Claims:We claim:
1. A system for orientation and extension features of gas insulated bus and switchgear bays, the system comprising:
a main bus (06) split into a two main bus (6A, 6B) by a sectionalizer bay (18), a separate potential transformer (PT) bays (19) is mounted on the both sections of the two main bus (6A, 6B) in the radial direction, the PT bay (19) is connected to a three-way connector (12) with suitable bend/right angled connections to change the direction of the main bus (06) on either side of the two main bus bars (6a and 6b);
a bus sectionalizer bay (18) and two radial buses (11A,11B) are connected one on either side of bus section (06A, 06B) through the three-way connector (12), a radial compact bus (11) has three ports to connect to a three phases of potential transformer (PTs) (21) through a disconnector switches (16), the disconnector switches (16) and an earthing switch (13) are connected between the two main bus bars (6A, 6B) with an appropriate expansion joint (20);
the HT connections (22) are plug-in-type providing 90 degree of angle on either side of the radial compact bus (11) or the main bus (06); and
a hair pin gas insulated bus (23A, 23b) integrated with the bus sectionalizer bay (18), the hair pin bus (23A.23B) provided on each part of bus, wherein at least one part of the bus having bays like incomer, transformer and feeders along with the PT bays (19), a stem (23C) of each bus of hair pin bus (23A, 23B) arrangement is provided in the radial direction, the hair pin bus (23A, 23B) is coupled to the other bus through a bus coupler (27).

2. The system (100) as claimed in claim 1, wherein the three-way connector (12) is used for different configurations of an existing double bus and a new gas insulated double bus switchgear with extension.

3. The system (100) as claimed in claim 1, wherein the new bus (11) in radial direction to existing bus (06) to optimize the GIS bay dimensions.

4. The system (100) as claimed in claim 1, wherein an interconnection between existing bus and new bus proposed in radial direction (11) to optimize GIS bay dimensions.

5. The system (100) as claimed in claim 1, wherein the incomers is provided on any side of the hair pin arrangement (23A, 23B) depending on direction of an incoming XLPE cable.

6. The system (100) as claimed in claim 1, wherein the gas insulated bays are provided in square / rectangle shape building.

7. The system (100) as claimed in claim 1, wherein the back-to-back gas insulated bays are available in limited length of building or precisely square shape buildings.

8. The system as claimed in claim 1, wherein a double disconnector switch (24) with a common earthing switch (13) is used to provide the double bus arrangement.

9. The system (100) as claimed in claim 1, wherein each bus of compact or segregated type run like the hair pin bus (23A, 23B) and is parallel to the other bus.

10. The system (100) as claimed in claim 9, wherein the gap of hair pin bus (23) arrangement circuit breaker (14) of each bay is connected in back-to-back configuration.

11. The system (100) as claimed in claim 10, wherein each bus is connected to the circuit breaker (14) through the double disconnector switch (24).

12. The system (100) as claimed in claim 1, wherein the double bus is connected to the circuit breaker through the double disconnector switch (24), the double disconnector switch (24) further consists of:
a two disconnector switches in tandem, either one the disconnector switches can be in ON position or both the disconnector switches can be ON position or both the disconnector switches can be in OFF condition; and
a common conductor (25) connected to moving contact (MC) housing (26) and the conductor is grounded through earthing switch (13).

13. The system (100) as claimed in claim 1, wherein a local control panel (28) is arranged in front of each bay and provided all around the room.
, Description:A SYSTEM FOR ORIENTATION AND EXTENSION FEATURES OF GAS INSULATED BUS AND SWITCHGEAR BAYS
TECHNICAL FIELD
[0001] The present invention relates to extension and integration of gas insulated substation bays to the existing three phase Gas insulated Switchgear (GIS) of a particular design with single/double Gas insulated bus configuration. The invention specifically proposed a novel integration of GIS bays by extending the bus in different orientations with the existing single / double bus and concept of necessary modules and design thereof. The invention further related to novel extension of GIS bays in buildings where space is a major constrain.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention.
[0003] Gas insulated substations are mostly indoor type i.e. they are installed in the buildings. Most of the Gas Insulated substations are located in the urban area, where space shall be the main constrain for installation of the bay. In general, in a Gas-Insulated Substation, the three-phase main bus consisting of single-phase high voltage/tension (HT) terminals arranged in parallel with one another laid either parallel to the length of room or width of the room. All the bays connected to the bus are arranged perpendicular to these buses and all these bays will be oriented parallel to each other with some space clearance for maintenance purpose.
[0004] The three phase gas insulated main bus module consists of single enclosure with three HT terminals placed at pre-defined phase distances. Compact Bus module consists a metallic chamber filled with SF6 gas and the HT terminals are supported with rib insulators. In practical electric power systems, it is often required to extend the bays available in the substations based on the future power requirements at the utility areas. Integration of the new gas insulated electric system with existing gas insulated bus in available space is a complex issue in certain situations. In such circumstances there is a need of suitable system to interconnect those two electric systems for best utilization of the space available in the GIS building.
[0005] Prior art:
[0006] The present invention relates to three phase gas insulated switchgear, particularly integration of three phase bus bar module to the gas insulated switchgear bays as an extension. It also relates to the utilization of the space available in the GIS building with various orientations of the main bus. In conventional systems, gas insulated switchgear bays are installed on the gas insulated main bus which always run in longitudinal direction and the various bays in the substations are connected perpendicular to this main bus. In practical electric power systems, it is often required to extend and integrate the new gas insulated switchgear system with existing gas insulated bus. In such circumstances there is a need of suitable system which shall interconnect these two electric systems and have extension of bay at the ease. In some of the conventional arrangements, like US 3302069A, segregated phase assembly all the different phases are placed at different heights/levels in the GIS building to make it compact. They termed it as phase layers, situated one above the other and separated from each other horizontally. HT terminal connections of each phase assembly are extended parallel to one another in the same horizontal plane in the upper part of the phase layer.
[0007] In other patents, US 6515247, US 7675738B2, US 5177664, various conventional substation arrangements discussed which show the longitudinal orientation of the main bus. As discussed above, various non-standard mounting arrangements for GIS modules have been used to integrate gas insulated switchgear modules to the gas insulated bus due to space constrains. Based on this requirements different interconnecting modules are being used. These modules vary from one substation to another substation requirement. Such designs are critical at higher system voltages. Hence, the present patent aims to address the above problems.

OBJECTS OF THE DISCLOSURE
[0008] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.
[0009] The principal object of the present subject matter is to propose an interconnection between existing bus and new bus proposed in radial direction to optimize GIS bay dimensions.
[0010] Another object of the invention is to propose a compact interconnecting system between existing gas insulated bus with new gas insulated switchgear bay.
[0011] Another object of the invention is to propose an interconnection between existing bus and new bus for utilizing the GIS room’s depth/width for extension bays.
[0012] Another object of the invention is to propose high voltage connection from existing bus to new extension bus proposed.
[0013] Another object of the invention is to propose an interface between existing GIS bus and new bus for extension bay in smallest available space and interface system shall be as compact as possible.
[0014] A still further object of the invention is to propose the interface system shall be suitable for different configurations of existing double bus and new gas insulated double bus switchgear with extension.
[0015] A still another object of the invention is to propose a three phase bus bar module with a provision of plug-in to other GIS three phase or single phase modules.
[0016] A still another object of the invention is to propose more number of gas insulated bays in square building otherwise it is not possible to install with existing practices.
[0017] A still another object of the invention is to propose back-to-back gas insulated bays in limited length / square buildings otherwise it is not possible to install with existing practices.
[0018] A still another object of the invention is to propose gas insulated bus in hair pin manner so that more number of bays can be installed in the available foot print.
[0019] These and other objects and advantages will become more apparent when reference is made to the following description and accompanying drawings.
SUMMARY
[0020] The proposed gas insulated bus is directly integrated with existing bus through interface module in radial direction to accommodate more number of bays in existing space of building. More number of gas insulated bays in GIS building can be possible with proposed scheme otherwise it is not possible to install with existing practices. A novel hair pin type bus is proposed to keep almost double number of bays in existing room length. Each side of hair pin i.e., each part of bus shall have bays like incomer, transformer and feeders, PT bays and joined by bus sectionalizer bay. Similar hair pin type double bus is proposed with bus coupler between buses and bus sectionalizer in each bus.
[0021] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The illustrated embodiments of the subject matter will be understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
[0023] Fig. 1 shows a conventional arrangements of the gas insulated switchgear, in accordance with an embodiment of the present subject matter;
[0024] Fig. 2 shows a conventional gas insulated switchgear bays, in accordance with an embodiment of the present subject matter;
[0025] Fig. 3 shows a compact gas insulated bus, in accordance with an embodiment of the present subject matter;
[0026] Fig. 4 shows an integration of axial and radial bus, in accordance with an embodiment of the present subject matter;
[0027] Fig. 5 shows a proposed extension of bus sectionalizer and PT bays for single bus GIS, in accordance with an embodiment of the present subject matter;
[0028] Fig. 6 shows a hair pin arrangement of single bus GIS with multiple GIS bays, in accordance with an embodiment of the present subject matter;
[0029] Fig. 7 shows a double disconnector switch assembly, in accordance with an embodiment of the present subject matter;
[0030] Fig. 8 shows a hair pin arrangement of double bus GIS with bus coupler bay, in accordance with an embodiment of the present subject matter; and
[0031] Fig. 9 shows a hair pin arrangement of double bus GIS with bus coupler and bus sectionalizer, in accordance with an embodiment of the present subject matter.
[0032] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0033] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
[0034] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0035] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a",” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0036] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0037] In addition, the descriptions of "first", "second", “third”, and the like in the present invention are used for the purpose of description only, and are not to be construed as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include at least one of the features, either explicitly or implicitly.
[0038] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. ‘
[0039] A compact three phase bus consists of three high tension (HT) bus bars (01) arranged either in a horizontal row or at vertices of equilateral triangle or in right angled or in circular or in any arbitrary angled configuration. Sometimes these bus bars (01) are of independent phase type and they are of double bus configuration. Phase-to-phase distance of these bus bars (01) are different and they are oriented at different angles.
[0040] Figure 1 shows conventional gas insulated switchgear arrangements.
[0041] Figure 2 shows conventional double bus gas insulated switchgear bays. The compact gas insulated bus bar comprises of three bus bars (01) in single grounded metallic enclosure (02). Three Bus bars (01) are made of high electrical conductivity material to enable efficient current flow with minimal power loss and is insulated from the grounded metallic enclosure (02) with designed SF6 gas density. The support insulator (03) is made of SF6 gas compatible filled epoxy material. The support insulator / rib insulator (03) holds each of the bus bars (01) through sockets/HT Integrator (04) in such a configuration where each bus bar (01) is placed at the vertices of an equilateral triangle or right angled or in any arbitrary angled configuration in a grounded metallic enclosure (02) filled with SF6 gas at designed density. The socket / HT integrator (04) is made of high electrical conductivity material makes the electrical connection between rib insulator (03) and bus bars (01). Each of the bus bar (01) is ended with termination shield (05), which controls the electric stress between the bus bars (01) and bus bars to the grounded enclosure (02). The arrangement of three bus bars (01) along with support insulators (03), HT integrators (04), HT shields (05) and grounded enclosure (02) is known as compact three phase bus (06). The angled terminal (07) and straight conductor/terminal (08) transfers current from bus bar (01) to high voltage terminal of other insulation media or gas insulated module through current transfer bridge (09) and support insulator (10). The straight terminal (08) extends the electrical connection orthogonally from bus bar (01) to other insulation media whereas the angled terminals (07) extend the electrical connection radially at a designed angle from bus bars (01) to other insulation media. The angled terminal (07) / straight terminal (08) provide the flexibility in design; these terminals shall rotate radially at any desired angle based on the requirement.
[0042] Figure 3 shows the compact gas insulated bus bar assembly (06). The present patent covers integration of existing gas insulated substation bays with compact gas insulated bus (06) and additional gas insulated switchgear bays where gas insulated bus is extended in axial (06) / radial directions (11). This integration helps in achieving space reduction by the installation of buses in axial direction so that full space available in the GIS room can be utilised. This radial integration of the bus leads to change of philosophy of rectangle installation of GIS bays to square installation in GIS bays. Generally, a gas insulated switchgear bay consists of compact bus (06), maintenance earthing switches (13), Circuit breaker (14), current transformer (15), line / feeder side disconnector switch (16) and fast acting earthing switches (17). In a single bus arrangement only one compact bus is required and in double bus arrangement two compact buses to be provided with two-line side disconnector switches (16). It is essential in today scenario that extension of existing GIS bays of limited dimensions of building. Most of the GIS installations in the world are kept in rectangular rooms and cannot extend beyond one or two bays in the existing space unless it is pre-planned for such extensions. The radial integration is of two parts and first one is an interface module (12) between existing gas insulated bus (06) and proposed radial gas insulated bus (11) and second one is an integration of new radial bus (11) with proposed bus sectionalizer Bay (18) and PT bays (19). The interface module (12) consisting of either T-enclosure or three-way enclosures or bend enclosures, made in such a way that, that bus configuration will not change or disturbed. In compact 3-phase bus, the rib insulators (03) are fixed at the angled position to provide support to the three phase conductors. HT bus bars / conductors (01) are connected to Rib Insulators (03) through plug-in connection.
[0043] Figure 4 shows the compact integration of existing bus (02) and proposed radially placed gas insulated bus (11). For redundancy of supply and easy maintenance of the substation for single bus bar systems, bus sectionalizer bay (18) with separate PT bays (19) for the both sections of the bus are required. To meet this requirement, it may not be possible to provide bus sectionalizer bay (18) in the existing space of PT bay (19A). In the proposed patent, to provide the bus sectionalizer bay (18), the space available with the Bus PT bay (19A) is utilised with novel concept of radial bus (11) and the PT bays (19) for the both sections have been proposed to install towards the end of bus section (part of Bus) in radial direction. The present patent also aims to propose a scheme of large number of bays, where limited length of building is available or precisely square type building instead of rectangular type of building for GIS installation. The proposed scheme can address even for double bus bar GIS installations of larger number of bays in smaller available building areas.
[0044] The most common elements required for extension of compact bus (06) is three-way connector / T-connector (12) with suitable bend /right angled connections to change the direction of bus bar on either side of it. Required disconnector switch (16) and earthing switch (13) are connected between these bus bars with appropriate expansion joint (20). Necessary PT bays (19) are added to each section of bus in radial direction because of non-availability of space. These PT bays (19) will be added with a three-way connector / T-connector (12) with suitable bend /right angled connections to change the direction of bus. The radial compact bus (11) has three ports to connect to three phases of PTs (21) through disconnector switches (16). The bay width of PT bay (19) reduces to as low as 20% of existing PT bay (19A). The same arrangement can be made to each section of bus (06A, 06B) to measure voltage of each section of bus. The three-way connector (12) does not require separate rib insulator / support insulator (03) to integrate bus bars (06,11). Novelty of proposed design is that same compact bus (06) is used to integrate bus (11) but in radial direction using three-way connector (12). For bus sectionalizer bay (18), two radial buses (11A,11B) are connected one on either side of bus section (06A,06B) through three-way connector (12). These radial buses (11A,11B) are integrated through disconnector switch (16) with earthing switch (13) on either side. To overcome mechanical discrepancies and leakages, the two buses are connected to respective earthing switches (13) through expansion joint or bellow (20). Even though bus runs in radial direction, sequence of three phases shall be maintained. For integrating buses in radial direction, 90 degree angled HT connection (22) is preferred. These HT connections (22) are plug-in-type on either side of bus (06,11).
[0045] Figure 5 shows proposed Extension of Bus sectionalizer and PT bays for a single bus GIS. This type of radial extension of GIS bays may give flexibility in optimising GIS bay configuration in existing space. The proposed concept addresses the issues in special situation, where building length and breadth are more or less equal and length is limited unlike standard rectangular buildings. In other words, existing length of building is not sufficient for required number of bays as per conventional schemes. In order to meet this requirement, compact gas insulated bus has been formed like a novel hair pin type bus (23) to keep almost double number of bays in existing room length. Each side of hair pin type gas insulated bus (23A.23B) i.e., each part of bus shall have bays like incomer, transformer and feeders along with PT bays. The two parts of hair pin type bus shall be integrated with bus sectionalizer bay (18). Novelty of present scheme is that the incomers can be given on any side of hair pin depending on direction of incoming XLPE cable. In the available space of three bays length of GIS building, approximately eight numbers of GIS bays could be installed with easy maintenance and reduced cost of GIS bays.
[0046] Figure 6 shows a single bus formed like a hair pin with bus sectionalizer bay. In case of single bus, bus sectionalizer (18) and PT bays (19) have been provided in radial direction for each part of bus section. This radial PT bay can be made at entrance or at middle depending up on space availability. One more advantage with this scheme is bus sectionalizer can be made with radial bus extensions. With this arrangement extension of many bays can be possible in available space. This type of arrangement can be made for double bus arrangement also. For better optimisation of space and cost of project, each row of the bus can be staggered in space.
[0047] For double bus arrangement, it is necessary to propose new disconnector switch known as double disconnector switch (24) with common earthing switch (13). In proposed arrangement, circuit breakers (14) will be arranged as back to back. Each bus is of compact or segregated type run like hair pin fashion and is parallel to other bus. In the gap of hair pin bus (23) arrangement, circuit breaker of each bay is connected as back-to-back configuration. Each bus is connected to circuit breaker through double disconnector switch (24). Double disconnector switch (24) consists of two disconnector switches in tandem, either one can be in ON position or both can be ON position or, both can be in OFF condition. There is a common conductor (25) which is connected to Moving Contact (MC) housing (26). This particular conductor is grounded through earthing switch (13).
[0048] Figure 7 shows the double disconnector switch assembly. The ends of each bus which run like hair pin and shall be facilitated with PT bays (19) in radial direction. The stem (23C) for each side of hair pin bus shall be in radial direction and has provision to couple to other bus through bus coupler (27) arrangement. Alternatively, each bus shall have provision of bus sectionalizer like single bus arrangement. The local control panel (28) will be arranged in front of each bay and provided all around the room. Double bus arrangement is proposed with bus coupler (27) between buses and sectionalizer in each bus. Bellow or expansion joint (20) is provided between each bay for maintenance of bay.
[0049] Figure 8 shows the double bus hair pin arrangement with bus coupler arrangement.
[0050] Figure 9 shows the double bus bar pin arrangement with bus coupler and bus sectionalizer in each bus.
[0051] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.