Claims:We claim:
1. A system (100) for a dual mode compact gas insulated bus (103) comprising:
at least one air insulated switch gear and at least one gas insulated switch gear having a plurality of bays (101, 102) with one or more bus arrangement (101a, 102a), the air insulated switch gear and gas insulated switch gear are integrated with a dual mode compact gas insulated bus (103), the dual mode compact gas insulated bus (103) is extended in the form of gas insulated enclosure having a gas insulated bus (102a), and used to extend the gas insulated switchgear bays (102);
a grounded metallic enclosure (104) used to enclose the bus bar (111) further comprises:
a plurality of air insulated switch gear side ports (105) and a plurality of gas insulated switch gear side ports (106);
a flexible high tension (HT) shields (107) and a plug-in adapter (108) placed in any angled configuration in which each phase conductor is positioned at each vertex of an equilateral triangle to form a hybrid module, and provides integration of an air insulated switchgear bays (101) to the gas insulated switchgear bays (102);
an angled-cum-straight terminal (109) and a straight-cum-straight terminal (110) configured to transfers current from the bus bars (111) to high voltage terminal of gas insulated module through a flexible contact (112) covered by a HT integrated shield (113); and
an angled enclosure (114) is arranged in series to the air insulated switch gear side ports (105) to commensurate HV connection to a gas-to-air bushing (115).

2. The system (100) for the dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the dual mode compact bus bar (103) configured to act as the gas insulated bus (102a) for the gas insulated switch gear and an extended air insulated bus (101a) for the air insulated switch gear.

3. The system (100) for the dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the air insulated switch gear (AIS) side ports (105) and the gas insulated switch gear side ports (106) provided on grounded enclosure (104) of dual mode compact gas insulated bus (116a, 116b) to commensurate high voltage connection to air insulated switchgear bus.

4. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the bus bars (111) terminated with the flexible HT shields (107) and the plug-in adapters (108).

5. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the dual mode gas insulated bus (116a) configured to act as an interference module between the gas insulated switch gear bay (101) and the air insulated switch gear bus (102).

6. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the dual mode compact gas insulated bus (103) further comprises the high voltage connection which is extended to the gas insulated switchgear equipment (102) through a support insulator (117).

7. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the dual mode compact gas insulated bus (103) further comprising a dual mode compact bus bar module which is used as extension of the air insulated bus (101a) of the air insulated switchgear and extended simultaneously as the gas insulated bus (102a) without any switchgear in which the gas insulated switchgear is of indoor type.

8. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the dual mode compact gas insulated bus (103) further comprising a dual mode compact bus bar module which is used as extension of the air insulated bus (101a) of the air insulated switchgear and extended simultaneously as the gas insulated bus (102a) as well as gas insulated switchgear bays (102) in case GIS is indoor type and the extension is also possible with double bus.

9. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the dual mode compact gas insulated bus (103) further comprising a dual mode compact bus bar module which is used as extension of the air insulated bus (101a) of the air insulated switchgear and extended simultaneously as the gas insulated bus (102a) as well as gas insulated switchgear bays (102) in case GIS mix of indoor and outdoor type and the extension is also possible with double bus.

10. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the angled-cum-straight terminal (109) is extended from bus bar to the air insulated switchgear side bus (101a) and the gas insulated switchgear bays (102).

11. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the straight-cum-straight terminal (110) is extended from bus bar to the air insulated switchgear side bus (101a) and the gas insulated switchgear bays (102).

12. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the angled enclosures (114) is configured to rotate clock wise or antilock wise depends upon the required phase distance with air insulation.

13. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein each phase of the gas insulated bus (102a) is supported by an independent rib insulator (119) which is supported from the grounded metallic enclosure (104) non-concentrically.

14. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the three independent phase rib insulators (119) located at a pre-defined angle.

15. The system (100) for dual mode compact gas insulated bus (103) as claimed in claim 1, wherein the angled enclosures (114) having the same design for all three phases.
, Description:A DUAL MODE COMPACT GAS INSULATED BUS
TECHNICAL FIELD
[0001] The present subject matter described herein, relates to a dual mode compact gas insulated bus. More particularly, the present invention relates to an improved three phase compact bar module. The three phases in single enclosure is used to inter connect with the modules of a three phase electrical power systems. A dual mode compact bus is used to integrate to the air insulated switchgear bays to the gas insulated switchgear bays.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention.
[0003] The Expansion of existing conventional air insulated substations are generally carried out using hybrid gas insulated switchgear (H-GIS). However, such type of expansion is also limited as the space required by H-GIS is about 60 % of air insulated switchgear. At the same time, number of H-GIS can be accommodated in the available space of air insulated substation is limited. In order to maintain minimum air clearances as per standards between H-GIS bays, it is not possible to reduce footprint beyond certain level even though all modules of H-GIS are gas insulated type. In view of above, it is required to integrate Air insulated switchgear which is located in yard to the gas insulated switchgear located either in building or in yard.
[0004] Conventionally, an incomer bay or two incomer bays is /are required in GIS to integrate air insulated bus to gas insulated switchgear (refer US 2004OO37025A1, CN103078261A).
[0005] In view of above, a dual mode gas insulated bus is proposed which acts as an air insulated bus as well as gas insulated bus simultaneously. Further, in conventional bus bar arrangements, the bus bars are placed in a row or in right angle configuration and is an independent module for each hybrid GIS bay.
[0006] With reference to Pat. No. RU 2523429, the bus bars are arranged in a row and enclosure dimensions’ increase significantly with system voltage. In conventional arrangements, the bus of one phase of a three-pole bus bar is made with bends and curves around the bends of adjacent phases. Hence electrostatic field levels are quite high. Following are some of the drawbacks with the conventional bus bar arrangements:
[0007] If the bus bar arrangement is in a row, the dimensions of enclosure are quite high. The compactness of equipment is limited.
[0008] If the bus bar arrangement is in a row, there is a resultant magnetic field on the grounded enclosure and may result to eddy currents for some type of enclosure materials.
[0009] In the conventional right angled arrangement, current transfer takes place through complex machined terminals, bends etc.
[0010] In the conventional right angled arrangement, uniform electrostatic field levels between the phases are quite difficult to achieve because of HT crossings across bus bar phases.
[0011] With reference to Pat. No. US 7485807 and US20030079906A1, the three bus bars are arranged in a particular orientation and supported by post insulator. The grounded enclosure dimensions’ increase significantly with system voltage depending on post insulator design requirements. In conventional arrangements, post insulator height along with minimum distance between buses decide the grounded enclosure dimensions. In some of the conventional bus bar arrangements Pat. No. US 7612293B2, DE 3137783 and US 4404423 each bus bar is supported by a post insulator. The post insulators are either single post or tri post type. If it is single post, then there is requirement of minimum two to three post insulators for the support of bus bar at each location. If three phase insulator is used to support three phase bus bars, flexibility in the extension of bus is limited. The rejection rate of three phase insulator or tri post insulator is more than an independent insulator both at production and operation and hence uneconomical. The assembly of multiple post insulators on each phase of the three phase bus bar arrangement becomes complex and may result to bulky in size or complex in nature. If we use multiple post insulators mounted on plates and located through grounded housing may increase number of leakage points and hence not reliable.
[0012] Therefore, there is a need for a dual mode compact gas insulated bus which is configured to provide a three phase bus bar module which can be used as a bus for gas insulated switchgear bays as well as for air insulated switchgear bays.

OBJECTS OF THE DISCLOSURE
[0013] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.
[0014] The principal object of the present subject matter is to provide a three phase bus bar module which can be used as a bus for gas insulated switchgear bays as well as for air insulated switchgear bays. The same shall be extendable for double bus configuration.
[0015] Another object of the present subject matter is to provide a three phase bus bar module which can be simultaneously used as incomer for air insulated bus and can be extended as gas insulated bus without any switchgear which otherwise required.
[0016] Another object of the present subject matter is to provide a compact three phase bus bar module which is simultaneously used as incomer for air insulated bus and can be extended as gas insulated bus. This bus shall be used for extending gas insulated switchgear bays like transformer feeders, sectionalizer etc.
[0017] Another object of the present subject matter is to provide a three phase gas insulated bus bar with smallest possible distance between bus and the grounded enclosure.
[0018] Another object of the present invention is to provide a reliable insulator which can support each phase of HT conductor non–concentrically and provide composite insulation between each phase of bus and nearest ground plane of the enclosure.
[0019] Another object of the present invention is to provide a three phase bus bar module with equilateral triangle configuration or right angled configuration or any arbitrary angled configuration in which each phase conductor will be positioned at each vertex of an equilateral triangle or right angle or any pre-defined angle with angular disposition of the phases so that terminal connections in other insulation media shall be maintained with phase-phase and phase-ground electric isolation.
[0020] Another object of the present invention is to provide a three phase bus bar module to provide single electrical connection from AIS side switchgear to GIS side switchgear modules using angled-cum-straight terminals. This integration shall facilitate transfer of current through gas insulated bus and supported by suitable insulator.
[0021] Another object of the present invention is to integrate AIS to gas insulated switchgear so that multiple bays can be installed in existing switchyard which otherwise not possible with hybrid GIS.
[0022] Another object of the present invention is to integrate AIS to gas insulated switchgear of mixed type i.e., both indoor and outdoor type, so that multiple bays can be installed in existing switchyard which otherwise not possible with hybrid GIS.
[0023] Another object of the present invention is to design unique angled enclosures for all three phases and achieve required phase distance with air insulation.
[0024] These and other objects and advantages will become more apparent when reference is made to the following description and accompanying drawings.
SUMMARY
[0025] This summary is provided to introduce concepts related to a system for dual mode compact gas insulated bus
[0026] The present system for dual mode compact gas insulated bus is divided into three parts. One part is air insulated switchgear of multiple bays with single or double bus arrangement. Second is gas insulated switchgear of multiple bays with single or double bus arrangement. To integrate these two switchgear, a module has been proposed as third part. This module is named as dual mode compact gas insulated bus. Accordingly, a dual mode compact gas insulated bus is provided in such a way that same bus bar module can be simultaneously used as a bus for gas insulated switchgear bay as well as for Air insulated switchgear bay. Accordingly, the gas insulated three phase bus bar module that can be used to integrate Air insulated substation and gas insulated substation without any hybrid switchgear modules is provided. Accordingly, there is provided a three phase bus bar module in which “conductors (bus bars)” placed in a metal enclosure in equilateral triangle configuration or right angled configuration or any arbitrary angled configuration to extend the current transfer from air insulated bus bar to gas insulated switchgear modules through “flexible contact” with “HT integrated shield” via multiple sets of “metallic ports”; unique angled-cum-straight terminals” and “straight-cum-straight terminals”.
[0027] A system for dual mode compact gas insulated bus comprising one air insulated switch gear and at least one gas insulated switch gear having multiple bays with single or double bus arrangement. The air insulated switch gear and gas insulated switch gear are integrated with a dual mode compact gas insulated bus (103). The dual mode compact gas insulated bus is extended in the form of gas insulated enclosure inside building having a gas insulated bus.
[0028] The gas insulated bus is used to extend a plurality of gas insulated switchgear bays. A grounded metallic enclosure used to enclose the bus bar. The bus bar further comprises an air insulated switch gear side ports and a plurality of gas insulated switch gear side ports.
[0029] The flexible HT shields and a plug-in adapters placed in any angled configuration in which each phase conductor is positioned at each vertex of an equilateral triangle or right angle or any pre-defined angle which forms a hybrid module to provide integration of an air insulated switchgear bays to the gas insulated switchgear bays.
[0030] An angled-cum-straight terminal and a straight-cum-straight terminal configured to transfer current from the bus bar to high voltage terminal of gas insulated module through a flexible contact covered by a HT integrated shield.
[0031] An angled enclosure is arranged in series to air insulated switch gear side ports to commensurate HV connection to gas-to-air bushing.
[0032] The dual mode compact bus bar configured to act as the gas insulated bus for the gas insulated switch gear and an extended air insulated bus for the air insulated switch gear.
[0033] The air insulated switch gear (AIS) side ports and the gas insulated switch gear side ports provided on grounded enclosure of dual mode compact gas insulated bus to commensurate high voltage connection to air insulated switchgear bus.
[0034] The air insulated switch gear side ports and the gas insulated switch gear side ports to commensurate high voltage connection to gas insulated switchgear.
[0035] The dual mode compact bus bar module which is used as extension of air insulated bus of the air insulated switch gear.
[0036] The air insulated bus is extended simultaneously as gas insulated bus without using any switchgear in case the gas insulated switch gear (GIS) is of indoor type.
[0037] The bus bars terminated with the flexible HT shields and the plug-in adapters in any configuration for example equilateral triangle configuration, right angled configuration and any arbitrary angled configuration.
[0038] The dual mode gas insulated bus act as an interference module between the gas insulated switch gear bay and the air insulated switch gear bus.
[0039] The dual mode compact gas insulated bus further comprises the high voltage connection which is extended to the gas insulated switchgear equipment through a support insulator.
[0040] The dual mode compact bus bar module which is used as extension of air insulated bus of the air insulated switchgear and extended simultaneously as gas insulated bus without any switchgear in case gas insulated switchgear is of indoor type and it also possible with double bus.
[0041] The dual mode compact bus bar module is used as an extension of air insulated bus of the AIS and extended simultaneously as gas insulated bus as well as gas insulated switchgear bay in case GIS is outdoor type and it also possible with double bus.
[0042] The dual mode compact bus bar module which is used as extension of air insulated bus of the AIS and extended as gas insulated bus as well as gas insulated switchgear bay in case GIS is mix of indoor and outdoor type and it also possible with double bus.
[0043] The angled-cum-straight terminal and the straight-cum-straight terminal is used to provide the flexibility in design.
[0044] The angled-cum-straight terminal and the straight-cum-straight terminal is used to rotate radially at any desired angle based on the requirement.
[0045] The angled-cum-straight terminal is extended from bus bar to the air insulated switchgear side bus and the gas insulated switchgear bays.
[0046] The straight-cum-straight terminal is extended from bus bar to the air insulated switchgear side bus and the gas insulated switchgear bays.
[0047] The angled enclosures having the same design for all three phases.
[0048] The angled enclosures are configured to rotate depending on the required phase distance with air insulation.
[0049] Each phase of the gas insulated bus is supported by independent rib insulator which is supported from grounded metallic enclosure non-concentrically.
[0050] The three independent phase rib insulators located at a pre-defined angle.
[0051] 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
[0052] 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:
[0053] Fig. 1 illustrates a dual mode compact gas insulated bus, in accordance with an embodiment of the present subject matter;
[0054] Fig. 2 illustrate an angled-cum-straight terminal and straight-cum-straight terminal of proposed dual mode bus bar system, in accordance with an embodiment of the present subject matter;
[0055] Fig. 3 illustrate a support insulator with flexible contact and HT integrated shield, in accordance with an embodiment of the present subject matter;
[0056] Fig. 4 illustrate a dual mode compact bus arrangement with rib insulators and terminal arrangement, in accordance with an embodiment of the present subject matter;
[0057] Fig. 5 illustrate a dual mode compact bus and integration to AIS and GIS switchgear, in accordance with an embodiment of the present subject matter;
[0058] Fig. 6 illustrates a dual mode compact bus for multiple bays with suitable bellow or expansion element, in accordance with an embodiment of the present subject matter;
[0059] Fig. 7 illustrate an integration of AIS and indoor GIS bays with a dual mode compact bus, in accordance with an embodiment of the present subject matter; and
[0060] Fig. 8 illustrate a patented integration of AIS and mixed installation GIS bays with a dual mode compact bus, in accordance with an embodiment of the present subject matter.
[0061] 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
[0062] 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.
[0063] 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.
[0064] 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.
[0065] 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.
[0066] 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.
[0067] 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.
[0068] Fig. 1 illustrates a dual mode compact gas insulated bus (100) according to one embodiment of the invention.
[0069] Referring to Fig. 1,2,3 4 and 5 together, in an embodiment, a compact gas insulated bus bar comprises of three bus bars (111) in a single grounded metallic enclosure (104). The three bus bars (111) are made of high electrical conductivity material to enable efficient current flow with minimal power loss and is insulated from the grounded metallic enclosure (104) with designed insulating gas density. A rib insulator (119) is made of filled epoxy material and compatible to insulating gas. The rib insulator (119) holds each of the bus bars (111) through a plug-in adapter (108) in such a configuration where each of the bus bar (111) is placed at the vertices of an equilateral triangle or right angled or any arbitrary angle in a grounded metallic enclosure (104) filled with SF6 gas at designed density. The plug-in adapter (108) is made of high electrical conductivity material makes the electrical connection between the rib insulator (119) and the bus bars (111). Each of the bus bar (111) is ended with a termination shield or flexible HT shield (107), which controls the electric stress between the bus bars (111) and the bus bars to the grounded enclosure (104).
[0070] The compact bus bar is alternatively used as bus bar for air insulated switchgear and for gas insulated switchgear. In case, it is required only for the GIS, same compact bus can be used without extending connections to open air. The scheme is divided into three parts. One part is air insulated switchgear of multiple bays with single or double bus arrangement. The second one is gas insulated switchgear of multiple bays with single or double bus arrangement. To integrate these two switchgear, a module has been proposed as the third part. The module is named as dual mode compact gas insulated bus (116a). This compact bus is used as gas insulated bus (102a) for gas insulated switchgear and it also acted as extended air insulated bus of air insulated switchgear. The proposed module of dual mode compact gas insulated bus (116a) acts as an interface module between gas insulated switchgear bays and air insulated switchgear bus. Precisely, the bays of AIS (101) can be extended by integrating GIS bays (102) directly to the AIS bus (101a) by using proposed dual mode compact gas insulated bus (116a). The proposed dual mode gas insulated bus has the grounded metallic enclosure (104) which encloses the bus bars (111) consists of two sets of ports. One set of ports are called as AIS side Ports (105) and another set of ports are called GIS side ports (106). Precisely, there are set of ports on grounded enclosure to commensurate high voltage connection to air insulated switchgear bus and set of ports to commensurate high voltage connection to gas insulated switchgear. The AIS side ports (105) are used to commensurate to other insulating media like gas or liquid or solid or combination of them. The angularly disposed ports (105,) on metallic enclosure (104) are made radially at a designed angle to keep electrical isolation between phase-phase and phase-ground of insulated terminal connections. The grounded enclosure has unique design so that it acts as air insulated bus (101a) as well as gas insulated bus (102a). The Proposed scheme claims that the footprint for one bay of switchgear is only 20 to 30 % of hybrid GIS bays if we install in multiple numbers. At present, one or two bays of extension can be appropriate with hybrid GIS bays. Beyond that proposed scheme helps in reduction of footprint which is very much needed in existing conventional air insulated substations. The proposed dual mode compact gas insulated bus (116a) can also be possible with segregated phase configuration. In that case, three independent enclosed bus bars are required for each bus of switchgear.
[0071] Fig. 2 illustrate an angled-cum-straight terminal and straight terminal of proposed dual mode bus bar system. An angled-cum-straight terminal (109) and a straight-cum-straight terminal (110) transfers current from the bus bar (111) to high voltage terminal of other insulation media or gas insulated module through a flexible contact (112) covered by a HT integrated shield (113). The angled-cum-straight terminal (109), the straight-cum-straight terminal (110), the flexible contact (112) and the flexible contact shields or the HT integrated shield (113) are made of high electrical conductivity material to maintain efficient current transfer with minimal power losses. The straight-cum-straight terminal (110) extends the electrical connection orthogonally from the bus bar (111) to other insulation media/module of gas insulated switchgear through a support insulator (117). The insulating medium can be gas or liquid or solid or combination of them. Whereas the angled-cum-straight terminal (109) extend the electrical connection radially at a designed angle from the bus bars (111) to other insulation media and other modules of gas insulated switchgear through the support insulators (117) simultaneously. The angled-cum-straight terminals (109) are profiled at a designed angle equal to the angle of angular ports (105, 106) on a grounded metallic enclosure (104). This is to achieve the uniform electric stresses around the angled-cum-straight terminal (109), between the bus bars (111) and between the bus bar (111) and the grounded metallic enclosure (104). The angled-cum-straight terminal (109) and the straight-cum-straight terminal (110) provide the flexibility in design. These terminals shall rotate radially at any desired angle based on the requirement. An epoxy support insulator (117) is used to support the flexible contact (112) and to commensurate high voltage connection to other insulation medium or to other gas insulated switchgear modules.
[0072] Fig. 3 illustrates the flexible contact (112) with HT integrated shield (113) proposed as part of patent. The epoxy support insulator (117) consists of three parts. The first one is HT insert (121). The second one is low tension (LT) insert (122). The third one is casted epoxy body (123). The single phase support insulator can be fastened to the tubular grounded enclosure (104). The HT integrated shield (113) has a cylindrical / spherical profile and its profile / radius depends on the operating voltage for which support insulator (117) is used. The HT integrated shield (113) is fastened electrically to high voltage (HV) conductor / bus bar (111) through flexible contact (112). The flexible contact (112) provides low contact resistance current transfer from HT insert (10A) to bus bar (111). The HT integrated shield (113) connected to the flexible contact (112) limits highest electric field levels well below permissible levels.
[0073] Fig. 4 illustrate a dual mode compact bus arrangement with rib insulators and terminal arrangement. The rib insulator (119) holds each of the bus bars (111) through plug-in adapter (108) in such a configuration where each bus bar (111) is placed at the vertices of an equilateral triangle or right angled or any arbitrary angle in a grounded metallic enclosure (104) filled with SF6 gas at designed density. The rib insulator (119) consists of three parts. First one is HT insert (124). Second one is low tension (LT) insert (120). The third one is epoxy body (126). The Rib insulator body (126) is always on the floating voltage so that its creepage and the gas gap between epoxy body (126) and grounded enclosure (104) shall be sufficient enough to limit the surface stress on epoxy body (126). Similarly, the compact LT shield (125) is profiled in such a way that the electrostatic field level at tri-junction point (junction of gas, metal and epoxy insulation) is much less than that E-field level on the insulator body. The three phase gas insulated bus bar (111) with smallest possible distance between bus and the grounded enclosure can be selected with this type of rib insulator (119) arrangement. Here rib insulator (119) is used to support each phase of HT bus bar (111) from the grounded enclosure (104) at two points (surface area can be selected based on requirements) unlike post insulator which is at one-point support from grounded enclosure (104). Only one rib insulator (119) on either side of bus bar (111) is good enough to support of each phase of bus bar at a particular location unlike multiple post insulators. Further, to adopt multiple post insulators, it is essential to keep more gas gap from bus bar (111) to grounded enclosure (104).
[0074] Fig. 5 illustrate a dual mode compact bus and integration to AIS and GIS switchgear
[0075] The high voltage connection from bus bar (111) is extended to AIS side switchgear (101) through support insulator (117), angled enclosure (114) and a gas-to-air bushing (115). The high voltage connection from bus bar (111) is extended in two possible ways. One is dual mode compact gas insulated bus (116a) is extended in the form of gas insulated enclosure inside building as gas insulated bus (102a) where it can be used to extend as any number of gas insulated switchgear bays (102). Alternatively, the high voltage connection simultaneously can be extended to gas insulated switchgear equipment (102) i.e. disconnector switch, earthing switch, gas circuit breaker etc. through support insulator (117). This scheme is designed for outdoor GIS. A dual mode compact bus bar module which can be simultaneously used as extension of air insulated bus (101a) of the AIS and can be extended as gas insulated bus (102a) as well as gas insulated switchgear bay in case of mixed installation type GIS (some bays are indoor (102) and some bays are outdoor type (118). The proposed high voltage connection is a unique one that a single terminal i.e. either angled-cum-straight terminal (109) or straight-cum-straight terminal (110) is extended from bus bar to both air insulated switchgear side bus (101a) and gas insulated switchgear bays (102). Angled enclosures (114) are arranged in series to AIS ports (105) to commensurate HV connection to gas-to-air bushing (115). These angled enclosures (114) are of the same design for all three phases and they shall be rotated depending on the required phase distance with air insulation. Precisely, all three angled enclosures (114) are mounted in a predefined angle but design of all three are one and same. The HT conductor of the angled enclosure (114) also follows the same orientation to maintain same insulation distance between enclosure and HT conductor. In case of second bus, it is to be maintained at suitable insulation clearance in air and connect to existing second bus of AIS (07B). Second dual mode compact bus (116b) runs parallel to first bus (116a) and enter the GIS building. In GIS building or in open yard these compact buses are used as BUS I and BUS II for GIS switchgear bays.
[0076] Fig. 6 illustrates a dual mode compact bus for multiple bays with suitable bellow or expansion element (128).
[0077] This integration is required to establish multiple bays in electrical substations. Each GIS switchgear bay is connected to double bus or single bus with components like bus disconnector, earthing switch, gas circuit breaker, maintenance earthing switch, feeder disconnector switch, fast acting earthing switch, surge arrester etc. The GIS feeder can be connected to gas insulated bus duct or XLPE cable and not necessarily to be overhead transmission line. These extensions can also act as incomers for predefined substations.
[0078] Fig. 7 illustrate the integration of AIS and indoor GIS bays with a dual mode compact bus.
[0079] Fig. 8 illustrate the integration of AIS and mixed installation type GIS bays with a dual mode compact bus.
[0080] 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.