained in more detail that the cooling medium flow path is formed by the support body 12, the coupling pieces 13 and 14, and the flow guide plate 19 attached to the pressing device.

Between the cooling fins 11b and the cooling body 2, in the embodiment shown in FIG. 1, a flexible or elastic cylindrical piece 11c is arranged so as to be located within each heat pipe 11.

This elastic cylindrical piece 11c equalizes stresses that may arise due to thermal expansion or due to manufacturing tolerances.

If the free end 11a of the heat pipe 11 is not inserted unlike this embodiment, this flexible cylindrical piece 11
Although it is possible to omit step a, there is a risk that the mechanical action applied to the end of the heat pipe will be completely applied to the cooling body 2 and thus to the flat thyristor 1.

It is desirable that the flexible cylindrical piece 11c be constructed so that it can be self-retained.

The heat pipe 11 is thus also self-supporting and the pipe need only be held on the support 12.

In this embodiment, the flexible cylindrical piece 11C is a corrugated pipe made, for example, from a copper alloy.

FIG. 1 furthermore shows two embodiments of cooling fins.

The cooling fins 11b protrude from the heat pipes 11 in such a size that they do not come into contact with adjacent heat pipes and do not overlap.

Furthermore, as shown at 11d in FIG. 1, the cooling fins on adjacent heat pipes can be sized so that they overlap without touching.

This increases the heat exchange area of the cooling fins while leaving the space occupied by the thyristor stack virtually unchanged.

FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1.

From this figure, it can be seen that the heat pipe 11 is bent into an L shape.

The heat pipes of mutually adjacent cooling bodies in this case extend from the thyristor stack to the central axis 15 of the thyristor stack.
They project laterally to alternately opposite sides with respect to a plane 16 that intersects the central axis.

The free ends 11a of adjacent heat pipes 11 thus lie on separate planes 17, 18, which in this embodiment are parallel to each other.

In this way, a flat design with a small footprint is obtained, which also allows good guidance of a gaseous cooling medium, such as air, for example.

For guiding this cooling medium, the support 12, the two connecting pieces 13, 14 and the flow guide plate 19 are used, as can be seen in FIG.

These components form the wall surface of the air flow path in which the cooling fins 11b to 11d of the heat pipe are arranged.

FIG. 3 is a plan view of the heat pipe with the support 14 removed.

It can be seen from this figure that the heat pipes 11 of mutually adjacent cooling bodies are located alternately in planes 17 and 18 due to their L-shaped shape.

Furthermore, this figure shows that the arrangement according to the invention allows the cooling fins 11b to 11d to be arranged rotationally symmetrically with respect to the central axis 11g of the heat pipe 11 to which they are attached.

Rubbing allows for even heat dissipation from all sides.

FIG. 4 shows, partially in section, a heat pipe as provided in a thyristor stack according to the invention.

In the evaporator section, the heat pipes are fixed in the cooling body 2 in such a way that a reliable thermal connection occurs, for example by creasing.

The heat pipe passes through the cooling body, and the short end protruding from the cooling body is available for sealing the heat pipe after injection of coolant.

A wick 11e is arranged inside the heat pipe 11, which is shown within the flexible cylindrical piece 11 shown in cross section.

Within this range, the core does not stick tightly to the wall of the corrugated pipe;
Simply riding on the waves.

Regarding the materials that can be used as the core 11e and regarding the refrigerant injected into the heat pipe, a detailed explanation can be found in the aforementioned publications.

Also when the cooling body 2 is used for current flow, it is usually not necessary to keep the air-cooled heat pipe 11 in a voltage-free state.

If this becomes necessary in special cases, each heat pipe 11 can be provided with an electrically insulating intermediate piece 11f, which in the embodiment of FIG.
1b and the heat pipe 11c.

In this embodiment, the material of the electrically insulating intermediate piece 11f is ceramic, which customarily has ribs to increase the creepage distance.

When such electrically insulating intermediate pieces 11f are provided, it is necessary to make the core 11e from an electrically insulating material at least within the range of each intermediate piece 11f and to use an electrically insulating refrigerant in the heat pipe.

Such wicks and such refrigerants are likewise detailed in the above-mentioned publications, in particular German Utility Model No. 72 24 356.

In summary, by adopting the configuration according to the present invention,
By using a heat pipe, it is possible to obtain a gas-cooled type, for example, an air-cooled type thyristor stack, which greatly improves the cooling of the thyristor.

The structural dimensions of the thyristor stack according to the invention are hardly increased compared to known air-cooled thyristor stacks and, as a result of the special shape of the heat pipes and the support of the heat pipes, good cooling air guidance can be achieved using simple means. can be achieved.

Due to the flexible or elastic design of the heat pipe, thermal and mechanical stresses are compensated and the thyristor stack according to the invention can also be provided for applications requiring vibration resistance.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of an embodiment of the present invention, Fig. 2 is a longitudinal sectional front view taken along the line ■-■ in Fig. 1, and Fig. 3 is a partially cutaway plan view of the stack shown in Fig. 1. , FIG. 4 is a partially cutaway front view showing one heat pipe taken out. 1... Flat thyristor, 2... Cooling body, 11...
Heat pipe, 11a...Free end of heat pipe, 11
b, 11d... Cooling fin, 17... Central axis of thyristor stack.

Claims (1)

[Claims] 1 A plurality of flat thyristors are stacked and elastically held together with a cooling body provided on each end face, and each cooling body is equipped with a heat pipe, and this heat pipe is connected to the thyristor stack on both sides. The thyristor laminates are arranged so that the free ends thereof are alternately opposite to the plane including the central axis of the thyristor stack, and the free ends are provided with cooling fins. A thyristor stack characterized by: