Gas insulated switchgear device

Abstract: Main buses 1 and 2 which are to be sectioned into two on the respective axes are disposed on two parallel straight lines facing each other, further at the outside of the bus sectioning portions for the main buses 1 and 2 auxiliary buses 6 are disposed in parallel with the respective axes of the corresponding main buses, one end of the auxiliary bus is connected to the corresponding end of the main bus by a branching bus 7 along which a main bus connected potential transformer 11 and a main bus use earthing switch 13 are provided, further, a branching bus 9 led out from one of leading out portions for a circuit breaker 5 extends over the auxiliary bus 6 and is connected to the corresponding main bus via a disconnecting switch 8a and at the midway of a branching bus connecting between the disconnecting switch 8a and the main bus a main bus connected potential transformer 10 and a main bus working use earthing switch 12 are provided. Whereby, because of the concentrated disposition of the main bus connected ptential transformers and the main bus working use earthing switches in the respective bus sectioning units, the entire arrangement structure of the gas insulated switchgear device is rationalized and compacted, thereby the cost therefor is improved.

Description: Background of the Invention The present invention relates to an arrangement structure of a bus sectioning unit in a double bus type gas insulated switchgear device wherein potential transformers to be connected to a main bus and earthing switches used for working on the main bus are disposed in concentration. With regard to the arrangement structure of the gas insulated switchgear devices many investigations have been performed until now. As one of prior art examples, JP-A-4-299007(1992) discloses a gas insulated switchgear device, in particular a bus sectioning unit therefor. Fig.10 shows a single connection diagram of a bus sectioning unit portion in a gas insulated switchgear device and Fig.ll shows the arrangement structure thereof. The entire length L' of the bus sectioning unit including a main bus potential transformer (PT) unit 16 reaches up to 27 m and further the area required therefor is great. JP-A-2-273009(1990) discloses a gas insulated switchgear device with the features included in the first part of claim 1. In this device, the bus use earthing switches and bus use potential transformers are incorporated in the connecting buses on one side of the arrangement, with no further concentration of structural parts being envisaged. Summary of the Invention It is an object of the present invention to realise a more compact gas insulated switchgear device thereby reducing the lengths on the main and branching buses therein in addition lowering to the production costs and the installation space required. This object is met by the switchgear device defined in claim 1. In an embodiment of the invention, gas circuit breakers for the bus sectioning unit are disposed further outside of both main buses and auxiliary buses, one of branching buses led out from both poles of the gas circuit breaker is directly connected to the auxiliary bus via a disconnecting switch, the other branching bus extends upto the upper portion of the main bus passing over the auxiliary bus and is connected via a disconnecting switch and a connecting conductor to the main bus, and at the connecting conductor between the disconnecting switch and the main bus a potential transformer to be connected to the main bus and an earthing switch used for working on the main bus are disposed, further at another connecting conductor connecting the main bus and the auxiliary bus without routing a circuit breaker another potential transformer to be connected to the main bus and another earthing switch used for working on the main bus are likely disposed, thereby the arrangement structure of the gas insulated switchgear device including the above mentioned elements according to the present invention is confined in a length within about 13.5 m which is comparable to the entire length of the conventional bus sectioning units. Through the concentrated disposition of the main bus PT S and the main bus earthing switches (ES S ) in the bus sectioning units and, the conventional necessity of providing an installation space for the main bus PT S and the main bus ES S in the main bus arrangement is eliminated and thus space reduction of the entire arrangement structure of the gas insulated switchgear device is realized. Further, because of unnecessity of providing PT S for other feeder units and for main bus connecting units a standardization of the gas insulated switchgear device is realized and thus except for the disposition of the main bus PT S and the main bus ES S the main bus sectioning units and according to the present invention are constituted in the same arrangement structure as of a main bus connecting unit. Namely, the positional relationship and the arrangement structure of gas circuit breakers, either main bus or and auxiliary bus in the main bus sectioning units and are identical with those of gas circuit breakers and two main buses and in the main bus connecting unit. Accordingly, a standardization of constitutional elements is realized between the main bus sectioning units and the main bus connecting unit. Brief Description of the Drawings Fig.1 is a plan view of one embodiment of the gas insulated switchgear device according to the present invention ; Fig.2 is a side elevation of the bus sectioning gas circuit breaker portion taken along the line II-II in Fig.1 of the one embodiment in the gas insulated switchgear device according to the present invention ; Fig.3 is a side elevation showing the connecting portion of the main bus and the auxiliary bus taken along the line III-III in Fig.1 of the one embodiment in the gas insulated switchgear device according to the present invention ; Fig.4 is a side elevation of the bus connecting unit in the gas insulated switchgear device taken along the line IV-IV in Fig.1 ; Fig.5 is a plan view of another embodiment of the gas insulated switchgear device according to the present invention ; Fig.6 is a side elevation of the bus sectioning gas circuit breaker portion taken along the line VI-VI in Fig.5 of the other embodiment in the gas insulated switchgear device according to the present invention ; Fig.7 is a side elevation showing the connecting portion of the main bus and the auxiliary bus taken along VII-VII in Fig.5 of the other embodiment according to the present invention ; Fig.8 is a side elevation of the connecting portion of the main bus and the auxialiry bus of still another embodiment in the gas insulated switchgear device according to the present invention ; Fig.9 is a plan view of a further embodiment of the gas insulated switchgear device according to the present invention ; Fig.10 is a single line connecting diagram of bus sectioning units, main bus PT units and the portions nearby in a gas insulated switchgear device ; Fig.11 is a plane view of a conventional gas insulated switchgear device corresponding to the single line connection diagram shown in Fig.10 ; and Fig.12 is a side elevation seen from the line XII-XII in Fig.11 showing the arrangement structure of the main bus connected PT S and the main bus working use ES S in the conventional gas insulated switchgear device. Detailed Description of Preferred Embodiments Hereinbelow embodiments of the present invention are explained specifically with reference to the drawings. Fig.1 is a plan view showing a main bus sectioning unit and the vicinity thereof for a double bus type gas insulated switchgear device of one embodiment according to the present invention, wherein vertical type circuit breakers are exemplarily used for the main bus sectioning use gas circuit breakers 5. Gas insulated main buses 1 and 2 are a linearly constituted three phase collective type and are disposed in an opposing manner on two parallel straight lines at substantially the same height level. Both the gas insulated main buses 1 and 2 are sectioned into two portions at the bus sectioning position, and gas insulated main bus sections 1a and 1b, and 2a and 2b are respectively to be connected by the main bus sectioning units 3 and 4. The main bus sectioning units 3 and 4 are primarily constituted by the gas circuit breakers 5, the gas insulated auxiliary buses 6, 6' and gas insulated branching buses 7 or 9. The gas insulated auxiliary buses 6, 6' are a three phase collective type and the others, for examples branching buses 7 and 9, are phase isolated type. Fig.2 is a diagram taken along the line II-II in Fig.1 and shows the construction structure relating primarily to the gas circuit breaker 5. The gas insulated main bus 2 and the gas insulated auxiliary bus 6' are disposed in parallel at a same height level, and further the gas circuit breaker 5 is disposed at the opposite side of the auxiliary bus 6' from the side where the main bus 2 is disposed. In Fig.2 embodiment, a vertical type circuit breaker is used for the gas circuit breaker 5 and the directions of two leading out conductors from the gas circuit breaker 5 toward the auxiliary bus 6' are substantially horizontal. The leading out portion from the lower portion of the circuit breaker 5 is connected to the auxiliary bus 6' via a disconnecting switch 8b which is disposed vertically above the auxiliary bus 6', on the other hand the leading out portion from the upper portion of the gas circuit breaker 5 extends above the auxiliary bus 6' by means of the branching bus 9 and is connected to the main bus 2 via a disconnecting switch 8a which is disposed vertically above the main bus 2. As shown in Fig.2, the disconnecting switch 8a disposed above the main bus 2 is not at the same height level as of the disconnecting switch 8b disposed above the auxiliary bus 6 but at a higher position in accordance with the height level of the branching bus 9. Further, at the branching bus portion between the disconnecting switch 8a and the main bus 2 a main bus connected PT 10 and a main bus use ES 12 are disposed. On the other hand, Fig.3 is a diagram taken along the line III-III in Fig.1 and shows an arrangement structure relating primarily to the gas insulated branching bus 7. The gas insulated main bus 2 and the gas insulated auxiliary bus 6' are respectively provided with an upwardly directing opening portion, and branching buses led out perpendicularly from the respective opening portions are connected by the horizontal branching bus 7. Further, along the length of the branching bus 7 a main bus connected PT 11 and a main bus use ES 13 are provided. Thus constituting the bus sectioning units 3 and 4 the main bus connection use PT S 10 and 11 and the main bus use ES S 12 and 13 can be concentratedly disposed in the bus sectioning units 3 and 4. Accordingly, the conventionally required space for the bus PT units 16 as shown in Fig.ll is eliminated, thereby the length in the main bus axial direction of the gas insulated switchgear device can be shortened. In the arrangement structure of the bus sectioning units 3 and 4 as shown in Fig.1 through Fig.3 the arrangement structure including the circuit breakers 5 is formed substantially identically to that for the bus connecting units 14. Namely, when comparing Fig.2 which shows a side view of the bus sectioning unit 4 with Fig.4 which is a diagram taken along the line IV-IV in Fig.1 and shows a side view of the bus connecting unit 14, it is understood that the bus sectioning units 3 and 4 are constituted by adding a set of the PT 10 and the ES 12 to the bus connecting unit 14, thus the unit constitution thereof is simplified. These bus sectioning units 3 and 4 are disposed at the outer sides of their respective main buses while facing each other, however, the location of the branching bus 9 including the gas circuit breaker 5 and the branching bus 7 with no gas circuit breaker 5 in the bus sectioning unit 3 is inverted from that in the bus sectioning unit 4, namely the bus sectioning units 3 and 4 are disposed in rotation symmetry with respect to both the main buses. The importance thereof is explained hereinbelow. As seen from Fig.2, the main bus connected PT S 10 are disposed so as to project toward the space between the main buses 1 and 2 from the branching bus which is led out perpendicularly and upwardly from the respective main buses 1 and 2. Because of the disposition of the bus PT S 10 at the same height level as the facing main bus and of the rotation symmetry arrangement, the bus PT S 10 are arranged in the space between the main buses 1 and 2 in the axial direction thereof while displacing the locations thereof without enlarging the spacing distance between the main buses 1 and 2; the height of the entire arrangement structure of the bus sectioning units can also be limited. With regard to the main bus connected PT S 10 and the main bus use ES S 12 shown in Fig.1 and Fig.2, the bus PT S 10 make use of gas insulated wound type transformers and are disposed in the space between the two main buses 1 and 2, and the main bus use ES S 12 are disposed at the same height level as the bus PT S 10 but at the opposite side with respect to the connecting conductor. However, the arrangement structure with regard to their connecting position and direction is not limited to the present embodiment as will be understood from the following embodiments except that the bus PT 10 and the main bus use ES 12 are to be connected to the connecting conductor between the disconnecting switch 8a and the corresponding main bus. Accordingly, the positional relationship between the main bus connected PT 10 and the main bus use ES 12 as shown in Fig.2 can be inverted as shown in Fig.6. Similarly, the arrangement structure of the main bus connected PT 11 and the main bus use ES 13 with regard to their connecting position and direction as shown in Fig.3 is not specifically limited thereto except that the main bus connected PT 11 and the main bus use ES 13 are to be connected to the branching bus 7. Therefore, the main bus connected PT 11 can be disposed so as to hang down from the branching bus 7 into the space between the main bus 2 and the auxiliary bus 6' as shown in Fig.7, and contrary thereto the main bus connected PT 11 can be disposed so as to stand up on the branching bus 7 as shown in Fig.8. The arrangement structure as shown in Fig.7 improves the earthquake resistance because of the lowered center of gravity in comparison with those shown in Figs.3 and 8. Fig.5 is the entire arrangement structure of the bus sectioning units 3 and 4 when the main bus connected PT S 10 and 11 are disposed between each main bus 1, 2 and its respective auxiliary bus 6,6', as shown in Figs.6, 7 and 8, and as will be seen from the arrangement structure as shown in Fig.5, arranging the bus sectioning units 3 and 4 in rotation symmetry as has been explained above no longer brings any advantage; therefore the respective bus sectioning units 3 and 4 can be constituted as shown in Fig.9. Namely, the bus sectioning units 3 and 4 for the respective main buses 1 and 2 are arranged substantially in line symmetry with regard to the axial direction of the main buses 1 and 2. Because the main bus connected PT S and the main bus working use ES S are concentratedly arranged- in the respective bus sectioning units for the gas insulated switchgear device and the arrangement structure for the respective bus sectioning units is optimized, thereby the entire arrangement structure of the gas insulated switchgear device can be rationalized and compacted. Also the length of the main buses and the branching buses is shortened, which greatly improves the cost therefor.

Claims: A gas insulated switchgear device of a double bus type accommodated in a metal container filled with SF 6 gas and comprising first and second gas insulated main buses (1, 2) disposed horizontally in parallel with each other, a first bus sectioning unit (3) for sectioning said first main bus (1) into first and second main bus sections (1a, 1b) and including a first auxiliary bus (6) disposed outside said first main bus (1) in parallel with respective end portions of the first and second sections (1a, 1b) thereof, a first branching bus (9) connecting one of the respective end portions of the first and second sections (1a, 1b) of said first main bus (1) with one end of said first auxiliary bus (6) via a first vertical type circuit breaker (5) disposed outside said first auxiliary bus (6), and a second branching bus (7) connecting the other of the respective end portions of the first and second sections (1a, 1b) of said first main bus (1) with the other end of said first auxiliary bus (6) via no circuit breaker, and a second bus sectioning unit (4) for sectioning said second main bus (2) into first and second main bus sections (2a, 2b) and including a second auxiliary bus (6') disposed outside said second main bus (2) in parallel with respective end portions of the first and second sections (2a, 2b) thereof, a third branching bus (9) connecting one of the respective end portions of the first and second sections (2a, 2b) of said second main bus (2) with one end of said second auxiliary bus (6') via a second vertical type circuit breaker (5) disposed outside said second auxiliary bus (6'), and a fourth branching bus (7) connecting the other of the respective end portions of the first and second sections (2a, 2b) of said second main bus (2) with the other end of said second auxiliary bus (6') via no circuit breaker, characterised in that said first sectioning unit (3) includes a first main bus connected potential transformer (10) and a first main bus use earthing switch (12), each provided along said first branching bus (9), and a second main bus connected potential transformer (11) and a second main bus use earthing switch (13), each provided along said second branching bus (7), and said second sectioning unit (4) includes a third main bus connected potential transformer (10) and a third main bus use earthing switch (12), each provided along said third branching bus (9), and a fourth main bus connected potential transformer (11) and a fourth main bus use earthing switch (13), each provided along said fourth branching bus (7). The device of claim 1, wherein the elements in said second sectioning unit (4) are disposed in rotation symmetry with respect to those in said first sectioning unit (3). The device of claim 2, wherein said first and third main bus connected potential transformers (10) are disposed between said first and second main buses (1, 2). The device of claim 1, wherein the elements in said second sectioning unit (4) are disposed in axial symmetry with respect to those in said first sectioning unit (3) with reference to an axial line extending parallel with and between said first and second main buses (1, 2). The device of claim 2 or 4, wherein said first main bus connected potential transformer (10) is disposed between said first main bus (1) and said first auxiliary bus (6) and said third main bus connected potential transformer (10) is disposed between said second main bus (2) and said second auxiliary bus (6'). The device of any preceding claim, wherein said second and fourth main bus connected potential transformers (11) are provided in either upward or downward direction on the respective second and fourth branching buses (7). The device of any preceding claim, wherein said first and second main buses (1, 2) are of three-phase collective type, and said first, second, third and fourth branching buses (7, 9) are of phase isolated type.

Inventors: AOYAMA TAKANOBU, HACHIDA MASAKI, YAMAMOTO TADASUKE, YATSUZUKA HIROHIKO, AOYAMA, TAKANOBU, HACHIDA, MASAKI, YAMAMOTO, TADASUKE, YATSUZUKA, HIROHIKO
Applicants: HITACHI LTD, HITACHI, LTD.
Application year: 1995
Main classification: H02B5
IPC codes: H02B5, H02B13