Description: A SYSTEM PROVIDING HERMETICALLY SEALED FIBER ROUTING ARRANGEMENT OF HIGH VOLTAGE OPTICAL CURRENT TRANSFORMER
FIELD OF THE INVENTION:
[001] The present invention relates to a system providing hermetically sealed fiber routing arrangement of high voltage optical current transformer (OCT). More particularly, the invention relates to the development and implementation of hermetic package for providing a hermetic environment internal to the hollow insulator and for providing optical fiber channelizing through Low Voltage (LV) flange and push fit adapter design for ease of fiber handling during assembly and maintenance.

BACKGROUND/PRIOR ART OF THE INVENTION:
[002] 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.
[003] Optical Current Transformers (OCT) are non-conventional current transformers which use polarized light to deduce the precise magnitude of current flowing in primary conductor in high voltage substations. As the OCTs are made up of optical components & fiber, designing them for high voltage installations is challenging, as the optical components and fiber used are very delicate and fragile. OCT requires special/novel design of hermetic package to provide a hermetic environment internal to the hollow insulator and for providing optical fiber channelizing through LV flange arrangement designed by the manufacturer. Broadly, various components of the hermetic package a) LV flange compatible with adapter, b) Grooves for adapter to flange sealing, c) Adapter to accommodate fiber routing, and d) Resin hardener composition compatible to fiber cable for through-adapter sealing.
[004] Various innovations and patents cover the different sealing techniques and technologies developed for optical fiber hermetical sealing.
[005] In a prior art, US9329336B2, titled “Method of forming a hermetically sealed fiber to chip connection” a method of providing a hermetically sealed optical connection between an optical fiber and an optical element of a chip and a photonic-integrated chip manufactured using such method is disclosed.
[006] Another prior art, US4413881A, titled “Optical fiber hermetic seal” describes a hermetic seal for an optical fiber is fabricated by casting or molding a mass of fusible alloy around the fiber so that the alloy solidifies within a confined space.
[007] Another prior art, US20020005574A1, titled “Methods and apparatus for hermetically sealing electronic packages” describes an electronic package and/or package lid includes at least one connection slot for receiving a line, such as an optical fiber. The package and/or package lid also includes at least one sealant slot proximate the connection slot. Optical fibers are connected to a component, such as an opto-electronic component, through the connection slot. A sealant provided via the sealant slot hermetically seals the optical fibers within the connection slot.
[008] Also various patents cover the manufacturing of a fiber embedded in insulator for different applications.
[009] A prior art, US5127083A, titled “Optical fiber built-in type composite insulator and method of producing the same” describes the invention of optical fiber built-in type composite insulator and a method of producing the same. This patent relates to the optical fiber embedded insulator which are mainly used in detection systems for finding fault points at electric power transmission lines and substation.
[0010] Another prior art, US5594827A, titled “Electrical insulator equipped with optical fibers, and manufacturing method therefor” describes an electrical insulator equipped with optical fibers inside and is used to serve as insulating support member for an outdoor high voltage installation.
[0011] Another prior art, US6547448B2, titled “Embeddable fiber optic connector and associated method” describes an invention of embeddable fiber optic connector and associated method. The application covered under the patent are fiber optic sensors used to measure structural conditions in structural parts viz. strain, temperature, pressure, acceleration etc.
[0012] Another prior art, US20020175001A1, titled “Composite electrical insulator including an integrated optical fiber sensor” describes the development of composite electrical insulator including an electrical optical fiber sensor. The integrated sensor measures the stresses of mechanical and thermal origin acting on the insulator while it is in operation. It is constituted by an optical fiber having a Bragg grating implanted on it.
[0013] Optical fibers play an important role in communication/data-transfer and other related applications. Optical Current Transformers (OCT) are important components of a digital substation for metering of power, protection and control applications. Optical fibers in OCT provides path for the launched light, senses the primary current in the lines and sends the modified light signal back to the optoelectronics unit for accurate measurement of the primary current in the power transmission lines. Optical CT has been designed with composite hollow type insulator, which is used to channelize the optical fiber. To protect moisture ingress inside the insulator a sealing design was incorporated. Therefore, there is a need of ease of fiber handling during assembly and maintenance.
[0014] In view of the above, there is requirement to devise an apparatus/fixture which can address the aforesaid shortcoming(s)/fulfill the requirements. Hence, the present invention has been introduced to serve the purpose efficiently.
[0015] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

OBJECTS OF THE INVENTION:
[0016] It is therefore the object of the present subject matter to provide a hermetic environment internal to the hollow insulator which overcomes the aforementioned and other drawbacks in prior method/product/apparatus.
[0017] An object of the present invention is developing an adapter to accommodate optical fiber routing and tightening arrangement on a LV flange.
[0018] Another object of the present invention is to develop a low voltage (LV) side flange which consists of grooves for O-rings for adapter to flange sealing.
[0019] Another object of the present invention is to provide an optical fibre channelizing through LV flange.
[0020] Another object of the present invention is to finalizing resin hardener for in-adapter filling compatible with optical fiber for ensuring hermetical sealing through adapter.
[0021] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION:
[0022] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.
[0023] The present invention relates to a system providing hermetically sealed fiber routing arrangement of high voltage optical current transformer (OCT).
[0024] The present invention discloses development and implementation of hermetic package for providing a hermetic environment internal to the hollow insulator and for providing optical fiber channelizing through LV flange and push fit adapter design for ease of fiber handling during assembly and maintenance.
[0025] According to the present invention, there is disclosed a system providing Hermetically Sealed Fiber routing arrangement of High Voltage (HV) Optical Current Transformer (OCT), the system comprising:
a push fit adaptor, having a head and a barrel design; and
a Low Voltage (LV) side flange, having an adapter mating port for connecting with the push fit adaptor;
wherein the head incorporates screw holes for tightening of the push fit adaptor, with LV flange and the central barrel hole for fiber routing and potting resin hardener for sealing purpose; and
the adapter mating port comprising a plurality of O-rings, a plurality of O-ring grooves, and a plurality of threaded holes.
[0026] In an aspect of the present invention, the Push Fit Adaptor which is made of light weight metallic material to guide the fiber out of the insulator from LV side of Optical Current Transformer (OCT).
[0027] In another aspect of the present invention, the one O-ring is provided for sealing of the head of the push fit adapter with the LV flange.
[0028] In another aspect of the present invention, the other two O-rings are placed in between the adapter mating port of the LV flange and push fit adapter barrel for ensuring sealing of barrel of push fit adapter and LV Flange for redundancy purposes and long life of sealing.
[0029] In another aspect of the present invention, the head is provided with the provision of disassembly holes placed 180° apart from each other.
[0030] In another aspect of the present invention, the barrel is made with tapered edge at the bottom for ensuring no harm to each of the plurality of the O-rings placed inside the groves of LV flange.
[0031] In another aspect of the present invention, a resin hardener is provided for routing and sealing of PM fiber through push fit adapter.
[0032] In another aspect of the present invention, the resin hardener is potted in the entire length of the barrel to ensure gas pressure handling capabilities, which is filled in the insulator for providing positive pressure inside insulator to deter any moisture ingress from the environment.
[0033] In another aspect of the present invention, the O-ring grooves are provided with tapered edges to make sure the safety of the O-rings during assembly of the push fit adapter in the adapter mating port.
[0034] The present invention is achieved by the features of principal claim and subsequent claims.
[0035] 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.

[0036] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[0037] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
[0038] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:

[0039] Figure 1 illustrates an isometric view of Hermetic Package for Low Voltage (LV) side fiber guiding cum sealing, in accordance with an embodiment of the present invention;

[0040] Figure 2 illustrates a front view and a back view of sealing of PM fiber through push fit adapter using resin hardener, in accordance with an embodiment of the present invention;

[0041] Figure 3 illustrates a top view of Low voltage (LV) flange with embedded grooves, flange to adapter sealing and tightening arrangement, in accordance with an embodiment of the present invention;

[0042] Figure 4 illustrates a back view of Low voltage (LV) flange showing placement of O-rings and fibre routing through adapter mating port, in accordance with an embodiment of the present invention;

[0043] Figure 5 illustrates a cross sectional view of push fit type adapter and flange assembly, in accordance with an embodiment of the present invention;

[0044] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily 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 OF PREFERRED EMBODIMENT(S) OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:

[0045] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[0046] The present invention relates to a system providing hermetically sealed fiber routing arrangement of high voltage optical current transformer (OCT).
[0047] In present invention development and implementation of hermetic package is disclosed for providing a hermetic environment internal to the hollow insulator and for providing optical fiber channelizing through LV flange, comprising push fit adapter design for ease of fiber handling during assembly and maintenance.
[0048] Optical fibers play an important role in communication/data-transfer and other related applications. Optical Current Transformers (OCT) are important components of a digital substation for metering of power, protection and control applications. As delicate optical fibers are used in optical CTs at high & low voltage side in extreme harsh substation environment, the high/low voltage design and optical fiber guiding cum sealing design is very critical for trouble free 24X7 operation of the optical CT in switchyard. This innovation caters to innovative fiber guiding-cum-sealing method in optical CT, this invention specifically relates to the implementation of hermetic package for providing a hermetic environment internal to the hollow insulator and for providing optical fiber channelizing through LV flange, comprising push fit adapter design for ease of fiber handling during assembly and maintenance.
[0049] Now, reference may be made to the accompanying figures.
[0050] Referring to Figure 1, illustrating a Hermetic Package for Low Voltage (LV) side fiber guiding cum sealing. The LV side hermetic sealing package comprising of a developed LV side flange (1), a push fit adapter (2) and components of hermetic sealing package. The LV flange (1) is made of light weight metallic material and is designed to seal the insulator at bottom LV side. The LV flange (1) consist of a specially designed adapter mating port (9) for the push fit adapter (2). The output fiber is routed and guided through the insulator and is taken out through the LV side hermetic sealing package. The construction of the LV flange (1), and push fit adapter (2) is such that they ensure optimum sealing of the delicate fiber inside the insulator. A plurality of O-rings (15) are placed inside the groves of LV flange (1). The push fit adapter (2) helps in hermetical sealing, fiber routing, easy handling and protecting the delicate fiber during assembly/maintenance work of Optical CT. The push fit adapter (2) consists of a head (3) and a barrel (6) design. The head (3) incorporates a plurality of screw holes (7) for tightening of the push fit adapter (2) with LV flange (1) and a central barrel hole (8) for fiber routing and potting resin hardener for sealing purpose. Further for easy disassembly and maintenance purposes the head (3) is provided with the provision of disassembly holes (4) placed 180° apart from each other. The barrel (6) is made with tapered edge (5) at the bottom for ensuring no harm to each of the plurality of the O-rings (15) placed inside the groves of LV flange (1). The push fit adapter (2) receives the fiber (10) to further guide through the push fit adapter (2). The sealing of the embedded delicate fiber (10) was carried out by hard epoxy resin potted rugged feed through push fit adapter (2) which routes the fiber (10) out of the HV insulator.

[0051] Referring to Figure 2, illustrating a front view and a back view of routing and sealing of PM fiber (10) through push fit adapter (2) using resin hardener (11). The sealing in the central barrel hole (8) of the push fit adapter (2) is done using fiber (10) compatible resin hardener (11). The resin hardener (11) is potted in the entire length of the barrel (6) to ensure gas pressure handling capabilities that is filled in the insulator for providing positive pressure inside insulator to deter any moisture ingress from the environment.
[0052] Referring to Figure 3, illustrating a top view of Low voltage (LV) flange (1) with embedded grooves, Low voltage (LV) flange (1) to push fit adaptor (2) sealing and tightening arrangement showing the adapter mating port (9). The adapter mating port (9) consists of the plurality of the O-ring grooves (12), tapered edge (13) and a plurality of threaded holes (14). The adapter mating port (9) is provided with three O-ring grooves (12) to hold each of the plurality of the O-rings (15) in place for ensuring sealing between push fit adapter (2) and LV flange (1). The O-ring grooves (12) are provided with tapered edges (13) to make sure the safety of the O-rings (15) while assembly of the push fit adapter (2) in the adapter mating port (9). The plurality of the threaded holes (14) are provided on the LV flange (1) to ensure proper tightening of the push fit adapter (2) with the LV flange (1).

[0053] Referring to Figure 4, illustrating a back view of Low voltage (LV) flange (1) showing placement of O-rings (15) and fibre (10) routing through adapter mating port (9). Three O-rings (15) are provided in the adapter mating port (9). One O-ring (15) is used for sealing of head (3) of the push fit adapter (2) with the LV flange (1). Other two O-rings (15) are placed in between the adapter mating Port (9) of the LV flange (1) and push fit adapter (2) barrel (6) for ensuring sealing of barrel (6) of push fit adapter (2) and LV Flange (1) for redundancy purposes and long life of sealing.

[0054] Referring to Figure 5, illustrating a cross sectional view of push fit adapter (2) and flange (1) assembly showing the fiber (10) guiding cum sealing arrangement of Optical CT at LV side.

[0055] The material above has been given as an example without restricting scope of the invention to the same. Thus, other materials readily apparent to a person skilled in the art are understood to be within scope of the invention.

[0056] The developed LV flange (1) is used for:
a) Sealing of optical CT insulator at LV side,
b) Provision of adapter mating port (9),
c) Provision of O-ring grooves (12),
d) Sealing cum tightening arrangement for push fit adapter (2), and installing the Gauge coupling port (16), and
e) insulator O-ring (17).

WORKING OF INVENTION

[0057] The working of the invention is described below:
[0058] The developed hermitically sealed system (100) is fitted to the LV side of the composite hollow insulator, which has pressurized nitrogen gas filled inside it. The developed system (100) prevents the nitrogen gas to leak from the insulator maintaining gas pressure inside and at the same time enables the fiber optic cable to route out from the insulator, so that it can be connected to the ground equipment for data and signal transfer. The developed sealing cum fiber routing system (100) is used for extreme harsh outdoor substation environment and prevents moisture leak inside the insulator during service.

ADVANTAGES OF THE INVENTION
1. The advantage of present invention is that it works well with high voltage installations.
2. Another advantage of present invention is that it improves optical fiber routing and tightening arrangement.
3. Further another advantage of present invention is that it provides ease of fiber handling during assembly and maintenance.

TEST RESULT
[0059] The developed system (100) has been tested to provide hermetic sealing of high voltage insulator for harsh outdoor application. The system (100) has been tested to withstand a pressure of upto 20 bar. The feed-through fiber optic cable provided data and signal transmission as per requirement. The system (100) was also successfully tested to withstand ambient temperature from -40°C to +85°C by placing it in hot and cold climatic chamber.

[0060] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0061] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0062] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogue to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.

[0063] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0064] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0065] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0066] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

, Claims: WE CLAIM
1. A system (100) providing Hermetically Sealed Fiber (10) Routing Arrangement of High Voltage (HV) Optical Current Transformer (OCT), the system comprising:
a push fit adaptor (2) comprising a head (3) mounted with a barrel (6); and
a Low Voltage (LV) side flange (1), having an adapter mating port (9) for connecting with the push fit adaptor (2);
wherein the head (3) is having screw holes (7) for tightening of the push fit adaptor (2) with LV flange (1); and
the adapter mating port (9) comprising a plurality of O-rings (15), a plurality of O-ring grooves (12), and a plurality of threaded holes (14).
2. The system as claimed in claim 1, wherein the Push Fit Adaptor (2) is made of metallic material to guide the fiber (10) out of the insulator from Low Voltage (LV) side of Optical Current Transformer (OCT).
3. The system as claimed in claim 1 or 2, wherein the push fit adaptor (2) is provided with central barrel hole (8) for fiber routing and potting resin hardener for sealing purpose
4. The system as claimed in claim 1 or 3, wherein the one O-ring (15) is provided for sealing of the head (3) of the push fit adapter (2) with the LV flange (1).
5. The system as claimed in claim 1 to 4, wherein the other two O-rings (15) are placed in between the adapter mating Port (9) of the LV flange (1) and push fit adapter (2) barrel (6) for ensuring sealing of barrel (6) of push fit adapter (2) and LV Flange (1) for redundancy purposes and long life of sealing.
6. The system as claimed in claim 1 to 5, wherein the head (3) is provided with disassembly holes (4) placed 180° apart from each other.
7. The system as claimed in claim 1 to 6, wherein the barrel (6) is provided with tapered edge (5) at the bottom for ensuring no harm to each of the plurality of the O-rings (15) placed inside the groves of LV flange (1).
8. The system as claimed in claim 1 to 6, wherein a resin hardener (11) is provided for routing and sealing of PM fiber (10) through push fit adapter (2).
9. The system as claimed in claim 1 to 7, wherein the resin hardener (11) is potted in the entire length of the barrel (6) to ensure gas pressure handling capabilities, which is filled in the insulator for providing positive pressure inside insulator to deter any moisture ingress from the environment.
10. The system as claimed in claim 1 to 8, wherein the O-ring grooves (12) are provided with tapered edges (13) to make sure the safety of the O-rings (15) during assembly of the push fit adapter (2) in the adapter mating port (9).
Dated this 22nd day of April 2022

SOMA RANI MISHRA
IN/PA-1159
OF L.S.DAVAR & CO.
APPLICANT’S AGENT.