JPS6129525B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high frequency capacitor, and particularly to an improvement in a cooling structure. In high-frequency capacitors, heat generation due to dielectric loss per unit volume increases in direct proportion to frequency. In this case, heat is dissipated through an insulating layer made of polypropylene or the like, resulting in poor heat dissipation effect and insufficient heat transfer to the outside, resulting in thermal breakdown of the capacitor.
A conventional method for improving this heat dissipation effect will be explained with reference to FIGS. 1 to 3. In FIG. 1, 1 is an electrode foil made of aluminum or the like whose width is narrower than the insulating layers 3 and 4 made of polypropylene, 2 is the insulating layer 3,
This is an electrode foil that is wider than 4 and protrudes on one side.
Both ends 1a and 1b of one of the electrode foils 1 and 2 are arranged inward from the ends 5 of the insulating layers 3 and 4, and one end 2b of the other electrode foil 2 is insulated. An end 1a of the electrode foil 1 that protrudes from the end 5 of the layers 3 and 4 and faces the other end 2a of the electrode foil 2.
A required number of lead wires 6a are inserted into the windings to obtain a capacitor element 9. The electrode foil exposed portion 6b exposed to the outside of the capacitor element 9 thus obtained is clamped with copper strips 7 or the like and fixed with spot welds 8 or the like to facilitate attachment of the cooling pipe. Then, as shown in FIGS. 2 and 3, in order to obtain the desired capacitor capacity, the required number (eight in the figure) of capacitor elements 9 are assembled, and a clamping plate insulator 10 and a clamping plate 11 are interposed. The 9 groups of capacitor elements are tied together with a tightening band 12 to obtain a capacitor body 13. A cooling pipe 14 is attached to the copper strip portion 7 fixed to the electrode foil exposed portion 6b of the capacitor body 13.
Braze with solder, etc. Furthermore, in order to maintain the withstand voltage between the capacitor element 9 and the case 16, a ground insulating plate 15a made of insulating paper or the like is wrapped around the outer peripheral surface of the capacitor body 13 to which the cooling pipe 14 is attached, thereby forming a ground insulating layer 15. After forming, it is stored in a case 16 as shown in FIG. After storage, a predetermined insulating oil 17 is vacuum impregnated to obtain a capacitor 18 . Then, the cooling water is passed through the water inlet 19 of the condenser 18 into the cooling pipe 14 for cooling, thereby making it possible to obtain a condenser with a low temperature rise. Sho 2
0 is a bushing for leading the lead wire 6a led out from the electrode foil 1 to the outside. By the way, in this kind of capacitor, the cooling pipe 14 and the copper strip part 7 are brazed with solder or the like, so the insulating layers 3 and 4 near the exposed electrode foil part 2b become very hot, and the insulating layers 3 and 4 become very hot. There is a risk of melting or carbonization. Furthermore, the solder wax may scatter in the form of vapor and adhere to the vicinity of the end portion 1b of the opposing electrode foil 1, causing corona deterioration. or,
The work of brazing the cooling pipe 14 and the copper strip 7 is very difficult and requires a large amount of solder, which causes an increase in product weight and a rise in product price. Further, in order to place the capacitor element 9 horizontally, the high voltage outlet is located on the side wall of the case. Therefore, the ground insulating layer 15
The disadvantage was that the workability was poor due to the wrapping of An object of the present invention is to eliminate the above-mentioned problems and provide a high-frequency capacitor that has good insulation properties and workability, can lower element temperature, and can increase unit capacity. Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 4 to 9. In the developed view of the capacitor element shown in FIG. 4, insulating layers (dielectrics) 24, 25 and insulating layers (dielectrics) 26, 27 are placed between the opposing electrode foils 21, 22, 21, 23, respectively. Arranged with a spacing of 40mm. Then, one electrode foil 21 is made common, and one foil end 2 of the other electrode foil 22, 23 is used.
2a, 23b are made to protrude from one end of the end portions 24a, 26a, 25b, 27b of the insulating layers 24, 26, 25, 27. Further, the other foil ends 22b, 23a of the electrode foils 22, 23 are covered with insulating layers 24, 26, 25, 2.
7 other ends 24b, 26b, 25a, 27a
It is arranged and wound so as to be more inward, and at the same time, a required number of low voltage lead wires 28 are inserted at the time of winding. After winding the element, as shown in the perspective view shown in FIG. Electrode foils 21, 22, 23 in the figure
Since it can be considered a capacitor, it is exactly 22.2
1 and 23 are connected in series) is obtained. Furthermore, as shown in the perspective view shown in FIG .
2 are assembled, and the capacitor element 32 group is tightly bound with a tightening band 35 via the tightening plate insulation 33 and the tightening plate 34, to obtain a capacitor body 36. Note that 37 is a high-voltage terminal lead wire that bundles the outlet piece 30 together, and 38a and 38b are low-voltage terminal lead wires that bundle the low-voltage lead wires 28 together. And the seventh
The figure shows a high pressure bushing 39, a low pressure bushing 40,
41 and cooling pipes 44, 45 are attached to a cover plate 43. As shown in the sectional view of FIG. 8, the case cover 46 is attached to a case side plate 47 by welding or the like, and the capacitor body 36 is housed therein. The cooling pipes 44 and 45 are arranged adjacent to low voltage electrodes exposed on both side surfaces of the capacitor body 36. 49a is an upper ground insulating layer made of press board or the like, and 49b is a lower ground insulating layer made of press board or the like. The high voltage terminal lead wire 37 is led out to the high voltage bushing 39 and hermetically fixed. Similarly, connect the low voltage terminal lead wires 38a and 38b to the low voltage bushing 4.
0.41 and tightly sealed. Then, the case bottom plate 48 is attached, sealed by welding or the like, and vacuum impregnated with insulating oil 17 to obtain the capacitor 51. In the high-frequency capacitor of the present invention configured as described above, the cooling pipes 4 and 5 are not directly brazed to the capacitor body 36 by soldering or the like, so the insulating layer portion is not exposed to high heat, and therefore quality reliability is improved. do. In addition, since the side surface of the capacitor element body is located opposite to the ground, there is no need to provide ground insulation for the side surface, thereby shortening the work process and simplifying the ground insulation structure. Furthermore, since there is no brazing work such as soldering, it is possible to shorten the work process and improve workability. FIG. 9 shows the relationship between capacitor capacity and element temperature rise for a capacitor having a conventional cooling structure and a capacitor having a cooling structure according to the present invention. Note that A is a conventional condenser and B is a condenser of the present invention. The inner diameter of the cooling pipe is 6 mm, the cooling water flow rate is 1 m/sec, and the frequency is 3000 Hz. As is clear from this result, when the maximum temperature at the center of the element is 45°C and the ambient temperature is 40°C, the maximum single unit capacity under the above conditions is 1500 _KVA for the conventional product, and 2000 _KVA for the inventive product, which is approximately 1.33 times the capacity. can be increased. As described above, the capacitor of the present invention has great practical effects, such as improving workability without deteriorating insulation properties, making it possible to produce a capacitor with low element temperature rise, and increasing unit capacity. . In the above embodiment, an embodiment using a cooling pipe was described, but a cooling panel may also be used.
Of course, it is also possible to use the side wall of the case for the cooling part by self-cooling. As detailed above, the present invention has two electrode foils wound in series with one electrode foil in common, the common electrode foil exposed at the center of the capacitor element, and the other electrode foil exposed to the outside of each insulating layer. A plurality of capacitor elements are assembled, a high-voltage terminal is led out from a common electrode foil, the electrode foils exposed on both sides are set to ground potential, and the capacitor body is housed in a case filled with insulating oil. Therefore, it is possible to provide a high-frequency capacitor that has good insulation properties and workability in the manufacturing process, can lower element temperature, and can increase unit capacity.

[Brief explanation of the drawing]

Fig. 1 is a partial exploded view of a conventional capacitor element, Fig. 2 is a perspective view of a conventional capacitor element, Fig. 3 is a cross-sectional view schematically showing a conventional high-frequency capacitor, and Fig. 4 is a part of a conventional capacitor element. FIG. 5 is a perspective view of the capacitor element used in the high-frequency capacitor of the above example, and FIG. 6 is a partial exploded view of the capacitor element used in the high-frequency capacitor of the above example. Perspective view,
FIG. 7 is a perspective view of the cover to which the cooling pipe used for the high-frequency condenser of the above embodiment is attached;
The figure is a cross-sectional view schematically showing the high frequency capacitor of the above embodiment, and FIG. 9 is a graph comparing the capacitance and temperature rise of a conventional capacitor and a high frequency capacitor of the present invention. 24, 25, 26, 27...dielectric, 21, 2
2, 23... Aluminum foil, 32... Capacitor element, 4
3...Case cover, 44, 45...Water cooling pipe.

Claims (1)

[Claims] 1. Among the first, second, and third electrode foils, the first electrode foil is used in common, and the remaining second and third electrode foils are wound in a stacked state with an insulating layer interposed therebetween, In a high frequency capacitor in which two pieces are wound in series, a plurality of capacitor elements are assembled in which the first electrode foil is exposed at the center and the second and third electrode foils are exposed to the outside of each insulating layer, A high voltage terminal is led out from the exposed portion of the first electrode foil, lead wires are electrically connected to the second and third electrode foils exposed on both sides to provide a ground potential, and the capacitor body is housed in a case. , a high-frequency capacitor filled with insulating oil. 2. In what is stated in claim 1,
A high-frequency capacitor that features electrode foils exposed on both sides that are cooled by water-cooled pipes. 3 In what is stated in claim 1,
A high-frequency capacitor that features electrode foil exposed on both sides that is cooled by a water-cooled panel.