CA2678541A1

CA2678541A1 - Apparatus and method for remotely blocking an open end of a conductor of an energized electrical transmission system

Info

Publication number: CA2678541A1
Application number: CA 2678541
Authority: CA
Inventors: Leo Morin
Original assignee: Cantega Technologies Inc
Current assignee: Cantega Technologies Inc
Priority date: 2009-09-14
Filing date: 2009-09-14
Publication date: 2011-03-14

Abstract

An apparatus and method for remotely blocking an open end of a conductor of an energized electrical transmission system. A cover has a cover end for blocking the open end of the conductor. The cover has an external eyebolt. A dielectric hotstick has a hook at a remote end of the dielectric hotstick. The hook may be removably connected to the external eyebolt for remote installation of the cover end blocking the open end of the conductor. The cover end may be remotely installed blocking the open end of the conductor using a dielectric hotstick operated by a user who is in a position outside a safe Limit of Approach. The cover end may comprise a compressible material such as rubber or memory foam.

Description

APPARATUS AND METHOD FOR REMOTELY BLOCKING AN OPEN END OF A
CONDUCTOR OF AN ENERGIZED ELECTRICAL TRANSMISSION SYSTEM
TECHNICAL FIELD
[0001] This application relates to apparatuses and methods for remotely blocking an open end of a conductor of an energized electrical transmission system.

BACKGROUND

[0002] Conductors of electrical transmission systems may have open ends that afford attractive nesting or storage cavities for various animals. An example conductor of this type may be part of a pipe bus.

SUMMARY

[0003] An apparatus is disclosed for remotely blocking an open end of a conductor of an energized electrical transmission system, the apparatus comprising: a cover having a cover end for blocking the open end of the conductor, the cover having an external eyebolt;
and a dielectric hotstick with a hook at a remote end of the dielectric hotstick, the hook being configured to engage the external eyebolt for remote installation of the cover end blocking the open end of the conductor.

[0004] A method is also disclosed of remotely blocking an open end of a conductor of an energized electrical transmission system, the method comprising:
remotely installing a cover end of a cover blocking the open end of the conductor using a dielectric hotstick operated by a user who is in a position outside a safe Limit of Approach.

[0005] An apparatus is also disclosed for remotely blocking an open end of a conductor of an energized electrical transmission system, the apparatus comprising: a cover having a cover end for blocking the open end of the conductor, the cover end comprising a laterally expandable plug such as rubber or memory foam.

[0006] These and other aspects of the device and method are set out in the claims, which are incorporated here by reference.

BRIEF DESCRIPTION OF THE FIGURES

[0007] Embodiments will now be described with reference to the figures, in which like reference characters denote like elements, by way of example, and in which:

[0008] Fig. 1 is an exploded perspective view of a cover for blocking the open end of a conductor.

[0009] Fig. IA is a perspective view of the cover of Fig. 1 installed blocking the previously open end of the conductor.

[0010] Fig. 2 is a perspective view of a user installing the cover of Fig. 1 over the open end of a conductor.

[0011] Fig. 3 is a close-up perspective view of the cover of Fig. lbeing remotely installed onto the open end of the conductor.

[0012] Fig. 4 is a close-up perspective view of a hook control element for gripping and releasing the cover of Fig. 3.

DETAILED DESCRIPTION

[0013] Immaterial modifications may be made to the embodiments described here without departing from what is covered by the claims.

[0014] Electric poles, towers, and other electrical equipment including substations may have various open conductor cavities that provide attractive roosts for birds, particularly in treeless regions. If the wings of a bird simultaneously contact a conductor and another object such as an adjacent conductor, support tower or tree, the resulting electrical short-circuit can kill the bird and also damage the power system. The electrical short can further cause electrical system damage resulting in power outages. Further, the nesting of birds in open cavities in electrical systems increases the risk that predators will be attracted to the nests and cause a power fault or outage. Predators can be mammals such as raccoons or cats, birds such as magpies, or snakes.

[0015] Substations transform power from transmission voltages to distribution voltages, typically ranging from 2400 volts to 37,500 volts. Distribution voltages allow for reduced system clearances. These reduced clearances between phase to ground and phase to phase, increase station susceptibility to bird or animal caused outages.
Faults caused by birds and other animals often trigger sensitive relay protection schemes, resulting in substation lockouts, interrupting service to thousands or possibly tens of thousands of customers and at the same time damaging expensive substation equipment.

[0016] Thus, in the field of electrical power transmission and distribution there is a need to protect open conductors in electrical power systems from intrusion or occupation by birds and other animals. The variety and number of proposed solutions for repelling birds and other animals from electrocution risks highlights the persistence and magnitude of the problems created by such undesirable intrusion.

[0017] The inventor's own prior patent document discloses protectors for components of electrical power transmission systems, see United States patent publication no.
20080123254, as well as methods of making such protectors. However, in order to install such protectors, a power-down of the electrical system may be required, which adds to the cost of protecting the electrical equipment.

[0018] Power downs for the purpose of measuring electrical equipment for protective covers can keep a system down for a half a day or longer time period, at great cost. Some systems are operated under the direction of a regulatory and scheduling authority that controls the system's downtime scheduling. In locations with minimal spare power transmission capacity, it can be a challenge for a system to get the downtime needed to access its equipment. Because electrical systems are usually scheduled for maintenance downtime on a fairly short notice (typically a week for non-emergency situations), and because scheduled downtime may be cancelled by the Regulatory Authority on an extremely short notice, there is no guarantee that personnel will be available to install the required component during a system's available downtime period. As a result, a system can experience significant delays in protecting their equipment.

[0019] Thus, there is a need for installing conductor end covers on energized equipment by a person positioned outside the Limits of Approach.

[0020] Referring to Fig. 2, an apparatus 10 for remotely blocking an open end 12 of a conductor 14 of an energized electrical transmission system 16 is disclosed.
Referring to Fig.
3, apparatus 10 may comprise a cover 18, such as a plug, and a dielectric hotstick 20. Cover 18 may have a cover end 22 for blocking the open end 12 of the conductor 14.
The cover end 22 may insert into the open end 12 as shown, or slip at least partially over and around the external circumferential surface area 25 of the conductor 14, or both. Open end 12 of conductor 14 is illustrated as having a circular cross-section, although this is not required and other cross-section shapes are possible such as polygon shapes. Cover 18 may have an external eyebolt 24, which may extend from an external end 26 opposite the cover end 22.
Eyebolt 24 may extend along an insertion axis 28 of the cover as shown, or eyebolt 24 may be at a suitable angle to axis 28. Referring to Fig. 1, external eyebolt 24 may comprise an eyelet 30 and a zbolt 32. Bolt 32 may be positioned through aligned bores in the other components of the cover 18 as shown, securing the components together with a nut 34 at the cover end 22. Referring to Fig. lA, the eyebolt 24 may extend from the external end 26.
External end 26 may be adapted to be outset from the open end 12, for example if the external end 26 is flat across the open end 12 as shown, when installed blocking the open end 12. Outset in this context is understood to be the opposite of inset, in order to exclude the provision of a cavity in external end 26 of cover 18 of which animals would be able to occupy.

[0021] Between nut 34 and eyelet 30 may be various components, for example external and internal washers 36 and 38, respectively, and plug material 40.
The nut 34 and eyebolt 24 together form an exemplary means for compressing the plug material longitudinally and thus providing lateral expansion of the plug material 40.
External washer 36 may act as a lid or cap. At least part of cover 18 may be magnetic, in order to magnetically secure to conductor 14. Plug material 40 may have a cross-section that is slightly larger than the bore of the conductor 14 and may be compressible, with varying degree of elasticity, to fit within the conductor 14 under compression. This ensures a tight fit within open end 12. Plug material 40 may comprise, for example memory foam, rubber or other compressible material. Suitable memory foam may have a range of density of 3-6 pounds per cubic foot. Memory foam may be advantageous because it is easily compressed and returns slowly to its original shape in order to fill and seal the open end 12 of the conductor 14. Thus, the memory foam may be compressed by an operator, by for example turning one or both of the nut 34 and eyelet 30 in relation to each other, and the cover 18 installed before full expansion has taken place. Memory foam is also adept at forming a suitable seal, which does not have to be a fluid-tight seal. In other embodiments, rubber may be used, for example with a density range from 0.945 - 1.2 grams per cubic centimeter.
Suitable rubber may have a Poisson's ratio of 0.5, although materials exhibiting other values of Poisson's ratio may produce acceptable results. Other suitable materials may be used, such as polymers and elastomers. Suitable materials may have acceptable transverse profile deformation and maintain such deformation over time, when compressed longitudinally.
Suitable materials such as rubber may also have a durometer range from 60 A to 90 A. For all ranges provided herein, materials with values outside the ranges are possible.

[0022] Although material 40 has been described with relation to the embodiment of cover end 22 being a plug, it should be understood that material 40 may also be used in other arrangements, for example if material 40 is arranged to surround the external circumferential surface area 25 of conductor 14. In this example, the material 40 would have a bore for receiving conductor and the bore would be dimensioned to be slightly larger than the outer diameter of the conductor 14 so that the material 40 would fit with a compressed fit on the outside of the conductor 14.

[0023] Referring to Fig. 2, dielectric hotstick 20 may have a hook 42 at a remote end 44 of the dielectric hotstick 20. Referring to Fig. 3, in use, the hook 42 engages the external eyebolt 24 for remote installation of the cover end 22 blocking the open end 12 of the conductor 14. The cover 18 is configured so that the external eyebolt 24 extends externally when the cover 18 is installed on the conductor. Referring to Figs. 3 and 4, the dielectric hotstick 20 comprises a hook control element 46, for example a hand grip as shown, at an end 48 of the dielectric hotstick 20 opposed to the remote end 44. The hook control element 46 may be connected to open and close the hook 42 to grip and release, respectively, the eyebolt 24. Control element 46 may operate a dielectric control rod 47 that opens and closes the hook 42. Hotstick 20 may be used to grip the cover 18, place the cover end 18 blocking the open end 12, and then release the cover 18 in place. In some embodiments, the hotstick, for example a shotgun hotstick, may be telescopic. The construction of hot stick stock 20 should meet regulatory requirements and may have a length sufficient to provide limit of approach protection for high voltage power equipment energized at more than 750 V. The use of hook 42 and eyebolt 24 allows the insertion axis 28 of the cover 18 to be angled relative to the hotstick 20 shaft, in order to allow cover 18 to be easily installed in elevated conductors from the ground level, or from other generally awkward positions.

[0024] Referring to Fig. 2, an exemplary method of remotely blocking an open end 12 of a conductor 14, for example a sliding pipe bus, of an energized electrical transmission system 16 is illustrated. Cover end 22 is remotely installed blocking the open end 12 of the conductor 14 using dielectric hotstick 20 operated by a user 50 who is in a position outside a safe Limit of Approach, for example limit of approach 52D. Remotely installing may be carried out with hook 42 removably connected to the external eyebolt 24.
Standard limits of approach are generally set by the IEEE for live electrical systems. It should be understood that the limits of approach may vary according to region. The limits of approach 52 around energized equipment generally widens as the voltage increases. In the illustration of Fig. 2, the limits of approach 52 correspond to increasing voltages, and thus increasing radii, from limits of approach 52A-52D. For this purpose, hotstick 20 may be provided in a length that is suitable for the various limits of approach standards in all jurisdictions. In some embodiments, the conductor 14 comprises non-energized, for example grounded, electrical equipment that is located in close proximity to energized equipment of the energized electrical transmission system, and thus the conductor 14 lies within the Limit of Approach of the adjacent energized equipment.

[0025] The dielectric material which constitutes at least a part of the hot stick 20 may comprise a single part material or multiple part material mixed before application, and may be formulated from a combination of liquid and semi-solid or solid components.
Electrical transmission system may refer to any apparatus intended to transmit power. It will be understood that the teachings equally apply and may be adapted to any commercially used voltage range or any suitable transmission system. In another embodiment the hot stick dielectric control rod 47 may be replaced with a different driving system, such as a pulley system. The driving system may be internal or external to the hotstick 20. Hot stick 20 may be separated into more than one part, for ease of transport. For example, hot stick 10 may collapse into three parts. For further example, hot stick 10 may be provided as a multi-part kit.

[0026] In the claims, the word "comprising" is used in its inclusive sense and does not exclude other elements being present. The indefinite article "a" before a claim feature does not exclude more than one of the feature being present. Each one of the individual features described here may be used in one or more embodiments and is not, by virtue only of being described here, to be construed as essential to all embodiments as defined by the claims.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An apparatus for remotely blocking an open end of a conductor of an energized electrical transmission system, the apparatus comprising:
a cover having a cover end for blocking the open end of the conductor, the cover having an external eyebolt; and a dielectric hotstick with a hook at a remote end of the dielectric hotstick, the hook being configured to engage the external eyebolt for remote installation of the cover end blocking the open end of the conductor.

2. The apparatus of claim 1 in which the dielectric hotstick comprises a hook control element at an end of the dielectric hotstick opposed to the remote end, the hook control element being connected to open and close the hook to grip and release, respectively, the eyebolt.

3. The apparatus of any one of claim 1 - 2 in which the eyebolt extends from an external end of the cover opposed to the cover end, the external end adapted to be outset from the open end of the conductor when installed blocking the open end.

4. The apparatus of claim 3 in which the external end is flat.

5. The apparatus of any one of claim 1 - 4 in which the cover comprises a plug.

6. The apparatus of any one of claim 1 - 5 in which the cover end comprises memory foam.

7. The apparatus of any one of claim 1 - 6 in which the cover end comprises rubber.

8. The apparatus of any one of claims 1-7 in which the cover comprises material that is laterally expandable under longitudinal compression to engage an inside surface of a conductor, and means for providing longitudinal compression on the material.

9. A method of remotely blocking an open end of a conductor of an energized electrical transmission system, the method comprising:
remotely installing a cover end of a cover blocking the open end of the conductor using a dielectric hotstick operated by a user who is in a position outside a safe Limit of Approach.

10. The method of claim 9, in which the cover comprises a plug.

11. The method of any one of claim 9 - 10 in which:
the cover further comprises an external eyebolt;
the dielectric hotstick further comprises a hook at a remote end of the dielectric hotstick; and remotely installing is carried out with the hook removably connected to the external eyebolt.

12. The method of any one of claim 9 - 11 in which the conductor comprises a bus.

13. An apparatus for remotely blocking an open end of a conductor of an energized electrical transmission system, the apparatus comprising:
a cover having a cover end for blocking the open end of the conductor, the cover end comprising material that is laterally expandable under longitudinal compression to engage an inside surface of a conductor, and means for providing longitudinal compression on the material.

14. The apparatus of claim 13 in which the material comprises memory foam.