Description:

FIELD OF THE INVENTION

Embodiments of the invention in general relates to the technical field of power equipment, more particularly, to an integrated Test Tank of Gas Insulated Switchgear, GIS, which is an integration of several tanks, in which several Routine Test or Type Tests can be performed in a single tank.

BACKGROUND OF THE INVENTION

In any Switchgear, many routine tests are performed to ensure the quality of the product manufactured. Validation Tests are also performed to ensure the durability, endurance of any modified parts/assembly. This may include tests like PD Testing, BIL, Mechanical Endurance, Gas leakage testing of O rings, flanges and many more.

Earlier, to conduct any validation test/routine test/type test on any part/assembly, GIS whole panel has to be erected and assembled. This indirectly brings cost implications and as the whole panel needs to be assembled, so it was also time consuming and prone to some errors.

Reference is being made to CN203326461U, disclosing an arrangement structure of GIS apparatus. The arrangement structure of the GIS apparatus comprises a circuit breaker, a current transformer, a lightning arrester, a cable pot, a three-phase voltage transformer and three-station isolation grounding switches, wherein the circuit breaker is connected with the current transformer. The arrangement structure of the GIS apparatus is characterized by further comprising a tee joint, wherein the branch pipe of the tee joint is oriented downwards and is connected with the cable pot, the two ends of the main pipe of the tee joint are respectively connected with the three-station isolation grounding switch, one three-station isolation grounding switch is connected with the current transformer, the upper part of the other three-station isolation grounding switch is connected with the three-phase voltage transformer, and the lower part of the other three-station isolation grounding switch is connected with the lightning arrester. The arrangement structure of the GIS apparatus is high in stability performance and facilitates the observation of inspection tour personnel; the overall cost is not increased and the workshop assembling and on-site tamping tests are facilitated; and the product's long-time operation stability is guaranteed and the beauty of a secondary wire duct arrangement is improved. CN203326461U is related with an arrangement of various electrical components such as CT, PT, surge arrestors etc within a Gas insulated Switch gear. It focuses on how the CT PTs etc are assembled within GIS. Whereas the present disclosure focuses on testing arrangement with GIS where different types of Bushings etc can be tested and validated.

Reference is being made to CN204479704U, disclosing a kind of test casing of GIS terminal test unit. This sleeve pipe comprises insulating cylinder body, high pressure retraction mechanism, grounded shield electrode and ground connection flange; Described ground connection flange is connected with one end of insulating cylinder body, and high pressure retraction mechanism is connected with the other end of insulating cylinder body; Described grounded shield electrode is arranged on the inwall of insulating cylinder body, and with ground connection Flange joint; One end of described insulating cylinder body and ground connection Flange joint is provided with towards the other end of insulating cylinder body the test cavity stretched into for GIS terminal, and during work, described test chamber body forms the test cavity of sealing. This casing safety is reliable, low-profile, structure is simple, it is convenient to install and use, and can carry out completion withstand voltage test, effectively can improve accuracy, the validity and reliability of test, be conducive to extensive penetration and promotion GIS terminal and cable line. CN204479704U is basically a test casing for GIS Test Terminals only. Whereas the present disclosure focuses on testing arrangement with GIS where different types of Bushings etc can be tested and validated.

In view of the prior art, there is a dire need of a Test Tank which will curb down this issue and serve all the above the purpose but remain risk free, cost buster & transportation friendly.

SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

According to one aspect of the present invention, an integrated test tank (13) of Gas Insulated Switchgear, GIS, the tank comprising: an insulating SF6 gas filled leak proof enclosure having a geometrical shape with a plurality of surfaces, and a plurality of legs on at least one surface of the test tank for erecting the test tank, said enclosure comprising: a plurality of mounting ports on at least one surface of the test tank, adapted to receive a plurality of parts, subassemblies, assemblies for electrical and mechanical testing and validation, at the same time.

Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which:

Fig. 1 illustrates an integrated test tank of Gas Insulated Switchgear, GIS, for BIL, PFHV, PD Testing of Long Bushing, Short Bushing, Plugin Bushing in an integrated Test Tank, according to an embodiment of the present invention.
Fig. 2 illustrates an integrated test tank of Gas Insulated Switchgear, GIS, with an arrangement of copper Links and Inner-cone Bushing used for Mechanical and Electrical testing, according to an embodiment of the present invention.
Fig. 3 illustrates an integrated test tank of Gas Insulated Switchgear, GIS, showing assembly of DS Mechanism & PT Switch Mechanism on Integrated Test Tank, according to an embodiment of the present invention.
Fig. 4 illustrates an integrated test tank of Gas Insulated Switchgear, GIS, having an End Flange, Cover, Bursting Disk Mounting Arrangement, according to an embodiment of the present invention.
Fig. 5 illustrates an integrated test tank of Gas Insulated Switchgear, GIS, showing Seal Welded in Integrated Test Tank, according to an embodiment of the present invention.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.

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 various embodiments belong. Further, the meaning of terms or words used in the specification and the claims should not be limited to the literal or commonly employed sense, but should be construed in accordance with the spirit of the disclosure to most properly describe the present disclosure.

The terminology used herein is for the purpose of describing particular various embodiments only and is not intended to be limiting of various 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” and/or “comprising” used herein specify the presence of stated features, integers, steps, operations, members, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, components, and/or groups thereof. Also, Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

The present disclosure will now be described more fully with reference to the accompanying drawings, in which various embodiments of the present disclosure are shown. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the various embodiments set forth herein, rather, these various embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the present disclosure. Furthermore, a detailed description of other parts will not be provided not to make the present disclosure unclear. Like reference numerals in the drawings refer to like elements throughout.

The subject invention lies in an integrated test tank which is a simple integration of several tank designs achieved in a single tank. The tank can be erected along two-planes. In an embodiment, the single tank can be used as two different tanks of different dimensions. The compartment is a steel tank welded assembly of typical thickness of 3mm consisting of various internal components.

According to an embodiment, after assembling all the necessary internal components of the switchgear which needs to be tested, inside the welded tank, the door is closed with the help of silicone O-rings and insulating gas is filled with certain amount of pressure required to maintain the specified insulation level inside the tank. Less components makes it easier to assemble/disassemble and also makes it more reliable. This overall design serves various functions mention below.

According to an embodiment of the present invention, an integrated test tank comprising an insulating SF6 gas filled leak proof enclosure having a geometrical shape with a plurality of surfaces, and a plurality of legs on at least one surface of the test tank for erecting the test tank, said enclosure comprising: a plurality of mounting ports on at least one surface of the test tank, adapted to receive a plurality of parts, subassemblies, assemblies for electrical and mechanical testing and validation, at the same time.

In the existing systems, incoming inspection/Quality testing of long bushing, insulators, partition bushings etc was done in oil. But, in actual service bushing/insulators would be in partial SF6 and air condition. This integrated test tank helps to simulate the actual service conditions during incoming and quality inspection. Also, for all other electrical and mechanical testing mentioned below, the whole switchgear was erected which has impact on cost as well as lead time to complete the test. The Integrated test tank of the present invention is a compact version in which various parts/subassemblies/ assemblies can be mounted and validated at the same time.

According to an embodiment, as shown in Fig. 1, the Integrated Test tank (13), has a plurality of legs in one plane and a plurality of legs in another plane. In an exemplary implementation, the tank has four legs in one plane and four legs in another plane. This facilitates erecting the test tank in 2 or more planes. As the tank is erected in different planes, different parts, assemblies, subassemblies, mechanism etc can be assembled, tested, and validated in this single tank.
According to an embodiment, the integrated test tank facilitates electrical testing, as below.

Electrical Testing:
1. Partial Discharge (PD) Testing on Long Bushing, Short Bushing , Cable, Plug in Bushing:
As shown in Fig. 1, Long Bushing (1), Short Bushing (2), Cable, Plug in Bushing (3) can be mounted on their specified hardware ports/protrusions in the test tank. Copper links (5) are used to connect the bushing with a Disconnector Switch mechanism (7). After the assembly of all the bushings, copper links (5), mechanism etc, a cover (4) having an O ring and sealant is used to seal the tank. SF6 gas is filled in this leak proof tank. Then, Partial Discharge test voltage is given to the conductor of the bushing and the tank is connected to Earth. In this way Partial discharge test in performed on the bushings etc with the help of integrated Test Tank. This test finds the deterioration or failure due to internal discharges caused in the composite insulation of the bushing. This is done by using an internal or partial discharge arrangement.
2. Basic Insulation level Testing: Similar assembly can be done while different shapes of copper links can be used to test the basic insulation level of the tank. This integrated test tank is designed to study Basic Insulation levels upto 180kVp in Normal condition and 195kVp in Isolating Condition, also having PFHV level of 80kV for 1 min.
According to an embodiment, the integrated test tank facilitates mechanical testing, as below.
Mechanical Testing:
1. Mechanical Endurance for Disconnector Switch Mechanism and Module: For this testing, DS Mechanism (7), copper links (5), Bushing and cover (4) are required. As shown in Fig. 3, the DS mechanism (7) is mounted outside on the front sheet of the tank and it is connected to the copper links (5) inside the tank. The tank is sealed with the help of the cover (4). Mechanism endurance Test of different categories like M0 , M1, M2 class can be performed using this integrated test tank.
2. Validation of parts, Subassemblies like inner cone bushing, PT switch mechanism (8): As explained above, in this similar way validation of different parts, sub assemblies can be performed.
3. Pressure withstand test of Tank: In pressure withstand test, the tank is completely sealed using covers, bushing etc. Air is filled inside the tank using NRV which results in increase of pressure inside the tank. As shown in Fig. 4, a Bursting disk (9) is mounted on cover (4). This Integrated test tank can be used to check operating or bursting pressure of different bursting disks.
4. O ring , seal, end flange, coupling flange Leakage testing: O rings (10), flanges (11) and sealants (12) are important component to make switchgear leak proof. Quality testing of the same can be done using this integrated Test tank.
5. Molecular sieve Testing: Molecular sieve is used to absorb water content from the SF6 gas inside the tank. Water absorption capacity of this molecular sieve can be tested using test tank by checking the dew point of SF6.
In exemplary implementations, the integrated tank of the present disclosure is used for PD Testing on Long/Short Cable Bushing, mechanical endurance of DS Module/DS Mechanism, PD Testing of Plugin Bushing, BIL Testing of DS Module with Plugin Bushing, Validation of Bus PT switch, Validation of size-2 inner cone bushing/VT, Validation of secondary bushing, Pressure Withstand Test of Tank and Manometer validation, O-ring/Seal Leakage Testing, and the like.

Some of the non-limiting advantages of the integrated test tank of Gas Insulated Switchgear are:

1. Economical and replaces costlier panel.
2. Reduces risk of assembly errors in Injection Panel.
3. Assembly and coupling of the Test Tank is more convenient and reliable.
4. Transportation and storage are easier and takes less space.

Although an integrated test tank of Gas Insulated Switchgear has been described in language specific to structural features, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific methods or devices described herein. Rather, the specific features are disclosed as examples of implementations of an integrated test tank of Gas Insulated Switchgear.

Construction: Few of the major components & assemblies which this compartment is comprises of are:
1. Long Bushing
2. Short Bushing
3. Plugin Bushing
4. Cover
5. Copper links
6. Inner cone bushing
7. DS mechanism
8. PT switch Mechanism
9. Bursting Disk
10. O rings
11. End Flange
12. Sealant
13. Tank
, Claims: WE CLAIM:

1. An integrated test tank (13) of Gas Insulated Switchgear, GIS, the tank comprising:
an insulating SF6 gas filled leak-proof enclosure having a geometrical shape with a plurality of surfaces, and a plurality of legs on at least one surface of the test tank for erecting the test tank, said enclosure comprising:
a plurality of mounting ports on at least one surface of the test tank, adapted to receive a plurality of parts, subassemblies, assemblies for electrical and mechanical testing and validation, at the same time.
2. The test tank as claimed in claim 1, wherein the test tank comprises six surfaces, said surfaces being aligned to each other at an angle to form different planes.
3. The test tank as claimed in claim 1, wherein the test tank comprises: a first surface adapted to mount at least one long bushing (1), and at least one short bushing (2); a second surface adapted to receive at least one plug in bushing (3); a cover with silicone O rings (10) forming one of the surfaces of the test tank; and a sealant (12) to seal the test tank (13), wherein the bushings are mechanically coupled to a Disconnector Switch, DS mechanism (7) with copper links (5), wherein the DS mechanism (7) is mounted outside on a front surface (sheet) of the tank, and is connected to copper links (5) inside the tank.
4. The test tank as claimed in claim 1, wherein during Partial Discharge, PD, testing of the bushings, the partial discharge test voltage is conducted to the conductor of the bushing and the tank is connected to Earth.
5. The test tank as claimed in claim 1, wherein during Basic Insulation Level, BIL, testing, different shapes of copper links are used to test the basic insulation level of the tank, and the test tank is adapted to study BIL upto 180kVp in Normal condition and 195kVp in Isolating Condition.
6. The test tank as claimed in claim 1, wherein during mechanical endurance testing for DS mechanism, different categories like M0, M1 , M2 class are performed.
7. The test tank as claimed in claim 1, wherein the tank is adapted to: validate parts, subassemblies like inner cone bushing, and PT switch mechanism (8); test the leakage of the O rings (10), sealant (12), end flange (11), coupling flange; and test water absorption capacity of a molecular sieve placed to absorb water content from the SF6 gas inside the tank, by checking the dew point of SF6.
8. The test tank as claimed in claim 1, wherein during pressure withstand test, the tank is completely sealed using covers, bushing; air is filled inside the tank increasing the pressure inside the tank; and a bursting disk (9) is mounted on the cover (4) to check operating or bursting pressure of different bursting disk.
9. The test tank as claimed in claim 1, wherein the tank comprises of four legs in one plane and four legs in another plane to facilitate erecting the test tank
in two or more planes.
10. An electrical and mechanical testing method performed by an integrated test tank (13) of Gas Insulated Switchgear, GIS, as claimed in any one of claims 1-9, to ensure quality of product manufactured.

Dated this 21st day of April 2022

Abhishek Sen
IN/PA Reg No: 980
Of S. MAJUMDAR & CO.
(Applicant’s Agent)