Title of Invention	GAS-INSULATED SWITCHGEAR AND ASSEMBLY METHOD THEREOF
Abstract	1. A gas-insulated switchgear housing a main bus-bar conductor and accommodating a three-position disconnector switch/earthing switch, comprising; a disconnector switch fixed contact portion; an earthing switch fixed contact portion; a movable contactor supporting conductor disposed between both the contact portions; and a movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from both the contact portions, in a gas container to which insulation gas is filled, wherein one end portion of the main bus-bar conductor is fixed to a first insulation spacer while the other end portion is formed to be connect able to a detachable conductor, and in a center portion of the main bus-bar conductor, the disconnector switch fixed contact portion in a direction orthogonal to a longitudinal direction of the main bus-bar conductor is formed; wnerein the movable contactor supporting conductor is fixed by a second insulation spacer mounted to the gas container which is on an axis orthogonal to an axis of the first insulation spacer; wherein the earthing switch fixed contact portion is disposed behind the movable contactor as seen from the disconnector switch fixed contact portion; and wherein the detachable conductor is fixed by a third insulation spacer disposed in a position facing the first insulation spacer and is connected or separated to/from the other end portion of the main bus-bar conductor by moving forward or backward of the third insulation spacer in an internal direction of the gas container.

Title of Invention

GAS-INSULATED SWITCHGEAR AND ASSEMBLY METHOD THEREOF

Abstract

1. A gas-insulated switchgear housing a main bus-bar conductor and accommodating a three-position disconnector switch/earthing switch, comprising; a disconnector switch fixed contact portion; an earthing switch fixed contact portion; a movable contactor supporting conductor disposed between both the contact portions; and a movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from both the contact portions, in a gas container to which insulation gas is filled, wherein one end portion of the main bus-bar conductor is fixed to a first insulation spacer while the other end portion is formed to be connect able to a detachable conductor, and in a center portion of the main bus-bar conductor, the disconnector switch fixed contact portion in a direction orthogonal to a longitudinal direction of the main bus-bar conductor is formed; wnerein the movable contactor supporting conductor is fixed by a second insulation spacer mounted to the gas container which is on an axis orthogonal to an axis of the first insulation spacer; wherein the earthing switch fixed contact portion is disposed behind the movable contactor as seen from the disconnector switch fixed contact portion; and wherein the detachable conductor is fixed by a third insulation spacer disposed in a position facing the first insulation spacer and is connected or separated to/from the other end portion of the main bus-bar conductor by moving forward or backward of the third insulation spacer in an internal direction of the gas container.

Full Text	GAS-INSULATED SWITCHGEAR AND ASSEMBLY METHOD THEREOF CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2008-034781, filed on February 15th, 2008; the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION [ 0002 ] The present invention relates to a gas-insulated switchgear used in an electric power station such as a generating station or a substation, and in particular, relates to a gas-insulated switchgear in which a three-position disconnector switch/earthing switch having three positions of ON, OFF and grounding is miniaturized and an assembly property is improved, and an assembly method thereof. 2. DESCRIPTION OF THE RELATED ART [0003] In an electric power station such as a substation or a switching station which is established in a neighborhood of a large city or in a seaside district, as electric equipment constituting the substation or the switching station, there is used a gas-insulated switchgear housing openable/closable electric devices such as a circuit breaker and a disconnector switch in a container in which an insulating medium superior in an insulation property and an extinction property, such as SF6 gas, is filled and sealed, due to a reason of difficulty of land acquisition and measures against salt damage. [0004] In a gas-insulated switchgear, by three-dimensionally disposing a circuit breaker, a disconnector switch or other necessary devices, intervals between respective devices can be made narrower and a site area can be reduced. Accordingly, the gas-insulated switchgear can be constructed substantially smaller compared with an air-insulated switchgear. [0005] Further, electric devices are increasingly constructed in a building or in a basement in large cities, in consideration of environmental harmony between an electric power station and surrounding nature or residential zone. In the circumstances, development is promoted so that respective electric devices are rationally disposed to further reduce an installation area and volume. [0006] For example, in JP-A 2000-134733 (KOKAI) and JP-A 10-188746 (KOKAI), there are developed gas-insulated switchgears which are constructed so that one drive shaft each can drive a movable contactor common to a disconnector switch and an earthing switch, as examples to reduce installation areas and volumes. [0007] In the gas-insulated switchgear described in JP-A 2000-134733 (KOKAI), the common movable contactor which slides on and fittingly contacts fixed contact portions of the disconnector switch and the earthing switch that are housed in a gas container is disposed parallel in relation to a bus-bar conductor, and a portion of the bus-bar conductor facing the movable contactor is disposed to be substantially off-centered in relation to a center axis of the gas container. In other words, a center axis of the portion of the bus-bar conductor facing the movable contactor is disposed to be substantially off-centered in relation to the center axis of the gas container. [0008] Thus, in the gas-insulated switchgear described in JP-A 2000-134733 (KOKAI), an insulation spacer supporting the bus-bar conductor needs to be mounted in a manner to be substantially off-centered in relation to the center axis of the gas container. As a result, an outside diameter of the gas container is required to be larger compared with an outside diameter of the insulation spacer. [0009] The gas-insulated switchgear described in JP-A 10-188746 (KOKAI) is constructed so that the movable contactor is disposed with a predetermined angle in relation to an axis direction of the bus-bar conductor, not parallel to the axis direction of the bus-bar conductor. In such a construction, since an outer diameter of a main bus-bar portion of the gas container can be the same as an outer diameter of an insulation spacer, there is an advantage that the gas container can be constructed smaller compared with the gas-insulated switchgear described in JP-A 2000-134733 (KOKAI). However, the movable contactor and a fixed contactor of the disconnector switch or the earthing switch are not perpendicular in relation to a fixed conductor portion of the insulation spacer, and so an adjustment operation of centering at a time of assembling is difficult. [0010] It is also disclosed a gas-insulated switchgear in which movable contactors are independently provided for a disconnector switch and an earthing switch instead of a common movable contactor, and each movable contactor is driven by separate Geneva mechanisms, for example, in JP-A 11-355926 (KOKAI). [0011] The gas-insulated switchgear described in JP-A 11-355926 (KOKAI) has a position holding function to allow intermittent actions and to hold a movable contactor position, so that an assembly property is improved compared with the invention described in JP-A 2000-134733 (KOKAI). However, there is a disadvantage that an outer diameter of the gas container is larger compared with an outer diameter of an insulation spacer. [0012] As described above, in cases of the conventional gas-insulated switchgears described in JP-A 2000-134733 (KOKAI) and JP-A 11-355926 (KOKAI), there is a problem that miniaturization of the device is difficult since the outer diameters of the gas containers are required to be larger compared with the outer diameters of the insulation spacers. Meanwhile, in a case of the conventional gas-insulated switchgear described in JP-A 10-188746 (KOKAI), there is a problem that the assembly property is deteriorated when a disposition of devices in the container is altered in order to reduce the outer diameter of the gas container. BRIEF SUMMARY OF THE INVENTION [0013] In the circumstances, an object of the present invention is to provide a gas-insulated switchgear capable of miniaturizing a device and also improving an assembly property, and an assembly method thereof. [0014] According to an aspect of the present invention, there is provided a gas-insulated switchgear housing a main bus-bar conductor and accommodating a three-position disconnector switch/earthing switch including a disconnector switch fixed contact portion, an earthing switch fixed contact portion, a movable contactor supporting conductor disposed between both the contact portions, and a movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from both the contact portions, in a gas container to which insulation gas is filled, wherein one end portion of the main bus-bar conductor is fixed to a first insulation spacer while the other end portion is formed to be connectable to a detachable conductor, and in a center portion of the main bus-bar conductor, the disconnector switch fixed contact portion in a direction orthogonal to a longitudinal direction of the main bus-bar conductor is formed, wherein the movable contactor supporting conductor is fixed by a second insulation spacer mounted to the gas container which is on an axis orthogonal to an axis of the first insulation spacer, wherein the earthing switch fixed contact portion is disposed behind the movable contactor as seen from the disconnector switch fixed contact portion, and wherein the detachable conductor is fixed by a third insulation spacer disposed in a position facing the first insulation spacer and is connected or separated to/from the other end portion of the main bus-bar conductor by moving forward or backward of the third insulation spacer in an internal direction of the gas container. [0015] According to an aspect of the present invention, there is provided a gas-insulated switchgear housing a main bus-bar conductor and accommodating a three-position disconnector switch/earthing switch including a disconnector switch fixed contact portion, an earthing switch fixed contact portion, a movable contactor supporting conductor disposed between both the contact portions; and a movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from both the contact portions, in a gas container to which insulation gas is filled, wherein the gas container houses the main bus-bar conductor and has two facing openings in a longitudinal direction of the main bus-bar conductor and at least one opening in a direction almost orthogonal to the longitudinal direction of the main bus-bar conductor, wherein a disconnector switch fixed side unit is mounted to one of the two facing openings provided in the gas container, the disconnector switch fixed side unit having a first insulation spacer and the main bus-bar conductor whose one end is fixed to the first insulation spacer, in a center portion of the main bus-bar conductor, the disconnector switch fixed contact portion in a direction orthogonal to the longitudinal direction of the main bus-bar conductor being formed, and in the other end portion of the main bus-bar conductor a connection portion to another conductor being formed, wherein an earthing switch fixed side unit is mounted to a mounting surface side of the disconnector switch fixed side unit of the gas container, the earthing switch fixed side unit having the earthing switch fixed contact portion and an external lead-out terminal to connect the earthing switch fixed contact portion to the outside, wherein a movable contactor supporting unit is mounted to the opening provided in a direction almost orthogonal to the longitudinal direction of the main bus-bar conductor of the gas container, the movable contactor supporting unit having a second insulation spacer, the movable contactor supporting conductor fixed to the second insulation spacer and disposed to face the disconnector switch fixed contact portion, and the movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from either one of the disconnector switch fixed contact portion and the earthing switch fixed contact portion, and wherein a detachable unit is mounted to the other opening facing the disconnector switch fixed side unit of the gas container, the detachable unit having a third insulation spacer mounted to be able to move forward and backward in an internal direction of the gas container, and a detachable conductor fixed to the third insulation spacer and connectable or separatable to/from the connection portion formed in the other end portion of the main bus-bar conductor. [0016] Further, according to an aspect of the present invention, there is provided an assembly method of a gas-insulated switchgear having a gas container which accommodates a three-position disconnector switch/earthing switch constituted with amain bus-bar conductor, a disconnector switch fixed contact portion, an earthing switch fixed contact portion, a movable contactor supporting conductor disposed between both the contact portions, and a movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from both the contact portions, the gas container having two facing openings in a longitudinal direction of the main bus-bar conductor and at least one opening in a direction almost orthogonal to a longitudinal direction of the main bus-bar conductor, and insulation gas being filled to the gas container, the assembly method including a disconnector switch fixed side unit mounting in which a disconnector switch fixed side unit is mounted to one of two facing openings provided in the gas container, the disconnector switch fixed side unit having a first insulation spacer and a main bus-bar conductor whose one end is fixed to the first insulation spacer, in a center portion of the main bus-bar conductor, the disconnector switch fixed contact portion in a direction orthogonal to the longitudinal direction of the main bus-bar conductor being formed, and in the other end portion of the main bus-bar conductor a connection portion to another conductor being formed; an earthing switch fixed side unit mounting in which an earthing switch fixed side unit is mounted to a mounting surface side of the disconnector switch fixed side unit of the gas container, the earthing switch fixed side unit having the earthing switch fixed contact portion and an external lead-out terminal to connect the earthing switch fixed contact portion to the outside; a movable contactor supporting unit mounting in which a movable contactor supporting unit is mounted to the opening provided in the direction almost orthogonal to the longitudinal direction of the main bus-bar conductor of the gas container, the movable contactor supporting unit having a second insulation spacer, the movable contactor supporting conductor fixed to the second insulation spacer and disposed to face the disconnector switch fixed contact portion, and the movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from either one of the disconnector switch fixed contact portion and the earthing switch fixed contact portion; and a detachable unit mounting in which a detachable unit is mounted to the other opening facing the disconnector switch fixed side unit of the gas container, the detachable unit having a third insulation spacer mounted to be able to move forward and backward in an internal direction of the gas container and a detachable conductor fixed to the third insulation spacer and is connectable or separatable to/from the connection portion formed in the other end portion of the main bus-bar conductor. BRIEF DESCRIPTION OF THE DRAWINGS [0017] The present invention will be described with reference to the drawings, but those drawings are provided only for the purpose of illustration and are not intended to limit the invention in any- way. [0018] FIG. 1A is a view of a cross-section as seen from a side surface at a time that a disconnector switch and an earthing switch for gas-insulated switchgear according to the present invention are both in OFF positions. [0019] FIG. IB is a view of a cross-section as seen from a top surface at a time that the disconnector switch and the earthing switch for gas-insulated switchgear according to the present invention are both in OFF positions. [0020] FIG. 2 is a view of a cross-section as seen from a side surface at a time that the disconnector switch for gas-insulated switchgear according to the present invention is in an ON position and the earthing switch is in the OFF position. [0021] FIG. 3 is a view of a cross-section as seen from a side surface at a time that the disconnector switch for gas-insulated switchgear according to the present invention is in the OFF position and the earthing switch is in an ON position. [0022] FIG. 4 is an enlarged cross-sectional view showing an example of a detachable unit. DETAILED DESCRIPTION OF THE INVENTION [0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [0024] FIG. 1A to FIG. 4 are constructional views of a disconnector switch/earthing switch of a three-phase collective type gas-insulated switchgear according to the present invention. Among these, FIG. 1A and FIG. IB illustrate views of cross-sections as seen from a side surface and a top surface at a time that a disconnector switch and an earthing switch of the disconnector switch/earthing switch are both in OFF positions, respectively. FIG. 2 illustrates a view of a cross-section as seen from a side surface at a time that the disconnector switch is in an ON position and the earthing switch is in the OFF position, while FIG. 3 illustrates a view of a cross-section as seen from a side surface at a time that the disconnector switch is in the OFF position and the earthing switch is in an ON position. Further, FIG. 4 is a cross-sectional view showing, in enlargement, part of a detachable unit in FIG. 1A to FIG. 3. (Construction) [0025] First, a construction will be described with reference to FIG. 1A, FIG. IB and FIG. 4. A reference numeral "100" indicates an entire three position disconnector switch/earthing switch for gas insulated switchgear. [0026] A reference numeral "1" indicates a gas container housing a disconnector switch, a switch and other electric components therein and filling and sealing an insulating medium such as SF6 gas. As is shown in the drawing, openings la, lb, lc and Id are provided in upper and lower parts as well as right and left parts of the gas container respectively. Each of the openings la, lb, lc and Id can be sealed airtight by an insulation spacer or a cover, as will be described later. [0027] Among the openings of the gas container 1, to the opening la of the upper part, an insulation spacer 2a can be mounted airtight by a fixing means such as a bolt. One end portion of a main bus-bar conductor 3 of three-phase construction is fixed to the insulation spacer 2a in advance. Further, the main bus-bar conductor 3 is accommodated in the gas container 1 in a state that the insulation spacer 2a is mounted to the gas container 1. [0028] A fixed contact portion (hereinafter, referred to as a disconnector switch fixed contact portion) 4 of the disconnector switch is bored in a position of a center portion in a longitudinal direction of the main bus-bar contactor 3, the position also being perpendicular (right-angled) to an axis connecting the right and left openings 1c, 1d of the gas container 1. Alater-describedmovable contactor (hereinafter, referred to as a movable contactor) 5 used commonly by the disconnector switch and the earthing switch is disposed to be connectable or separatable to/from the disconnector switch fixed contact portion 4. It should be noted that in the present embodiment a portion enclosed by a dashed line, the portion being constituted with the insulation spacer 2a, the main bus-bar contactor 3 and the disconnector switch fixed contact portion 4, is referred to as a disconnector switch fixed side unit 6 for convenience sake. [0029 J Further, the other end portion, that is, a lower end portion 3T of the main bus-bar conductor 3 is constructed to be connectable or separatable to/from an upper end portion 7T of a detachable conductor 7 having been fixed in advance to an insulation spacer 2b fixed airtight to the opening lb of the lower part of the gas container 1. It should be noted that the detachable conductor 7 is a component of a detachable unit 8 which will be described later. [0030] Meanwhile, to the opening lc shown in a right side of the gas container 1, an insulation spacer 2c can be mounted airtight. To the insulation spacer 2c, there is fixed in advance a movable contactor supporting conductor 9 disposed with a predetermined insulation distance apart from the disconnector switch fixed contact portion 4 bored in the main bus-bar conductor 3. [0031 ] The movable contactor supporting conductor 9 is constructed to slidably store and support by a cylindrical portion the movable contactor 5 to be fitted to the disconnector switch fixed contact portion 4 and electrically connected thereto. It should be noted that in the present embodiment a portion enclosed by a dashed line, the portion being constituted with the insulation spacer 2c, the movable contactor 5 and the movable contactor supporting conductor 9, is referred to as a movable contactor supporting unit 10 for convenience sake, A center axis 11 of the insulation spacer 2c is disposed to be off-centered toward a side of the detachable unit 8 positioned in the lower part of the drawing as seen from a center axis of the gas container 1. [0032] In a space portion formed between the movable contactor supporting conductor 9 and the insulation spacer 2c in the gas container 1, that is, a space portion formed in a back side of the movable contactor 5 as seen from the disconnector switch fixed contact portion 4, there is disposed a fixed contact portion (hereinafter, referred to as an earthing switch fixed contact portion 13) of the earthing switch on the same axis as an axis between the disconnector switch fixed contact portion 4 and the movable contactor 5. £0033] An external lead-out terminal 14 doubles as a supporting member of the earthing switch fixed contact portion 13 is mounted to a mounting surface being a surface flat with the opening la of the gas container 1. The earthing switch fixed contact portion 13 is to be grounded via the external lead-out terminal 14 doubling the supporting member. It should be noted that in the present embodiment a portion enclosed by a dashed line, the portion being constituted with the earthing switch fixed contact portion 13 and the external lead-out terminal 14, is referred to as an earthing switch fixed side unit 15 for convenience sake. [0034] For example, by converting a rotary movement of a driving shaft 16 to a linear movement with a rack-and-pinion steering, a linkage lever or the like, the movable contactor 5 is linearly driven to be connected or separated to/from the disconnector switch fixed contact portion 4 and the earthing switch fixed contact portion 13. (0035] A reference numeral "21" shown in FIG. IB indicates an operational device to rotate-drive the driving shaft 16 via an insulation rod 22. h reference numeral "17" indicates an inspection cover to airtightly seal the opening Id of a left side of the gas container 1. [0036] Next, the detachable unit 8 will be described with reference to FIG. 4.The detachable unit 8 is a unit to connect or separate an upper end portion 7T of the detachable conductor 7 to/from the lower end portion 3T of the main bus-bar conductor 3. The detachable unit 8 is constituted with components described below. [0037] The detachable unit 8 is constituted with an insulation spacer 2b, the detachable conductor 7 of each phase of three phases each having been fixed in advance to a predetermined position of the insulation spacer 2b, and a cylinder 19 which has a flange 19F fixed by a bolt 18 to a metal mounting ring 2br provided in an outer periphery portion of the insulation spacer 2b and which is airtightly and slidably fitted to an inner periphery portion of the opening lb of the lower part of the gas container 1 via a seal member, and an attaching/detaching means 20 provided between the flange 19F of the cylinder 19 and a container flange IF formed around the opening lb of the lower part of the gas container. [0038] The attaching/detaching means 20 is constituted with a stud 20s having one end portion of which is screwed to a lower surface of the container flange IF, a nut 20nl fixing the stud 20s in a state being upright in a forward and backward direction of the cylinder 19, and nuts 20n2, 20n3 disposed on both sides of a through hole opened in the flange 19F of the cylinder 19 and screwed with the stud 20s. As for the attaching/detaching means 20, when the nut 20n3 is screwed forward in a state that the nut 20n2 is loosened, the detachable conductor 7 moves toward the lower end portion 3T of the main bus-bar conductor 3 together with the cylinder 19 and the insulation spacer 2b. Then, the detachable conductor 7 is connected to the lower end portion 3T of the main bus-bar conductor 3 eventually. When the nut 20n2 is fastened in such a state and pressed hard to the flange 19F, a connected state between the main bus-bar conductor 3 and the detachable conductor 7 is maintained. [0039] Next, assembly of the three-position disconnector switch/earthing switch 100 and an operation of the three-position disconnector switch/earthing switch will be described with reference to FIG. 1A to FIG. 4. (1) Assembling Process [0040] (i) First, the insulation spacer 2a of the disconnector switch fixed side unit 6 is mounted airtight to the opening la of i the upper part of the gas container la, whereby the main bus-bar conductor 3 in which the disconnector switch fixed contact portion 4 is bored is housed in the gas container 1. [0041] (ii) Next, the earthing switch fixed side unit 15 is mounted airtight to the mounting surface being the surface flat with the opening la of upper part of the gas container 1, whereby the earthing switch fixed contact portion 13 provided in a tip portion of the earthing switch fixed side unit 15 is housed in the gas container (ii) can precede the other. [0042] (iii) Thereafter, the insulation spacer 2c of the movable contactor supporting unit 10 is mounted to the opening lc of the right side part of the gas container 1, whereby the movable contactor 5 supported by the movable contactor supporting conductor 9 is disposed between the disconnector switch fixed contact portion 4 and the earthing switch fixed side unit 15 with predetermined insulation distances apart each. [0043] (iv) At a stage that the above-described process (iii) is finished, the detachable unit 8 is not mounted to the opening lb of the lower part of the gas container 1 yet. Thus, a state inside the gas container 1 can be seen from the opening lb of the lower part and a jig can also be inserted. [0044] Thus, after the process (iii) is finished, a centering adjustment operation is performed by the jig or viewing from the opening lb of the lower part so that axes of the disconnector switch fixed contact portion 4, the movable contactor 5 and the earthing switch fixed contact portion 13 are disposed in alignment with one another. [0045] (v) After the operation of centering adjustment in the above-described process (iv), the detachable unit 8 is mounted to the lower part of the gas container 1 and an upper terminal of the detachable conductor 7 is connected to a lower terminal of the main bus-bar conductor 3. In the above operation, first, the cylinder 19 is fitted to the opening lb of the lower part of the gas container 1. Then, while the stud 20s fixed to be upright around the opening lb of the lower part is in a state of being through the through hole provided in the flange 19F of the cylinder 19, the nut 20n2 is loosen. Subsequently, the nut 20n3 is turned in a screw forward direction, whereby the cylinder 19 is pushed up from below and the detachable conductor 7 fixed to the insulation spacer 2b is pushed forward in an internal direction of the gas container 1. [0046] Then, when the upper end portion 7T of the detachable conductor 7 becomes in a state of being connected to the lower end portion 3T of the main bus-bar conductor 3 with an adequate pressure, the nut 20n2 is turned in a reverse direction to strongly press the stud 20s to the flange 19F, so that a fixed state of the detachable unit 8 to the gas container lower part is maintained. Hereby, the assembly of the three-position disconnector switch/earthing switch 100 of the gas-insulated switchgear is completed. (2) Operation of Three-position Disconnector Switch/Earthing Switch [0047] FIG. 1A shows a state that the three-position disconnector switch/earthing switch is in the OFF state. In other words, the movable contactor 5 is housed in the movable contactor supporting conductor 9 of the movable contactor supporting unit 10, and in a state of not being connected to either the disconnector switch fixed contact portion 4 or the earthing switch fixed contact portion 13, that is, in a state of "disconnector switch OFF" and "earthing switch OFF". [0048] In the above state, when the operational device 21 is operated for "disconnector switch ON" by a motor action by remote control or a direct handle operation, a rotational force from the operational device 21 is transmitted to a converting means converting a rotary movement of a rack-and-pinion steering, a linkage lever or the like to a linear movement, via the insulation rod 22 and the driving shaft 16 in the gas container 1. Then, by this converting means, the rotary movement is converted to the linear movement and a driving force is transmitted to the three-phase movable contactor 5. [ 0049] By the above driving force, the movable contactor 5 is moved from the position in FIG. 1A to a main bus-bar conductor 3 side and stops at a position in FIG. 2, in which the movable contactor 5 is connected to the disconnector switch fixed contact portion 4. A state in FIG. 2 is a state of "disconnector switch ON" and "earthing switch OFF". [ 0050 ] On the other hand, when the operational device 21 is operated for "earthing switch ON", the movable contactor 5 is moved to the opposite side of the main bus-bar conductor 2, that is, to an earthing switch fixed contactor 13 side, and stops at a position in FIG. 3, in which the movable contactor 5 is connected to the earthing switch l fixed contact portion 13. A state in FIG. 3 is a state of "disconnector switch OFF" and "earthing switch ON". (Effect) [0051] As described above, according to the present embodiment, effects described below can be attained. 5 [0052] (i) The movable contactor 5 used by both the disconnector switch and the earthing switch is disposed to be almost orthogonal to the main bus-bar conductor 3 and the earthing switch fixed contact portion 13 is disposed behind the movable contactor 5 in a manner that the axes of the movable contactor 5 and the earthing switch fixed contact portion 13 become aligned as seen from the disconnector switch fixed contact portion 4, and there is disposed the detachable unit 8 having the detachable conductor 7 to be connected or separated to/from the lower end portion 3T of the main bus-bar conductor 3, and further, the center axis 11 of the insulation spacer 2c of the movable contactor supporting unit 10 supporting the movable contactor 5 is disposed to be off-centered toward the detachable unit 8 side as seen from the center axis 12 of the gas container 1. As a result, miniaturization and the assembly property of the three-position disconnector switch/earthing switch can be improved. [0053] (ii) Further, it is constructed so that the movable contactor supporting unit 10 is inserted to the gas container 1 and assembled after the disconnector switch fixed side unit 6 and the earthing switch fixed side unit 15 are assembled in the gas container 1. As a result, it is possible to improve the centering adjustment operation to dispose the axes of the disconnector switch fixed side unit 6, the earthing switch fixed side unit 15 and the movable contactor 5 aligned with one another from the opening lb of the lower part of the gas container 1. [0054] (iii) Further, it is disposed so that the mounting surface of the disconnector switch fixed side unit 6 of the gas container 1 and the mounting surface of the earthing switch fixed side unit 15 of the gas container 1 become the same mounting surface. As a result, it is possible to improve the centering adjustment operation to dispose the disconnector switch fixed side unit 6, the earthing switch fixed side unit 15 and the movable contactor 5 aligned with one another. It should be noted even if there is a level difference between the mounting surface of the disconnector switch fixed side unit 6 and the mounting surface of the earthing switch fixed side unit 15, a similar effect can be attained as long as both the mounting surfaces are almost parallel to each other. [0055] (iv) Furthermore, since the detachable unit 8 is disposed in the opposite side of the earthing switch fixed side unit 15, the earthing switch fixed side unit 15 is not in a neighborhood. As a result a local assembling space of the detachable unit 8 side can be secured, improving the assembling property. [0056] (v) Since the opening lb of the gas container 1, the opening lb being the mounting surface of the detachable unit 8, is used at a time of internal assembling, it is not required to provide the gas container 1 with an unnecessary assembling hole. Therefore, it becomes possible to construct the gas container 1 without reducing strength of the container 1. Thereby, reliability of the device is improved and the centering adjustment operation of the three-position disconnector switch/earthing switch 100 by a jig or viewing can be improved. [0057] Further, a structure is adopted that the detachable conductor 7 is slidably fit to the gas container 1 via the insulation spacer 2b and the cylinder 19 to seal the gas. As a result, in intercircuit unit connection at a local mounting location of the gas-insulated switchgear, a connection operation to other equipment can be easily done by extending/retracting the detachable conductor 7 in the longitudinal direction of the main bus-bar conductor 3. [0058] (vi) Further, since it is constructed so that an operational ground terminal is drew out per phase, an effect of improved workability at a time of inspection of the gas-insulated switchgear can be also attained in a three-position disconnector switch/earthing switch 100 which is constituted small-sized. WHAT IS CLAIMED IS: 1. A gas-insulated switchgear housing a main bus-bar conductor and accommodating a three-position disconnector switch/earthing switch, comprising; a disconnector switch fixed contact portion; an earthing switch fixed contact portion; a movable contactor supporting conductor disposed between both the contact portions; and a movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from both the contact portions, in a gas container to which insulation gas is filled, wherein one end portion of the main bus-bar conductor is fixed to a first insulation spacer while the other end portion is formed to be connect able to a detachable conductor, and in a center portion of the main bus-bar conductor, the disconnector switch fixed contact portion in a direction orthogonal to a longitudinal direction of the main bus-bar conductor is formed; wnerein the movable contactor supporting conductor is fixed by a second insulation spacer mounted to the gas container which is on an axis orthogonal to an axis of the first insulation spacer; wherein the earthing switch fixed contact portion is disposed behind the movable contactor as seen from the disconnector switch fixed contact portion; and wherein the detachable conductor is fixed by a third insulation spacer disposed in a position facing the first insulation spacer and is connected or separated to/from the other end portion of the main bus-bar conductor by moving forward or backward of the third insulation spacer in an internal direction of the gas container. 2. A gas-insulated switchgear housing a main bus-bar conductor and accommodating a three-position disconnector switch/earthing switch, comprising; a disconnector switch fixed contact portion; an earthing switch fixed contact portion; a movable contactor supporting conductor disposed between both the contact portions; and a movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from both the contact portions, in a gas container to which insulation gas is filled, wherein the gas container houses the main bus-bar conductor and has two facing openings in a longitudinal direction of the main bus-bar conductor and at least one opening in a direction almost orthogonal to the longitudinal direction of the main bus-bar conductor; wherein a disconnector switch fixed side unit is mounted to one of the two facing openings provided in the gas container, the disconnector switch fixed side unit having a first insulation spacer and the main bus-bar conductor whose one end is fixed to the first insulation spacer, in a center portion of the main bus-bar conductor, the disconnector switch fixed contact portion in a direction orthogonal to the longitudinal direction of the main bus-bar conductor being formed, and in the other end portion of the main bus-bar conductor a connection portion to another conductor being formed; wherein an earthing switch fixed side unit is mounted to a mounting surface side of the disconnector switch fixed side unit of the gas container, the earthing switch fixed side unit having the earthing switch fixed contact portion and an external lead-out terminal to connect the earthing switch fixed contact portion to the outside; wherein a movable contactor supporting unit is mounted to the opening provided in a direction almost orthogonal to the longitudinal direction of the main bus-bar conductor of the gas container, the movable contactor supporting unit having a second insulation spacer, the movable contactor supporting conductor fixed to the second insulation spacer and disposed to face the disconnector switch fixed contact portion, and the movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from either one of the disconnector switch fixed contact portion and the earthing switch fixed contact portion; and wherein a detachable unit is mounted to the other opening facing the disconnector switch fixed side unit of the gas container, the detachable unit having a third insulation spacer mounted to be able to move forward and backward in an internal direction of the gas container, and a detachable conductor fixed to the third insulation spacer and connectable or separatable to/from the connection portion formed in the other end portion of the main bus-bar conductor. 3. The gas-insulated switchgear as set forth in claim 2, wherein a mounting surface of the disconnector switch fixed side unit to the gas container and a mounting surface of the earthing switch fixed side unit to the gas container are the same mounting surface or parallel mounting surfaces. 4. The gas-insulated switchgear as set forth in claim 2, wherein the detachable unit is disposed on the opposite side of the earthing switch fixed side unit. 5. The gas-insulated switchgear as set forth in claim 2, wherein a center axis of the second insulation spacer constituting the movable contactor supporting unit is disposed to be off-centered toward a side of a detachable unit as seen from a center axis of the gas container. 6. The gas-insulated switchgear as set froth in claim 2, wherein the external lead-out terminal is lead out per each phase. 7. An assembly method of a gas-insulated switchgear having a gas container which accommodates a three-position disconnector switch/earthing switch constituted with a main bus-bar conductor, a disconnector switch fixed contact portion, an earthing switch fixed contact portion, a movable contactor supporting conductor disposed between both the contact portions, and a movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from both the contact portions, the gas container having two facing openings in a longitudinal direction of the main bus-bar conductor and at least one opening in a direction almost orthogonal to a longitudinal direction of the main bus-bar conductor, and insulation gas being filled to the gas container, the assembly method, comprising: a disconnector switch fixed side unit mounting in which a disconnector switch fixed side unit is mounted to one of two facing openings provided in the gas container, the disconnector switch fixed side unit having a first insulation spacer and amain bus-bar conductor whose one end is fixed to the first insulation spacer, in a center portion of the main bus-bar conductor, the disconnector switch fixed contact portion in a direction orthogonal to the longitudinal direction of the main bus-bar conductor being formed, and in the other end portion of the main bus-bar conductor a connection portion to another conductor being formed; an earthing switch fixed side unit mounting in which an earthing switch fixed side unit is mounted to a mounting surface side of the disconnector switch fixed side unit of the gas container, the earthing switch fixed side unit having the earthing switch fixed contact portion and an external lead-out terminal to connect the earthing switch fixed contact portion to the outside; amovable contactor supporting unit mounting in which amovable contactor supporting unit is mounted to the opening provided in the direction almost orthogonal to the longitudinal direction of the main bus-bar conductor of the gas container, the movable contactor supporting unit having a second insulation spacer, the movable contactor supporting conductor fixed to the second insulation spacer and disposed to face the disconnector switch fixed contact portion, and the movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from either one of the disconnector switch fixed contact portion and the earthing switch fixed contact portion,* and a detachable unitmounting in which adetachable unit is mounted to the other opening facing the disconnector switch fixed side unit of the gas container, the detachable unit having a third insulation spacer mounted to be able to move forward and backward in an internal direction of the gas container and a detachable conductor fixed to the third insulation spacer and is connectable or separatable to/from the connection portion formed in the other end portion of the main bus-bar conductor. 8. The assembly method of the gas-insulated switchgear as set forth in claim 7, wherein, in the movable contactor supporting unit mounting, a drive mechanism of the movable contactor is assembled by using the opening of the gas container of amounting surface of the detachable unit. 9. The assembly method of the gas-insulated switchgear as set forth in claim 7, wherein, in the movable contactor supporting unit mounting after the disconnector switch fixed side unit mounting and the earthing switch fixed side unit mounting, the movable contactor supporting unit is mounted to the gas container and a centering adjustment operation of axes of the disconnector switch fixed contact portion, the earthing switch fixed contact portion and the movable contactor is performed. 1. A gas-insulated switchgear housing a main bus-bar conductor and accommodating a three-position disconnector switch/earthing switch, comprising; a disconnector switch fixed contact portion; an earthing switch fixed contact portion; a movable contactor supporting conductor disposed between both the contact portions; and a movable contactor slidably supported by the movable contactor supporting conductor to be connected or separated to/from both the contact portions, in a gas container to which insulation gas is filled, wherein one end portion of the main bus-bar conductor is fixed to a first insulation spacer while the other end portion is formed to be connect able to a detachable conductor, and in a center portion of the main bus-bar conductor, the disconnector switch fixed contact portion in a direction orthogonal to a longitudinal direction of the main bus-bar conductor is formed; wnerein the movable contactor supporting conductor is fixed by a second insulation spacer mounted to the gas container which is on an axis orthogonal to an axis of the first insulation spacer; wherein the earthing switch fixed contact portion is disposed behind the movable contactor as seen from the disconnector switch fixed contact portion; and wherein the detachable conductor is fixed by a third insulation spacer disposed in a position facing the first insulation spacer and is connected or separated to/from the other end portion of the main bus-bar conductor by moving forward or backward of the third insulation spacer in an internal direction of the gas container.

Full Text

GAS-INSULATED SWITCHGEAR AND ASSEMBLY METHOD THEREOF
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No. 2008-034781,
filed on February 15th, 2008; the entire contents of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
[ 0002 ] The present invention relates to a gas-insulated switchgear
used in an electric power station such as a generating station or
a substation, and in particular, relates to a gas-insulated switchgear
in which a three-position disconnector switch/earthing switch having
three positions of ON, OFF and grounding is miniaturized and an
assembly property is improved, and an assembly method thereof.
2. DESCRIPTION OF THE RELATED ART
[0003] In an electric power station such as a substation or a
switching station which is established in a neighborhood of a large
city or in a seaside district, as electric equipment constituting
the substation or the switching station, there is used a gas-insulated
switchgear housing openable/closable electric devices such as a
circuit breaker and a disconnector switch in a container in which
an insulating medium superior in an insulation property and an
extinction property, such as SF6 gas, is filled and sealed, due to
a reason of difficulty of land acquisition and measures against salt
damage.
[0004] In a gas-insulated switchgear, by three-dimensionally

disposing a circuit breaker, a disconnector switch or other necessary
devices, intervals between respective devices can be made narrower
and a site area can be reduced. Accordingly, the gas-insulated
switchgear can be constructed substantially smaller compared with
an air-insulated switchgear.
[0005] Further, electric devices are increasingly constructed in
a building or in a basement in large cities, in consideration of
environmental harmony between an electric power station and
surrounding nature or residential zone. In the circumstances,
development is promoted so that respective electric devices are
rationally disposed to further reduce an installation area and volume.
[0006] For example, in JP-A 2000-134733 (KOKAI) and JP-A 10-188746
(KOKAI), there are developed gas-insulated switchgears which are
constructed so that one drive shaft each can drive a movable contactor
common to a disconnector switch and an earthing switch, as examples
to reduce installation areas and volumes.
[0007] In the gas-insulated switchgear described in JP-A
2000-134733 (KOKAI), the common movable contactor which slides on
and fittingly contacts fixed contact portions of the disconnector
switch and the earthing switch that are housed in a gas container
is disposed parallel in relation to a bus-bar conductor, and a portion
of the bus-bar conductor facing the movable contactor is disposed
to be substantially off-centered in relation to a center axis of
the gas container. In other words, a center axis of the portion
of the bus-bar conductor facing the movable contactor is disposed
to be substantially off-centered in relation to the center axis of
the gas container.
[0008] Thus, in the gas-insulated switchgear described in JP-A

2000-134733 (KOKAI), an insulation spacer supporting the bus-bar
conductor needs to be mounted in a manner to be substantially
off-centered in relation to the center axis of the gas container.
As a result, an outside diameter of the gas container is required
to be larger compared with an outside diameter of the insulation
spacer.
[0009] The gas-insulated switchgear described in JP-A 10-188746
(KOKAI) is constructed so that the movable contactor is disposed
with a predetermined angle in relation to an axis direction of the
bus-bar conductor, not parallel to the axis direction of the bus-bar
conductor. In such a construction, since an outer diameter of a
main bus-bar portion of the gas container can be the same as an outer
diameter of an insulation spacer, there is an advantage that the
gas container can be constructed smaller compared with the
gas-insulated switchgear described in JP-A 2000-134733 (KOKAI).
However, the movable contactor and a fixed contactor of the
disconnector switch or the earthing switch are not perpendicular
in relation to a fixed conductor portion of the insulation spacer,
and so an adjustment operation of centering at a time of assembling
is difficult.
[0010] It is also disclosed a gas-insulated switchgear in which
movable contactors are independently provided for a disconnector
switch and an earthing switch instead of a common movable contactor,
and each movable contactor is driven by separate Geneva mechanisms,
for example, in JP-A 11-355926 (KOKAI).
[0011] The gas-insulated switchgear described in JP-A 11-355926
(KOKAI) has a position holding function to allow intermittent actions
and to hold a movable contactor position, so that an assembly property

is improved compared with the invention described in JP-A 2000-134733
(KOKAI). However, there is a disadvantage that an outer diameter
of the gas container is larger compared with an outer diameter of
an insulation spacer.
[0012] As described above, in cases of the conventional
gas-insulated switchgears described in JP-A 2000-134733 (KOKAI)
and JP-A 11-355926 (KOKAI), there is a problem that miniaturization
of the device is difficult since the outer diameters of the gas
containers are required to be larger compared with the outer diameters
of the insulation spacers. Meanwhile, in a case of the conventional
gas-insulated switchgear described in JP-A 10-188746 (KOKAI), there
is a problem that the assembly property is deteriorated when a
disposition of devices in the container is altered in order to reduce
the outer diameter of the gas container.
BRIEF SUMMARY OF THE INVENTION
[0013] In the circumstances, an object of the present invention
is to provide a gas-insulated switchgear capable of miniaturizing
a device and also improving an assembly property, and an assembly
method thereof.
[0014] According to an aspect of the present invention, there is
provided a gas-insulated switchgear housing a main bus-bar conductor
and accommodating a three-position disconnector switch/earthing
switch including a disconnector switch fixed contact portion, an
earthing switch fixed contact portion, a movable contactor supporting
conductor disposed between both the contact portions, and a movable
contactor slidably supported by the movable contactor supporting
conductor to be connected or separated to/from both the contact

portions, in a gas container to which insulation gas is filled, wherein
one end portion of the main bus-bar conductor is fixed to a first
insulation spacer while the other end portion is formed to be
connectable to a detachable conductor, and in a center portion of
the main bus-bar conductor, the disconnector switch fixed contact
portion in a direction orthogonal to a longitudinal direction of
the main bus-bar conductor is formed, wherein the movable contactor
supporting conductor is fixed by a second insulation spacer mounted
to the gas container which is on an axis orthogonal to an axis of
the first insulation spacer, wherein the earthing switch fixed contact
portion is disposed behind the movable contactor as seen from the
disconnector switch fixed contact portion, and wherein the detachable
conductor is fixed by a third insulation spacer disposed in a position
facing the first insulation spacer and is connected or separated
to/from the other end portion of the main bus-bar conductor by moving
forward or backward of the third insulation spacer in an internal
direction of the gas container.
[0015] According to an aspect of the present invention, there is
provided a gas-insulated switchgear housing a main bus-bar conductor
and accommodating a three-position disconnector switch/earthing
switch including a disconnector switch fixed contact portion, an
earthing switch fixed contact portion, a movable contactor supporting
conductor disposed between both the contact portions; and a movable
contactor slidably supported by the movable contactor supporting
conductor to be connected or separated to/from both the contact
portions, in a gas container to which insulation gas is filled, wherein
the gas container houses the main bus-bar conductor and has two facing
openings in a longitudinal direction of the main bus-bar conductor

and at least one opening in a direction almost orthogonal to the
longitudinal direction of the main bus-bar conductor, wherein a
disconnector switch fixed side unit is mounted to one of the two
facing openings provided in the gas container, the disconnector switch
fixed side unit having a first insulation spacer and the main bus-bar
conductor whose one end is fixed to the first insulation spacer,
in a center portion of the main bus-bar conductor, the disconnector
switch fixed contact portion in a direction orthogonal to the
longitudinal direction of the main bus-bar conductor being formed,
and in the other end portion of the main bus-bar conductor a connection
portion to another conductor being formed, wherein an earthing switch
fixed side unit is mounted to a mounting surface side of the
disconnector switch fixed side unit of the gas container, the earthing
switch fixed side unit having the earthing switch fixed contact
portion and an external lead-out terminal to connect the earthing
switch fixed contact portion to the outside, wherein a movable
contactor supporting unit is mounted to the opening provided in a
direction almost orthogonal to the longitudinal direction of the
main bus-bar conductor of the gas container, the movable contactor
supporting unit having a second insulation spacer, the movable
contactor supporting conductor fixed to the second insulation spacer
and disposed to face the disconnector switch fixed contact portion,
and the movable contactor slidably supported by the movable contactor
supporting conductor to be connected or separated to/from either
one of the disconnector switch fixed contact portion and the earthing
switch fixed contact portion, and wherein a detachable unit is mounted
to the other opening facing the disconnector switch fixed side unit
of the gas container, the detachable unit having a third insulation

spacer mounted to be able to move forward and backward in an internal
direction of the gas container, and a detachable conductor fixed
to the third insulation spacer and connectable or separatable to/from
the connection portion formed in the other end portion of the main
bus-bar conductor.
[0016] Further, according to an aspect of the present invention,
there is provided an assembly method of a gas-insulated switchgear
having a gas container which accommodates a three-position
disconnector switch/earthing switch constituted with amain bus-bar
conductor, a disconnector switch fixed contact portion, an earthing
switch fixed contact portion, a movable contactor supporting
conductor disposed between both the contact portions, and a movable
contactor slidably supported by the movable contactor supporting
conductor to be connected or separated to/from both the contact
portions, the gas container having two facing openings in a
longitudinal direction of the main bus-bar conductor and at least
one opening in a direction almost orthogonal to a longitudinal
direction of the main bus-bar conductor, and insulation gas being
filled to the gas container, the assembly method including a
disconnector switch fixed side unit mounting in which a disconnector
switch fixed side unit is mounted to one of two facing openings provided
in the gas container, the disconnector switch fixed side unit having
a first insulation spacer and a main bus-bar conductor whose one
end is fixed to the first insulation spacer, in a center portion
of the main bus-bar conductor, the disconnector switch fixed contact
portion in a direction orthogonal to the longitudinal direction of
the main bus-bar conductor being formed, and in the other end portion
of the main bus-bar conductor a connection portion to another

conductor being formed; an earthing switch fixed side unit mounting
in which an earthing switch fixed side unit is mounted to a mounting
surface side of the disconnector switch fixed side unit of the gas
container, the earthing switch fixed side unit having the earthing
switch fixed contact portion and an external lead-out terminal to
connect the earthing switch fixed contact portion to the outside;
a movable contactor supporting unit mounting in which a movable
contactor supporting unit is mounted to the opening provided in the
direction almost orthogonal to the longitudinal direction of the
main bus-bar conductor of the gas container, the movable contactor
supporting unit having a second insulation spacer, the movable
contactor supporting conductor fixed to the second insulation spacer
and disposed to face the disconnector switch fixed contact portion,
and the movable contactor slidably supported by the movable contactor
supporting conductor to be connected or separated to/from either
one of the disconnector switch fixed contact portion and the earthing
switch fixed contact portion; and a detachable unit mounting in which
a detachable unit is mounted to the other opening facing the
disconnector switch fixed side unit of the gas container, the
detachable unit having a third insulation spacer mounted to be able
to move forward and backward in an internal direction of the gas
container and a detachable conductor fixed to the third insulation
spacer and is connectable or separatable to/from the connection
portion formed in the other end portion of the main bus-bar conductor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be described with reference to
the drawings, but those drawings are provided only for the purpose

of illustration and are not intended to limit the invention in any-
way.
[0018] FIG. 1A is a view of a cross-section as seen from a side
surface at a time that a disconnector switch and an earthing switch
for gas-insulated switchgear according to the present invention are
both in OFF positions.
[0019] FIG. IB is a view of a cross-section as seen from a top
surface at a time that the disconnector switch and the earthing switch
for gas-insulated switchgear according to the present invention are
both in OFF positions.
[0020] FIG. 2 is a view of a cross-section as seen from a side
surface at a time that the disconnector switch for gas-insulated
switchgear according to the present invention is in an ON position
and the earthing switch is in the OFF position.
[0021] FIG. 3 is a view of a cross-section as seen from a side
surface at a time that the disconnector switch for gas-insulated
switchgear according to the present invention is in the OFF position
and the earthing switch is in an ON position.
[0022] FIG. 4 is an enlarged cross-sectional view showing an
example of a detachable unit.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Hereinafter, an embodiment of the present invention will
be described with reference to the drawings.
[0024] FIG. 1A to FIG. 4 are constructional views of a disconnector
switch/earthing switch of a three-phase collective type
gas-insulated switchgear according to the present invention. Among
these, FIG. 1A and FIG. IB illustrate views of cross-sections as

seen from a side surface and a top surface at a time that a disconnector
switch and an earthing switch of the disconnector switch/earthing
switch are both in OFF positions, respectively. FIG. 2 illustrates
a view of a cross-section as seen from a side surface at a time that
the disconnector switch is in an ON position and the earthing switch
is in the OFF position, while FIG. 3 illustrates a view of a
cross-section as seen from a side surface at a time that the
disconnector switch is in the OFF position and the earthing switch
is in an ON position. Further, FIG. 4 is a cross-sectional view
showing, in enlargement, part of a detachable unit in FIG. 1A to
FIG. 3.
(Construction)
[0025] First, a construction will be described with reference to
FIG. 1A, FIG. IB and FIG. 4. A reference numeral "100" indicates
an entire three position disconnector switch/earthing switch for
gas insulated switchgear.
[0026] A reference numeral "1" indicates a gas container housing
a disconnector switch, a switch and other electric components therein
and filling and sealing an insulating medium such as SF6 gas. As
is shown in the drawing, openings la, lb, lc and Id are provided
in upper and lower parts as well as right and left parts of the gas
container respectively. Each of the openings la, lb, lc and Id can
be sealed airtight by an insulation spacer or a cover, as will be
described later.
[0027] Among the openings of the gas container 1, to the opening
la of the upper part, an insulation spacer 2a can be mounted airtight
by a fixing means such as a bolt. One end portion of a main bus-bar
conductor 3 of three-phase construction is fixed to the insulation

spacer 2a in advance. Further, the main bus-bar conductor 3 is
accommodated in the gas container 1 in a state that the insulation
spacer 2a is mounted to the gas container 1.
[0028] A fixed contact portion (hereinafter, referred to as a
disconnector switch fixed contact portion) 4 of the disconnector
switch is bored in a position of a center portion in a longitudinal
direction of the main bus-bar contactor 3, the position also being
perpendicular (right-angled) to an axis connecting the right and
left openings 1c, 1d of the gas container 1. Alater-describedmovable
contactor (hereinafter, referred to as a movable contactor) 5 used
commonly by the disconnector switch and the earthing switch is
disposed to be connectable or separatable to/from the disconnector
switch fixed contact portion 4. It should be noted that in the present
embodiment a portion enclosed by a dashed line, the portion being
constituted with the insulation spacer 2a, the main bus-bar contactor
3 and the disconnector switch fixed contact portion 4, is referred
to as a disconnector switch fixed side unit 6 for convenience sake.
[0029 J Further, the other end portion, that is, a lower end portion
3T of the main bus-bar conductor 3 is constructed to be connectable
or separatable to/from an upper end portion 7T of a detachable
conductor 7 having been fixed in advance to an insulation spacer
2b fixed airtight to the opening lb of the lower part of the gas
container 1. It should be noted that the detachable conductor 7
is a component of a detachable unit 8 which will be described later.
[0030] Meanwhile, to the opening lc shown in a right side of the
gas container 1, an insulation spacer 2c can be mounted airtight.
To the insulation spacer 2c, there is fixed in advance a movable
contactor supporting conductor 9 disposed with a predetermined

insulation distance apart from the disconnector switch fixed contact
portion 4 bored in the main bus-bar conductor 3.
[0031 ] The movable contactor supporting conductor 9 is constructed
to slidably store and support by a cylindrical portion the movable
contactor 5 to be fitted to the disconnector switch fixed contact
portion 4 and electrically connected thereto. It should be noted
that in the present embodiment a portion enclosed by a dashed line,
the portion being constituted with the insulation spacer 2c, the
movable contactor 5 and the movable contactor supporting conductor
9, is referred to as a movable contactor supporting unit 10 for
convenience sake, A center axis 11 of the insulation spacer 2c is
disposed to be off-centered toward a side of the detachable unit
8 positioned in the lower part of the drawing as seen from a center
axis of the gas container 1.
[0032] In a space portion formed between the movable contactor
supporting conductor 9 and the insulation spacer 2c in the gas
container 1, that is, a space portion formed in a back side of the
movable contactor 5 as seen from the disconnector switch fixed contact
portion 4, there is disposed a fixed contact portion (hereinafter,
referred to as an earthing switch fixed contact portion 13) of the
earthing switch on the same axis as an axis between the disconnector
switch fixed contact portion 4 and the movable contactor 5.
£0033] An external lead-out terminal 14 doubles as a supporting
member of the earthing switch fixed contact portion 13 is mounted
to a mounting surface being a surface flat with the opening la of
the gas container 1. The earthing switch fixed contact portion 13
is to be grounded via the external lead-out terminal 14 doubling
the supporting member. It should be noted that in the present

embodiment a portion enclosed by a dashed line, the portion being
constituted with the earthing switch fixed contact portion 13 and
the external lead-out terminal 14, is referred to as an earthing
switch fixed side unit 15 for convenience sake.
[0034] For example, by converting a rotary movement of a driving
shaft 16 to a linear movement with a rack-and-pinion steering, a
linkage lever or the like, the movable contactor 5 is linearly driven
to be connected or separated to/from the disconnector switch fixed
contact portion 4 and the earthing switch fixed contact portion 13.
(0035] A reference numeral "21" shown in FIG. IB indicates an
operational device to rotate-drive the driving shaft 16 via an
insulation rod 22. h reference numeral "17" indicates an inspection
cover to airtightly seal the opening Id of a left side of the gas
container 1.
[0036] Next, the detachable unit 8 will be described with reference
to FIG. 4.The detachable unit 8 is a unit to connect or separate
an upper end portion 7T of the detachable conductor 7 to/from the
lower end portion 3T of the main bus-bar conductor 3. The detachable
unit 8 is constituted with components described below.
[0037] The detachable unit 8 is constituted with an insulation
spacer 2b, the detachable conductor 7 of each phase of three phases
each having been fixed in advance to a predetermined position of
the insulation spacer 2b, and a cylinder 19 which has a flange 19F
fixed by a bolt 18 to a metal mounting ring 2br provided in an outer
periphery portion of the insulation spacer 2b and which is airtightly
and slidably fitted to an inner periphery portion of the opening
lb of the lower part of the gas container 1 via a seal member, and
an attaching/detaching means 20 provided between the flange 19F of

the cylinder 19 and a container flange IF formed around the opening
lb of the lower part of the gas container.
[0038] The attaching/detaching means 20 is constituted with a stud
20s having one end portion of which is screwed to a lower surface
of the container flange IF, a nut 20nl fixing the stud 20s in a state
being upright in a forward and backward direction of the cylinder
19, and nuts 20n2, 20n3 disposed on both sides of a through hole
opened in the flange 19F of the cylinder 19 and screwed with the
stud 20s. As for the attaching/detaching means 20, when the nut
20n3 is screwed forward in a state that the nut 20n2 is loosened,
the detachable conductor 7 moves toward the lower end portion 3T
of the main bus-bar conductor 3 together with the cylinder 19 and
the insulation spacer 2b. Then, the detachable conductor 7 is
connected to the lower end portion 3T of the main bus-bar conductor
3 eventually. When the nut 20n2 is fastened in such a state and
pressed hard to the flange 19F, a connected state between the main
bus-bar conductor 3 and the detachable conductor 7 is maintained.
[0039] Next, assembly of the three-position disconnector
switch/earthing switch 100 and an operation of the three-position
disconnector switch/earthing switch will be described with reference
to FIG. 1A to FIG. 4.
(1) Assembling Process
[0040] (i) First, the insulation spacer 2a of the disconnector
switch fixed side unit 6 is mounted airtight to the opening la of
i the upper part of the gas container la, whereby the main bus-bar
conductor 3 in which the disconnector switch fixed contact portion
4 is bored is housed in the gas container 1.
[0041] (ii) Next, the earthing switch fixed side unit 15 is mounted

airtight to the mounting surface being the surface flat with the
opening la of upper part of the gas container 1, whereby the earthing
switch fixed contact portion 13 provided in a tip portion of the
earthing switch fixed side unit 15 is housed in the gas container
(ii) can precede the other.
[0042] (iii) Thereafter, the insulation spacer 2c of the movable
contactor supporting unit 10 is mounted to the opening lc of the
right side part of the gas container 1, whereby the movable contactor
5 supported by the movable contactor supporting conductor 9 is
disposed between the disconnector switch fixed contact portion 4
and the earthing switch fixed side unit 15 with predetermined
insulation distances apart each.
[0043] (iv) At a stage that the above-described process (iii) is
finished, the detachable unit 8 is not mounted to the opening lb
of the lower part of the gas container 1 yet. Thus, a state inside
the gas container 1 can be seen from the opening lb of the lower
part and a jig can also be inserted.
[0044] Thus, after the process (iii) is finished, a centering
adjustment operation is performed by the jig or viewing from the
opening lb of the lower part so that axes of the disconnector switch
fixed contact portion 4, the movable contactor 5 and the earthing
switch fixed contact portion 13 are disposed in alignment with one
another.
[0045] (v) After the operation of centering adjustment in the
above-described process (iv), the detachable unit 8 is mounted to
the lower part of the gas container 1 and an upper terminal of the
detachable conductor 7 is connected to a lower terminal of the main

bus-bar conductor 3. In the above operation, first, the cylinder
19 is fitted to the opening lb of the lower part of the gas container
1. Then, while the stud 20s fixed to be upright around the opening
lb of the lower part is in a state of being through the through hole
provided in the flange 19F of the cylinder 19, the nut 20n2 is loosen.
Subsequently, the nut 20n3 is turned in a screw forward direction,
whereby the cylinder 19 is pushed up from below and the detachable
conductor 7 fixed to the insulation spacer 2b is pushed forward in
an internal direction of the gas container 1.
[0046] Then, when the upper end portion 7T of the detachable
conductor 7 becomes in a state of being connected to the lower end
portion 3T of the main bus-bar conductor 3 with an adequate pressure,
the nut 20n2 is turned in a reverse direction to strongly press the
stud 20s to the flange 19F, so that a fixed state of the detachable
unit 8 to the gas container lower part is maintained. Hereby, the
assembly of the three-position disconnector switch/earthing switch
100 of the gas-insulated switchgear is completed.
(2) Operation of Three-position Disconnector Switch/Earthing Switch
[0047] FIG. 1A shows a state that the three-position disconnector
switch/earthing switch is in the OFF state. In other words, the
movable contactor 5 is housed in the movable contactor supporting
conductor 9 of the movable contactor supporting unit 10, and in a
state of not being connected to either the disconnector switch fixed
contact portion 4 or the earthing switch fixed contact portion 13,
that is, in a state of "disconnector switch OFF" and "earthing switch
OFF".
[0048] In the above state, when the operational device 21 is
operated for "disconnector switch ON" by a motor action by remote

control or a direct handle operation, a rotational force from the
operational device 21 is transmitted to a converting means converting
a rotary movement of a rack-and-pinion steering, a linkage lever
or the like to a linear movement, via the insulation rod 22 and the
driving shaft 16 in the gas container 1. Then, by this converting
means, the rotary movement is converted to the linear movement and
a driving force is transmitted to the three-phase movable contactor
5.
[ 0049] By the above driving force, the movable contactor 5 is moved
from the position in FIG. 1A to a main bus-bar conductor 3 side and
stops at a position in FIG. 2, in which the movable contactor 5 is
connected to the disconnector switch fixed contact portion 4. A
state in FIG. 2 is a state of "disconnector switch ON" and "earthing
switch OFF".
[ 0050 ] On the other hand, when the operational device 21 is operated
for "earthing switch ON", the movable contactor 5 is moved to the
opposite side of the main bus-bar conductor 2, that is, to an earthing
switch fixed contactor 13 side, and stops at a position in FIG. 3,
in which the movable contactor 5 is connected to the earthing switch
l fixed contact portion 13. A state in FIG. 3 is a state of "disconnector
switch OFF" and "earthing switch ON".
(Effect)
[0051] As described above, according to the present embodiment,
effects described below can be attained.
5 [0052] (i) The movable contactor 5 used by both the disconnector
switch and the earthing switch is disposed to be almost orthogonal
to the main bus-bar conductor 3 and the earthing switch fixed contact
portion 13 is disposed behind the movable contactor 5 in a manner

that the axes of the movable contactor 5 and the earthing switch
fixed contact portion 13 become aligned as seen from the disconnector
switch fixed contact portion 4, and there is disposed the detachable
unit 8 having the detachable conductor 7 to be connected or separated
to/from the lower end portion 3T of the main bus-bar conductor 3,
and further, the center axis 11 of the insulation spacer 2c of the
movable contactor supporting unit 10 supporting the movable contactor
5 is disposed to be off-centered toward the detachable unit 8 side
as seen from the center axis 12 of the gas container 1. As a result,
miniaturization and the assembly property of the three-position
disconnector switch/earthing switch can be improved.
[0053] (ii) Further, it is constructed so that the movable
contactor supporting unit 10 is inserted to the gas container 1 and
assembled after the disconnector switch fixed side unit 6 and the
earthing switch fixed side unit 15 are assembled in the gas container
1. As a result, it is possible to improve the centering adjustment
operation to dispose the axes of the disconnector switch fixed side
unit 6, the earthing switch fixed side unit 15 and the movable contactor
5 aligned with one another from the opening lb of the lower part
of the gas container 1.
[0054] (iii) Further, it is disposed so that the mounting surface
of the disconnector switch fixed side unit 6 of the gas container
1 and the mounting surface of the earthing switch fixed side unit
15 of the gas container 1 become the same mounting surface. As a
result, it is possible to improve the centering adjustment operation
to dispose the disconnector switch fixed side unit 6, the earthing
switch fixed side unit 15 and the movable contactor 5 aligned with
one another. It should be noted even if there is a level difference

between the mounting surface of the disconnector switch fixed side
unit 6 and the mounting surface of the earthing switch fixed side
unit 15, a similar effect can be attained as long as both the mounting
surfaces are almost parallel to each other.
[0055] (iv) Furthermore, since the detachable unit 8 is disposed
in the opposite side of the earthing switch fixed side unit 15, the
earthing switch fixed side unit 15 is not in a neighborhood. As
a result a local assembling space of the detachable unit 8 side can
be secured, improving the assembling property.
[0056] (v) Since the opening lb of the gas container 1, the opening
lb being the mounting surface of the detachable unit 8, is used at
a time of internal assembling, it is not required to provide the
gas container 1 with an unnecessary assembling hole. Therefore,
it becomes possible to construct the gas container 1 without reducing
strength of the container 1. Thereby, reliability of the device
is improved and the centering adjustment operation of the
three-position disconnector switch/earthing switch 100 by a jig or
viewing can be improved.
[0057] Further, a structure is adopted that the detachable
conductor 7 is slidably fit to the gas container 1 via the insulation
spacer 2b and the cylinder 19 to seal the gas. As a result, in
intercircuit unit connection at a local mounting location of the
gas-insulated switchgear, a connection operation to other equipment
can be easily done by extending/retracting the detachable conductor
7 in the longitudinal direction of the main bus-bar conductor 3.
[0058] (vi) Further, since it is constructed so that an operational
ground terminal is drew out per phase, an effect of improved
workability at a time of inspection of the gas-insulated switchgear

can be also attained in a three-position disconnector switch/earthing
switch 100 which is constituted small-sized.

WHAT IS CLAIMED IS:
1. A gas-insulated switchgear housing a main bus-bar
conductor and accommodating a three-position disconnector
switch/earthing switch, comprising;
a disconnector switch fixed contact portion;
an earthing switch fixed contact portion;
a movable contactor supporting conductor disposed between
both the contact portions; and
a movable contactor slidably supported by the movable
contactor supporting conductor to be connected or separated to/from
both the contact portions, in a gas container to which insulation
gas is filled,
wherein one end portion of the main bus-bar conductor is fixed
to a first insulation spacer while the other end portion is formed
to be connect able to a detachable conductor, and in a center portion
of the main bus-bar conductor, the disconnector switch fixed contact
portion in a direction orthogonal to a longitudinal direction of
the main bus-bar conductor is formed;
wnerein the movable contactor supporting conductor is fixed
by a second insulation spacer mounted to the gas container which
is on an axis orthogonal to an axis of the first insulation spacer;
wherein the earthing switch fixed contact portion is disposed
behind the movable contactor as seen from the disconnector switch
fixed contact portion; and
wherein the detachable conductor is fixed by a third insulation
spacer disposed in a position facing the first insulation spacer
and is connected or separated to/from the other end portion of the

main bus-bar conductor by moving forward or backward of the third
insulation spacer in an internal direction of the gas container.
2. A gas-insulated switchgear housing a main bus-bar
conductor and accommodating a three-position disconnector
switch/earthing switch, comprising;
a disconnector switch fixed contact portion;
an earthing switch fixed contact portion;
a movable contactor supporting conductor disposed between
both the contact portions; and
a movable contactor slidably supported by the movable
contactor supporting conductor to be connected or separated to/from
both the contact portions, in a gas container to which insulation
gas is filled,
wherein the gas container houses the main bus-bar conductor
and has two facing openings in a longitudinal direction of the main
bus-bar conductor and at least one opening in a direction almost
orthogonal to the longitudinal direction of the main bus-bar
conductor;
wherein a disconnector switch fixed side unit is mounted to
one of the two facing openings provided in the gas container, the
disconnector switch fixed side unit having a first insulation spacer
and the main bus-bar conductor whose one end is fixed to the first
insulation spacer, in a center portion of the main bus-bar conductor,
the disconnector switch fixed contact portion in a direction
orthogonal to the longitudinal direction of the main bus-bar conductor
being formed, and in the other end portion of the main bus-bar conductor
a connection portion to another conductor being formed;
wherein an earthing switch fixed side unit is mounted to a

mounting surface side of the disconnector switch fixed side unit
of the gas container, the earthing switch fixed side unit having
the earthing switch fixed contact portion and an external lead-out
terminal to connect the earthing switch fixed contact portion to
the outside;
wherein a movable contactor supporting unit is mounted to
the opening provided in a direction almost orthogonal to the
longitudinal direction of the main bus-bar conductor of the gas
container, the movable contactor supporting unit having a second
insulation spacer, the movable contactor supporting conductor fixed
to the second insulation spacer and disposed to face the disconnector
switch fixed contact portion, and the movable contactor slidably
supported by the movable contactor supporting conductor to be
connected or separated to/from either one of the disconnector switch
fixed contact portion and the earthing switch fixed contact portion;
and
wherein a detachable unit is mounted to the other opening
facing the disconnector switch fixed side unit of the gas container,
the detachable unit having a third insulation spacer mounted to be
able to move forward and backward in an internal direction of the
gas container, and a detachable conductor fixed to the third
insulation spacer and connectable or separatable to/from the
connection portion formed in the other end portion of the main bus-bar
conductor.
3. The gas-insulated switchgear as set forth in claim 2,
wherein a mounting surface of the disconnector switch fixed
side unit to the gas container and a mounting surface of the earthing
switch fixed side unit to the gas container are the same mounting

surface or parallel mounting surfaces.
4. The gas-insulated switchgear as set forth in claim 2,
wherein the detachable unit is disposed on the opposite side
of the earthing switch fixed side unit.
5. The gas-insulated switchgear as set forth in claim 2,
wherein a center axis of the second insulation spacer
constituting the movable contactor supporting unit is disposed to
be off-centered toward a side of a detachable unit as seen from a
center axis of the gas container.
6. The gas-insulated switchgear as set froth in claim 2,
wherein the external lead-out terminal is lead out per each
phase.
7. An assembly method of a gas-insulated switchgear having
a gas container which accommodates a three-position disconnector
switch/earthing switch constituted with a main bus-bar conductor,
a disconnector switch fixed contact portion, an earthing switch fixed
contact portion, a movable contactor supporting conductor disposed
between both the contact portions, and a movable contactor slidably
supported by the movable contactor supporting conductor to be
connected or separated to/from both the contact portions, the gas
container having two facing openings in a longitudinal direction
of the main bus-bar conductor and at least one opening in a direction
almost orthogonal to a longitudinal direction of the main bus-bar
conductor, and insulation gas being filled to the gas container,
the assembly method, comprising:
a disconnector switch fixed side unit mounting in which a
disconnector switch fixed side unit is mounted to one of two facing
openings provided in the gas container, the disconnector switch fixed

side unit having a first insulation spacer and amain bus-bar conductor
whose one end is fixed to the first insulation spacer, in a center
portion of the main bus-bar conductor, the disconnector switch fixed
contact portion in a direction orthogonal to the longitudinal
direction of the main bus-bar conductor being formed, and in the
other end portion of the main bus-bar conductor a connection portion
to another conductor being formed;
an earthing switch fixed side unit mounting in which an earthing
switch fixed side unit is mounted to a mounting surface side of the
disconnector switch fixed side unit of the gas container, the earthing
switch fixed side unit having the earthing switch fixed contact
portion and an external lead-out terminal to connect the earthing
switch fixed contact portion to the outside;
amovable contactor supporting unit mounting in which amovable
contactor supporting unit is mounted to the opening provided in the
direction almost orthogonal to the longitudinal direction of the
main bus-bar conductor of the gas container, the movable contactor
supporting unit having a second insulation spacer, the movable
contactor supporting conductor fixed to the second insulation spacer
and disposed to face the disconnector switch fixed contact portion,
and the movable contactor slidably supported by the movable contactor
supporting conductor to be connected or separated to/from either
one of the disconnector switch fixed contact portion and the earthing
switch fixed contact portion,* and
a detachable unitmounting in which adetachable unit is mounted
to the other opening facing the disconnector switch fixed side unit
of the gas container, the detachable unit having a third insulation
spacer mounted to be able to move forward and backward in an internal

direction of the gas container and a detachable conductor fixed to
the third insulation spacer and is connectable or separatable to/from
the connection portion formed in the other end portion of the main
bus-bar conductor.
8. The assembly method of the gas-insulated switchgear as
set forth in claim 7,
wherein, in the movable contactor supporting unit mounting,
a drive mechanism of the movable contactor is assembled by using
the opening of the gas container of amounting surface of the detachable
unit.
9. The assembly method of the gas-insulated switchgear as
set forth in claim 7,
wherein, in the movable contactor supporting unit mounting
after the disconnector switch fixed side unit mounting and the
earthing switch fixed side unit mounting, the movable contactor
supporting unit is mounted to the gas container and a centering
adjustment operation of axes of the disconnector switch fixed contact
portion, the earthing switch fixed contact portion and the movable
contactor is performed.

1. A gas-insulated switchgear housing a main bus-bar
conductor and accommodating a three-position disconnector
switch/earthing switch, comprising;
a disconnector switch fixed contact portion;
an earthing switch fixed contact portion;
a movable contactor supporting conductor disposed between
both the contact portions; and
a movable contactor slidably supported by the movable
contactor supporting conductor to be connected or separated to/from
both the contact portions, in a gas container to which insulation
gas is filled,
wherein one end portion of the main bus-bar conductor is fixed
to a first insulation spacer while the other end portion is formed
to be connect able to a detachable conductor, and in a center portion
of the main bus-bar conductor, the disconnector switch fixed contact
portion in a direction orthogonal to a longitudinal direction of
the main bus-bar conductor is formed;
wnerein the movable contactor supporting conductor is fixed
by a second insulation spacer mounted to the gas container which
is on an axis orthogonal to an axis of the first insulation spacer;
wherein the earthing switch fixed contact portion is disposed
behind the movable contactor as seen from the disconnector switch
fixed contact portion; and
wherein the detachable conductor is fixed by a third insulation
spacer disposed in a position facing the first insulation spacer
and is connected or separated to/from the other end portion of the
main bus-bar conductor by moving forward or backward of the third
insulation spacer in an internal direction of the gas container.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=dT3TbNkQJRc9VRKAwbOL8g==&loc=wDBSZCsAt7zoiVrqcFJsRw==

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Patent Number

278708

Indian Patent Application Number

90/KOL/2009

PG Journal Number

54/2016

Publication Date

30-Dec-2016

Grant Date

28-Dec-2016

Date of Filing

16-Jan-2009

Name of Patentee

KABUSHIKI KAISHA TOSHIBA

Applicant Address

1-1, SHIBAURE 1-CHOME, MINATO-KU, TOKYO

Inventors:

#	Inventor's Name	Inventor's Address
1	AKIHISA MUKAIDA	C/O. KABUSHIKI KAISHA TOSHIBA 1-1, SHIBAURE 1-CHOME, MINATO-KU, TOKYO

PCT International Classification Number

H02B13/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2008-034781	2008-02-15	Japan