Description: TECHNICAL FIELD
[0001] The present disclosure relates to the field of gas-insulated switchgear. More particularly the present disclosure relates to a fail-safe mechanism for earthing connecting cable coupled between a plurality of gas-insulated switchgear.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] A typical gas-insulated switchgear (GIS) board consists of an incomer and multiple outgoing panels. Multiple GIS boards can be interconnected using connecting cables. For connecting multiple GIS boards, an outgoing terminal of a first GIS can be electrically coupled with the incoming terminal of another (second) GIS. However, in case of any fault in the connecting cables, it is required to earth the connecting cables first since there can be a charge accumulated in the connecting cables which can cause injury to maintenance personnel. An ideal way to do this is to electrically isolate the disconnector of the first GIS and then earth the connecting cable through the disconnector of the second GIS. But while earthing the connecting cables through the disconnector of the second GIS, the disconnector is supposed to be kept in the electrical isolation condition only. But there are chances of accidental or un-intentional switching, from the electrical isolation condition, of the disconnector of the first GIS, which is undesired.
[0004] There is, therefore, a need for a fail-safe mechanism for earthing the connecting cables, which avoids any possibility of accidental or un-intentional switching of the disconnector of the first GIS while earthing the connecting cables.

OBJECTS OF THE PRESENT DISCLOSURE
[0005] Some of the objects of the present disclosure, which at least one embodiment herein satisfy are as listed herein below.
[0006] It is an object of the present disclosure to provide a fail-safe mechanism for earthing a connecting cable connecting the gas-insulated switchgears, which avoids any accidental or un-intentional line-to-earth fault.
[0007] It is an object of the present disclosure to provide a fail-safe mechanism for earthing a connecting cable connecting the gas-insulated switchgears, which is easy to used and install.
[0008] It is an object of the present disclosure to provide a fail-safe mechanism for earthing a connecting cable connecting the gas-insulated switchgears, which has less maintenance cost.
[0009] It is an object of the present disclosure to provide a fail-safe mechanism for earthing a connecting cable connecting the gas-insulated switchgears, which is cost-effective and efficient.

SUMMARY
[0010] The present disclosure relates to the field of gas-insulated switchgear. More particularly the present disclosure relates to a fail-safe mechanism for earthing connecting cable coupled between a plurality of gas-insulated switchgear.
[0011] An aspect of the present disclosure pertains to a fail-safe mechanism for earthing a connecting cable, coupled between an outgoing terminal of a first gas-insulated switchgear and an incoming terminal of a second gas-insulated switchgear. The fail-safe mechanism includes a first rotating cam arrangement configured with the first gas-insulated switchgear. The first cam arrangement includes a first rotating member, having a first end and a second end with a first tapered profile, configured to be rotated between a first position and a second position, and the first rotating member is configured to rotate, from the first end, between the first position and the second position using a castle key. A first member, having a third end and a fourth end, slidably configured with a first rotational plate of the first gas-insulated switchgear. On rotating the first rotating member to the second position, the first member is pushed, from the third end, by the first tapered profile facilitating sliding of the fourth end into a first slot of the first rotating plate.
[0012] In an aspect, sliding the fourth end into the first slot may facilitate restricting a first disconnector of the first gas-insulated switchgear at an electrical isolation condition such that the first disconnector is prevented from switching to any of electrically ON condition and electrically earthed condition.
[0013] In an aspect, the first disconnector may be electrically coupled with input voltage.
[0014] In an aspect, the castle key may be configured to be detached from the first end when the first rotating member is at the second position only.
[0015] In an aspect, the fail-safe mechanism may include a second rotating cam arrangement operatively configured with the second gas-insulated switchgear. The second rotating cam arrangement includes a second rotating member, having a fifth end and a sixth end with a second tapered profile, configured to be rotated, after detaching the castle key, between a third position and a fourth position. The second rotating member may be configured to rotate, from the fifth end, between the third position and the fourth position using the castle key. A second member, having a seventh end and an eight end, slidably configured with a second rotational plate of the second gas-insulated switchgear. On rotating the second rotating member to the fourth position, the second member is pushed, from the seventh end, by the second tapered profile facilitating sliding the eighth end out of a second slot of the second rotating plate.
[0016] In an aspect, the second gas-insulated switchgear may include a second disconnector configured with electrical earth.
[0017] In an aspect, sliding the eighth end out of a second slot of the second rotating plate may facilitate rotation of the second rotational plate to a pre-defined degree such that the second disconnector is electrically coupled with the electrical earth to earth the connecting cable.
[0018] In an aspect, the eighth end may be slid into the second slot when the second rotating member is at the third position such that the second rotational plate is prevented from rotating till the pre-defined angle such that the second disconnector is electrically decoupled from the electrical earth.
[0019] 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 DRAWINGS
[0020] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure.
[0021] In the figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
[0022] FIG. 1 illustrates an exemplary representation of a signal line diagram of coupling GISs using connecting cable, in accordance with an embodiment of the present disclosure.
[0023] FIG. 2A-B illustrates an exemplary representation of the fail-safe mechanism for upstream (first) gas-insulated switchgear, in accordance with an embodiment of the present disclosure.
[0024] FIG. 3A illustrated an exemplary representation of the first rotating member at the first position, in accordance with an embodiment of the present disclosure.
[0025] FIG. 3B illustrated an exemplary representation of the first rotating member at the second position, in accordance with an embodiment of the present disclosure.
[0026] FIG. 4A-B illustrates an exemplary representation of the fail-safe mechanism for downstream (second) gas-insulated switchgear, in accordance with an embodiment of the present disclosure.
[0027] FIG. 5A illustrated an exemplary representation of the first rotating plate at the different electrical conditions, in accordance with an embodiment of the present disclosure.
[0028] FIG. 5B illustrated an exemplary representation of the second rotating plate at the different electrical conditions, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0029] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered 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.
[0030] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
[0031] The present disclosure relates to the field of gas-insulated switchgear. More particularly the present disclosure relates to a fail-safe mechanism for earthing connecting cable coupled between a plurality of gas-insulated switchgear.
[0032] The present disclosure elaborates upon a fail-safe mechanism for earthing a connecting cable, coupled between an outgoing terminal of a first gas-insulated switchgear and an incoming terminal of a second gas-insulated switchgear. The first gas-insulated switchgear can be referred to upstream GIS and the second gas-insulated switchgear can be referred to downstream GIS. The fail-safe mechanism includes a first rotating cam arrangement configured with the first gas-insulated switchgear. The first cam arrangement includes a first rotating member, having a first end and a second end with a first tapered profile, configured to be rotated between a first position and a second position, and the first rotating member is configured to rotate, from the first end, between the first position and the second position using a castle key. A first member, having a third end and a fourth end, slidably configured with a first rotational plate of the first gas-insulated switchgear. On rotating the first rotating member to the second position, the first member is pushed, from the third end, by the first tapered profile facilitating sliding of the fourth end into a first slot of the first rotating plate.
[0033] In an embodiment, sliding the fourth end into the first slot can facilitate restricting a first disconnector of the first gas-insulated switchgear at an electrical isolation condition such that the first disconnector is prevented from switching to any of electrically ON condition and electrically earthed condition.
[0034] In an embodiment, the first disconnector can be electrically coupled with input voltage.
[0035] In an embodiment, the castle key can be configured to be detached from the first end when the first rotating member is at the second position only.
[0036] In an embodiment, the fail-safe mechanism can include a second rotating cam arrangement operatively configured with the second gas-insulated switchgear. The second rotating cam arrangement includes a second rotating member, having a fifth end and a sixth end with a second tapered profile, configured to be rotated, after detaching the castle key, between a third position and a fourth position. The second rotating member can be configured to rotate, from the fifth end, between the third position and the fourth position using the castle key. A second member, having a seventh end and an eight end, slidably configured with a second rotational plate of the second gas-insulated switchgear. On rotating the second rotating member to the fourth position, the second member is pushed, from the seventh end, by the second tapered profile facilitating sliding the eighth end out of a second slot of the second rotating plate.
[0037] In an embodiment, the second gas-insulated switchgear can include a second disconnector configured with electrical earth.
[0038] In an embodiment, sliding the eighth end out of a second slot of the second rotating plate can facilitate rotation of the second rotational plate to a pre-defined degree such that the second disconnector is electrically coupled with the electrical earth to earth the connecting cable.
[0039] In an embodiment, the eighth end can be slid into the second slot when the second rotating member is at the third position such that the second rotational plate is prevented from rotating till the pre-defined angle such that the second disconnector is electrically decoupled from the electrical earth.
[0040] FIG. 1 illustrates an exemplary representation of a signal line diagram of coupling GISs using connecting cable, in accordance with an embodiment of the present disclosure.
[0041] FIG. 2A-B illustrates an exemplary representation of the fail-safe mechanism for upstream (first) gas-insulated switchgear, in accordance with an embodiment of the present disclosure.
[0042] FIG. 3A illustrated an exemplary representation of the first rotating member at the first position, in accordance with an embodiment of the present disclosure.
[0043] FIG. 3B illustrated an exemplary representation of the first rotating member at the second position, in accordance with an embodiment of the present disclosure.
[0044] FIG. 4A-B illustrates an exemplary representation of the fail-safe mechanism for downstream (second) gas-insulated switchgear, in accordance with an embodiment of the present disclosure.
[0045] FIG. 5A illustrated an exemplary representation of the first rotating plate at the different electrical conditions, in accordance with an embodiment of the present disclosure.
[0046] FIG. 5B illustrated an exemplary representation of the second rotating plate at the different electrical conditions, in accordance with an embodiment of the present disclosure.
[0047] As illustrated, a fail-safe mechanism for earthing a connecting cable 400, coupled between an outgoing terminal of a first gas-insulated switchgear 200 and an incoming terminal of a second gas-insulated switchgear 300 can include a first rotating cam arrangement configured with the first gas-insulated switchgear 200. The first cam arrangement can include a first rotating member 102 having a first end 102-1 and a second end 102-2 with a first tapered profile. The first rotating member 102 can be configured to be rotated between a first position and a second position. The first rotating member 102 can be configured to rotate, from the first end 102-1, between the first position and the second position using a castle key. The castle key can be entered into a first cavity in a first facia of the first gas-insulated switchgear 200. The castle key can be operatively coupled with the first end 102-1 through the cavity. The castle key can be configured to be detached from the first end 102-1 (or the cavity) when the first rotating member 102 is at the second position only
[0048] In an embodiment, a first member 104 can include a third end 104-1 and a fourth end 104-2. The first member 104 can be slidably configured with a first rotational plate 202 of the first gas-insulated switchgear 200. On rotating the first rotating member 102 to the second position, the first member 104 can be pushed, from the third end 104-1, by the first tapered profile facilitating sliding of the fourth end 104-2 into a first slot 202-1 of the first rotating plate 202. When the fourth end slides into the first slot 202-1, the first rotational plate is locked and is prevented from any further rotation, in any direction, till the fourth end is slid out of the first slot 202-1. In this way, the first disconnector of the first gas-insulated switchgear 200 is locked in the electrical isolation condition (also known as electrically OFF condition). The electrically OFF condition can correspond to when the disconnector is decoupled from input supply. Ideally, the first disconnector of the first gas-insulate switchgear can be electrically coupled with input voltage.
[0049] In an embodiment, the fail-safe mechanism can include a second rotating cam arrangement operatively configured with the second gas-insulated switchgear 300. The second rotating cam arrangement can include a second rotating member 108 having a fifth end 108-1 and a sixth end 108-2 with a second tapered profile. The second rotating member 108 can be configured to be rotated, after detaching the castle key from the first cavity, between a third position and a fourth position. The second rotating member 108 can be configured to rotate, from the fifth end 108-1, between the third position and the fourth position using the castle key. The castle key can be entered in a second cavity of the second gas-insulated switchgear 300. A second member 110 can include a seventh end 110-1 and an eighth end 110-2. The second member 110 can be slidably configured with a second rotational plate 302 of the second gas-insulated switchgear 300. On rotating the second rotating member 108 to the fourth position, the second member 110 can be pushed, from the seventh end 110-1, by the second tapered profile facilitating sliding the eighth end 110-2 out of a second slot 302-1 of the second rotating plate 302. The second slot 302-1 can be a slot having a pre-defined dimension such that when the eight end 110-2 is inside the second slot 302-1, the second rational plate 302 can be allowed to rotate corresponding to any of electrically ON condition and electrically OFF condition only. But when the eighth end 110-2 is slid out of the second slot 302-1, then only the second rotation plate 302 can be allowed to rotate corresponding to the electrical earth condition of a second disconnector of the second gas-insulated switchgear 300. The second disconnector can be electrically configured with electrical earth.
[0050] In an embodiment, sliding the eighth end out of a second slot of the second rotating plate can facilitate rotation of the second rotational plate to a pre-defined degree such that the second disconnector is electrically coupled with the electrical earth to earth the connecting cable. The pre-define degree can correspond to the dimension of the second slot 302 till which the rotation plate is allowed to rotate. The eighth end 110-2 can be slid into the second slot 302-1 when the second rotating member 108 is at the third position such that the second rotational plate 302 can be prevented from rotating till the pre-defined angle such that the second disconnector is electrically decoupled from the electrical earth.
[0051] The present disclosure pertained to a fail-safe mechanism to electrically earth a connecting cable configured between the outgoing terminal of the first gas-insulated switchgear and the second gas-insulated switchgear. The proposed fail-safe mechanism prevents any possibility of line-to-earth fault. Since the second disconnector is allowed to be earthed only when the first disconnector is electrically isolated from the input supply. In this way, any accidental or un-intentional line-to-earth can be avoided. The proposed mechanism is very easy to use and install since no complex equipment or sensors are used in it. Also, the maintenance cost of the proposed mechanism is less since very simple components are used in it. Thus, the overall cost is also less.
[0052] Moreover, in interpreting the specification, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C ….and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
[0053] 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.

ADVANTAGES OF THE INVENTION
[0054] The proposed invention provides a fail-safe mechanism for earthing a connecting cable connecting the gas-insulated switchgears, which avoids any accidental or un-intentional line-to-earth fault.
[0055] The proposed invention provides a fail-safe mechanism for earthing a connecting cable connecting the gas-insulated switchgears, which is easy to used and install.
[0056] The proposed invention provides a fail-safe mechanism for earthing a connecting cable connecting the gas-insulated switchgears, which has less maintenance cost.
[0057] The proposed invention provides a fail-safe mechanism for earthing a connecting cable connecting the gas-insulated switchgears, which is cost-effective and efficient.

, Claims: 1. A fail-safe mechanism for earthing a connecting cable (400), coupled between an outgoing terminal of a first gas-insulated switchgear (200) and an incoming terminal of a second gas-insulated switchgear (300), the fail-safe mechanism comprising:
a first rotating cam arrangement configured with the first gas-insulated switchgear (200), and the first cam arrangement comprises:
a first rotating member (102), having a first end (102-1) and a second end (102-2) with a first tapered profile, configured to be rotated between a first position and a second position, wherein the first rotating member (102) is configured to rotate, from the first end, between the first position and the second position using a castle key; and
a first member (104), having a third end (104-1) and a fourth end (104-2), slidably configured with a first rotational plate (202) of the first gas-insulated switchgear (200), wherein on rotating the first rotating member (102) to the second position, the first member (104) is pushed, from the third end (104-1), by the first tapered profile facilitating sliding of the fourth end (104-2) into a first slot (202-1) of the first rotating plate.

2. The fail-safe mechanism as claimed in claim 1, wherein sliding the fourth end (104-2) into the first slot (202-1) facilitates restricting a first disconnector of the first gas-insulated switchgear (200) at an electrical isolation condition such that the first disconnector is prevented from switching to any of electrically ON condition and electrically earthed condition.

3. The fail-safe mechanism as claimed in claim 1, wherein the first disconnector is electrically coupled with input voltage.
4. The fail-safe mechanism as claimed in claim 1, wherein the castle key is configured to be detached from the first end (104-1) when the first rotating member (102) is at the second position only.

5. The fail-safe mechanism as claimed in claim 4, wherein the fail-safe mechanism comprises:
a second rotating cam arrangement operatively configured with the second gas-insulated switchgear, and the second rotating cam arrangement comprises:
a second rotating member (108), having a fifth end (108-1) and a sixth end (108-2) with a second tapered profile, configured to be rotated, after detaching the castle key, between a third position and a fourth position, wherein the second rotating member (108) is configured to rotate, from the fifth end, between the third position and the fourth position using the castle key; and
a second member (110), having a seventh end (110-1) and an eight end (110-2), slidably configured with a second rotational plate (108) of the second gas-insulated switchgear (300), wherein on rotating the second rotating member (108) to the fourth position, the second member is (110) pushed, from the seventh end (110-1), by the second tapered profile facilitating sliding the eighth end (110-2) out of a second slot (302-1) of the second rotating plate (300).

6. The fail-safe mechanism as claimed in claim 5, wherein the second gas-insulated switchgear comprises a second disconnector configured with electrical earth.

7. The fail-safe mechanism as claimed in claim 5, wherein sliding the eighth end (110-2) out of a second slot (302-1) of the second rotating plate (302) facilitates rotation of the second rotational plate (108) till a pre-defined degrees such that the second disconnector is electrically coupled with the electrical earth to earth the connecting cable.

8. The fail-safe mechanism as claimed in claim 5, wherein the eighth end (110-2) is slid into the second slot (302-1) when the second rotating member (108) is at the third position such that the second rotational plate (302) is prevented from rotating till the pre-defined angle such that the second disconnector is electrically decoupled from the electrical earth.