US2055346A - High voltage electrical apparatus - Google Patents

Description

Sept. 22, 1936. w. FOSTER HIGH VOLTAGE ELECTRICAL APPARATUS Filed April 50, 1935 Inventor Levin W- Foster, by 77 m His Attorneg- Patented Sept. 22, 1936 UNITED STATES HIGH VOLTAGE ELECTRICAL APPARATUS Levin W. Foster, Pittsiield, Mass., assignor to General Electric Company, a corporation of New York Application April 30, 1935, Seriai No. 19,001

I 7 Claims. (Ci. 175- 360) My invention relates to high voltage electrical apparatus, more particularly to high voltage liquid-immersed apparatus such as transformers and reactors. Such apparatus is usually enclosed in a metal casing containing a suitable insulating liquid and the high voltage terminals of the apparatus are brought out of the casing through suitable insulating bushings. These bushings are expensive and one of the objects of the-invention is to provide an arrangement which does not require their use. Unless the capacity of the apparatus is very small, its temperature may become excessive during operation unless there is some eflicient way of cooling it. Another object of theinvention is therefore to provide an improved arrangement for carrying away and dissipating the heat generated in the apparatus during its operation.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which Fig. 1 is a view in elevation of a high voltage transformer and means for cooling it, the transformer and its cooling means being arranged in accordance with the invention; Fig. 2 is a plan view of the transformer and its cooling means shown in Fig. l and Fig. 3 shows diagrammatically the arrangement of the windings in the transformer.

Like reference characters indicate similar parts of different figures in the drawing.

The transformer it shown in Fig. 1 includes a series of individual units, each having three windings M, l2, and it. The windings M are all connected in series between a high voltage terminal i l and a ground connection it. The windings i2 and it are connected to form coupling circuits between the windings i i to assure a uniform distribution of voltage throughout the units. The winding it of the unit next to the ground connection i5 is provided with terminals it for connection to an external low voltage circuit. Each transformer unit surrounded by a cylindrical wall of insulating material such as porcelain, these walls being secured together to form a common insulating casing H for the transformer Iii. The transformer it! with its casing W is mounted on a hollow metal base J8 which may also support some insulating bushings IQ for the 50 low voltage terminals IS. The cover 2d of the easing ll is insulated from grci'm-d by the casing so that it need not be insulated from the high voltage terminal l4 and this terminal It may therefore be in the form of a simple terminal post.

The transformer I0 is immersed in an insulating liquid 2| which fills the casing H and extends through a pipe 22 to a conservator 23 provided with a breather 26 to permit expansion and contraction of the liquid in the temperature changes. The pipe 22, which with the conservator 2t and its breather 24 is supported on the cover 29, is connected to and communicates with the header at one end of a horizontally disposed metal heat radiator 25. The header at the other end of the radiator 25 communicates through and is sup= ported by a pipe 26 which is in turn supported by a vertical hollow post 27 spaced from the casing I? and mounted on the hollow base 18 with which it communicates also. The liquid 20 not only fills the casing H but also extends and may circulate through the radiator 25, the hollow insulating post 21 and the hollow base l8, back into the lower end of the casing ill. No insulation is necessary between the high voltage terminal it and the radiator 25 and conservator 23 because the radiator and conservator are efi'ectlvely insulated, as well as supported, by the casing ii and the hollow post 2?. Y

The high voltage terminal it is connected by a conductor 28 and a protective devic'e', such as a fuse 29, to a terminal 39 arranged for connection to an external high voltage circuit. The hollow post 2i is shown as being formed in sections connected together by liquid-tight joints and the fuse 2Q is mounted between a support 35 at the top of the post 2'? and the joint between the upper two sections of the post.

While the transformer i t is in operation, it generates heat which must be dissipated to avoid excessive temperature of the transformer. This heat is absorbed by the liquid 29 surrounding the transformer, the heated liquid then rising by convection into the radiator 25 where it is cooled, the cooled liquid then descending throughthe hollow post 2i and then flowing through the hollow base it back into the casing ll, ready to absorb more heat. In the arrangement which has been described, the radiator 25 extends laterally in a more or less horizontal position from the upper part of the casing ill, as shown in Fig), 1, so that it is well exposed to the surrounding ali to which it may dissipate heat very effectively. Some additional heat may also be dissipated/oi course through the walls or the post 2i and 'the metal base it.

illustrating a particular arrangement and application thereof but it will be apparent that changes may be made without departing from the spirit of the invention and the scope of the post spaced from said casing and supporting and communicating with the other end of said radiator, means providing communication between the lower ends of said casing and post, and an insulating liquid in said casing, radiator and post.

2. The combination with electrical apparatus of an insulating casing therefor, a hollow insulating support spaced from said casing, a metal heat radiator supported by the upper ends of said casing and support, means providing communication between the lower ends of said casing and support, and an insulating liquid in said casing, radiator and support. I

3. The combination with electrical apparatus of an insulating casing therefor, a hollow base supporting and communicating with said casing, a hollow insulating support spaced from said casing and mounted on and communicating with said base, a metal heat radiator supported by and providing communication between the upper ends of said casing and support, and an insulating liquid in said casing, radiator, support and base.

4. The combination with electrical apparatus of an insulating casing, a hollow insulating support spaced from said casing, means providing communication between the lower ends of said casing and support, a metal heat radiator supported substantially horizontally by and communicating with the upper ends of said casing and support, and an insulating liquid in said casing, radiator and support.

5. The combination with electrical apparatus of an insulating casing therefor, a high voltage terminal for said apparatus on the upper end of said casing, a hollow insulating support spaced from said casing, a metal heat radiator supported by and providing connection between the upper ends of said casing and support, means providing communication between the lower ends of said casing and support, a protective device and a terminal mounted on said support, and connected to said high voltage terminal, and an insulating liquid in said casing, radiator and support.

6. The combination with electrical apparatus of an insulating casing therefor, a metal heat radiator extending laterally from the upper part of said casing and communicating therewith, the end of said radiator adjacent the casing being supported thereby, an insulating support for the other end of the radiator, and an insulating liquid in said casing and radiator. Y

7. The combination with electrical apparatus of an insulating casing therefor, a metal heat radiator extending laterally from the upper part of said casing and supported at one end thereby, said radiator communicating with the upper part of said casing, insulating means supporting the other endof said radiator providing communication between said radiator and the lower part of said casing, and an insulating liquid in said casing and radiator.

' i "LEVIN W. FOSTER.

Images