WO2011089544A2

WO2011089544A2 - A connector component for use in power transmission systems

Info

Publication number: WO2011089544A2
Application number: PCT/IB2011/050194
Authority: WO
Inventors: Brian Katz
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-01-20
Filing date: 2011-01-17
Publication date: 2011-07-28
Anticipated expiration: 2012-07-20
Also published as: WO2011089544A3

Abstract

The invention relates to a connector component (10, 32, 50), indicator component (34, 40), support installation (130), and a method of indicating failure of a connector component for an electricity transmission line. The connector component (10) includes a body (12) which is connected or connectable to a conductor and a thermochromic material (14) which is proximate the body (12) and which undergoes a non-reversible colour change in response to a rise in temperature of the body (12) past a threshold temperature thereby to provide a visual indication of a failure condition of which heat is a symptom (e.g. flashover).

Description

TITLE: A connector component for use in power transmission systems.

FIELD OF INVENTION

This invention relates generally to power (and telegraph) transmission systems and specifically to a connector component for use in such transmission systems, and to a connector component assembly.

BACKGROUND OF INVENTION

The Inventor is aware of conventional power transmission systems which include a plurality of pylons or utility poles (generally referred to as supports or structures) between which electrical cables (i.e. conductors) are suspended.

The conductors are attached to the respective supports by means of insulators which ensure insulation of electric current between the conductor and the supports. The insulators can be made of glass, ceramic or composite material.

Insulator pollution is an important factor in quality and reliability for power transmission. Insulators are exposed to air pollution, dust, salt, water and other contaminants, which become fixed to insulating surfaces causing surface resistivity of the insulators to reduce which, in turn, can cause conduction along the surface of the insulator. This conduction may lead to flashover or arcing, which in turn results in breakdown of insulation and partial or total damage to the insulator.

Electrical current flowing across insulator surfaces causes a temperature rise. When the insulator has been damaged by total flashover, it is difficult visually to locate or observe the damaged insulator. Inspection is usually done on foot or by helicopter, making nearby examination of insulators impractical.

Other connector components, such as a conductive joint, may also be liable to failure. For instance, if the interface between the conductors and the joint is faulty, conduction will be less than ideal, leading possibly to increased operating temperature and ultimately to failure of the joint. Again, visual detection can be difficult. The Inventor desires a connector component which overcomes or at least alleviates these drawbacks.

SUMMARY OF INVENTION According to a first aspect of the invention, there is provided a connector component which includes:

a body which is connected or connectable to a conductor; and a thermochromic material which is proximate the body and which undergoes a non-reversible colour change in response to a rise in temperature of the body past a threshold temperature thereby to provide a visual indication of a failure condition of which heat is a symptom.

The body may be integral with the thermochromic material. In fact, the body may be made of the thermochromic material. Instead, the thermochromic material may be embedded in the body or the body impregnated with the thermochromic material. Alternatively, the thermochromic material may be applied, e.g. painted, to a surface of the body. In one embodiment of the invention, the connector component may be an insulator. In such case, one end of the body may be connected or connectable to at least one end or part of a conductor (e.g. transmission wire), the other end being connected or connectable to a support (e.g. a utility pole). In the context of this specification, the term "insulator" means any insulating material or material restricting current flow used to isolate a current carrying conductor from a utility support. The insulator may be a unitary insulator known as "rigid insulators" or may be "suspension insulators" comprising a number of different elements possibly made of glass, ceramic or composite material.

The failure condition may be flashover and the threshold temperature at which the thermochromic material undergoes the non-reversible colour change may be below a temperature associated with flashover but above normal operating conditions.

In another embodiment, the connector component may be a conductive joint. In such case, the body may be tubular or cylindrical and connected or connectable, sleeve-fashion, to ends of two separate conductors, thereby to link the conductors electrically.

The failure condition may be joint failure and the threshold temperature at which the thermochromic material undergoes the non-reversible colour change may be below a temperature associated with joint failure but above normal operating temperature.

The thermochromic material may include for example, ink, paint, particles, or any substance sensitive to a temperature change.

According to a second aspect of the invention, there is provided an indicator component which includes:

a thermochromic indicator operable to undergo a non-reversible colour change in response to a rise in temperature of the connector component past a threshold temperature thereby to provide a visual indication of a failure condition of which heat is a symptom; and

an attachment formation coupled to the thermochromic indicator, being operable to attach the indicator component to or proximate to a connector component. The indicator may be in the form of a tag in which the attachment formation is a mechanical attachment formation, e.g. a clamp or hook, for mechanical attachment to the connector component. Instead, the indicator may be in the form of a tag in which the attachment formation is an adhesive attachment formation for adhering the tag to the connector components (e.g. insulators or joints).

In another embodiment there is provided a connector component assembly which includes:

a connector component; and

an indicator component.

According to another aspect of the invention, there is provided a support installation which includes:

a support;

a mounting formation operable to mount a connector component to the support; and

a thermochromic indicator connected or connectable to the support proximate the mounting formation, the indicator being operable to undergo a non-reversible colour change in response to a rise in temperature of the support past a threshold temperature thereby to provide a visual indication of a failure condition of which heat is a symptom.

The support installation may include a connector component connected to the mounting formation.

The invention extends to a method of indicating failure of a connector component, the method including:

applying a thermochromic material to the connector component such that when a temperature of the connector component rises above a temperature threshold, the thermochromic material changes colour irreversibly thereby to provide a visual indication of a failure condition of which heat is a symptom.

The invention also extends to a method of indicating failure of a connector component connected to a support, the method including:

applying a thermochromic material to the support proximate the connector component such that when a temperature of the support rises above a temperature threshold, the thermochromic material changes colour irreversibly thereby to provide a visual indication of a failure condition of which heat is a symptom.

The invention also extends to a method of indicating failure of a connector component, the method including visually inspecting the thermochromic material to ascertain whether a colour change has occurred thereby to determine whether or not the failure condition has occurred.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be further described, by way of example, with reference to the accompanying diagrammatic drawings.

In the drawings:

Figure 1 shows a schematic view of a conventional power transmission system;

Figure 2 shows a schematic view of one embodiment of a connector component in the form of an insulator, in accordance with the invention;

Figure 3 shows a schematic view of another embodiment of a connector component in the form of an insulator, in accordance with the invention;

Figure 4 shows a schematic view of another embodiment of a connector component in the form of an insulator, in accordance with the invention;

Figure 5 shows a schematic view of one embodiment of a connector component assembly, in accordance with the invention; Figure 6 shows a schematic view of another embodiment of a connector component assembly, in accordance with the invention;

Figure 7 shows a cross-sectional view of a connector component assembly, in accordance with the invention; and

Figure 8 shows a schematic view of a support installation in accordance with the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

In Figure 1 of the drawings, reference numeral 100 refers to a conventional power transmission system. The power transmission system includes a plurality of supports to which conductors are suspended by means of connector components linked to the supports. The connector components may be insulators and, in conventional fashion, may be susceptible to flashover failure.

In Figure 2 of the drawings, reference numeral 10 generally indicates a connector component in accordance with one embodiment of the invention. The connector component 10 is in the form of an insulator. The insulator 10 has a body 12 which includes a plurality of discs (or sheds), customarily made of glass, ceramic or composite material, and, in accordance with the invention, made at least partially of a thermochromic material 14. The number of discs in the body 12 depends generally on the voltage carried by the conductor e.g. transmission wire. The higher the voltage in the transmission wire, the greater the number of discs required.

In conventional fashion, the insulator 10 further includes a first connection element 16 at one end which is linked to and/or carries the conductor and a second connection element 18 at the other end which is used for attachment to the support (e.g. a pylon). The connection elements 16, 18 are secured to the body 12 with cement to ensure mechanical linkage between the connection elements 16, 18 and the insulator 12. In Figure 3 of the drawings, another embodiment in the form of an indicator component, and more specifically in the form of an insulator 10.1 , is illustrated. The body 12 of the insulator 10 is embedded or impregnated with thermochromic material 14.

In another embodiment of the invention, shown in Figure 4, the indicator component 10 is in the form of an insulator 10.2 which includes a thermochromic material 14 which is applied (e.g. painted/printed) to the surface of the body 12. The thermochromic material 14 may be ink, paint, particles, or any material which is capable of application to an external surface of the body 12.

In Figure 5 of the drawings, reference numeral 30 refers to a connector component assembly which includes a connector component 32 in the form of an insulator and a thermochromic indicator component 34 connected or connectable to the insulator 32. The thermochromic indicator component 34 is in the form of a tag 36 having a mechanical attachment formation (e.g. a hook or a clamp) 38 which may be attached to the insulator 32 or to the support proximate the insulator 32. The tag 36 is coated with or made of a thermochromic material sensitive to a temperature change.

Figure 6 shows, in another embodiment of the invention, a thermochromic indicator component 40 in the form of a tag or sticker. The indicator 40 includes an adhesive attachment formation on one surface to adhere to the insulator 32 and the other surface includes a thermochromic material.

The indicator 34, 40 has dimensions that enable it to be readily seen from a distance, specifically from the ground (e.g. when an observer is on foot) or from the air (when the observer is in a helicopter).

In Figure 7 of the drawings, reference numeral 50 indicates to a connector component assembly 50, in accordance with another embodiment of the invention, including a conductive joint 52 which has a cylindrical or tubular body. The body defines a channel therein to accommodate respective ends of two separate conductors, sleeve-fashion, thereby to link the conductors electrically. The conductive joint 52 has a thermochromic indicator 54 in a form of a tag which includes a thermochromic material.

With reference to Figure 8, reference numeral 130 refers generally to a support installation in accordance with a further embodiment of the invention. A connector component in the form of an insulator 32 is connected to a support structure in the form of an electricity pylon indicated by reference numeral 33. A connection element 18 of the insulator 32 is hooked or secured to a mounting formation (not illustrated) of the pylon 33. A thermochromic material 14 is applied (e.g. painted/adhered or otherwise attached) to a surface of the pylon 33. It is to be understood that, alternatively or in addition to the material 14, a thermochromic indicator 40 or tag 36 as shown in Figures 5 and 6 may also be attached to the electricity pylon 33.

The thermochromic material 14 integral with the body 12 or forming part of the indicator 34, 40, 54 undergoes a non-reversible colour change when the temperature rises to a level associated with a flashover thereby to provide a visual indication of a failure condition of which heat is a symptom.

In manufacture or installation, new connector components such as insulators 10, joints 52 or portions of an electricity pylon 33 can be manufactured with the thermochromic material 14 integral therewith. Similarly, existing connector components, such as insulators 32 or joints 52 and parts of the electricity pylon 33, can be retrofitted with thermochromic material, for example in the form of indicator 34, 40, 54, thereby to form a connector component assembly 30, 50. In use, and referring now to the insulator 10 for simplicity of explanation, the thermochromic material 14 of an insulator 10 which has not undergone any flashover failure will have a default colour, such as yellow. Thus, any insulator 10 displaying yellow thermochromic material 14 can be observed visually to be free of any past flashover failures, and thus operating within acceptable parameters.

Conversely, if flashover has occurred in the insulator 10, this would have caused the insulator 10 briefly to heat up to a temperature higher than the colour change threshold of the thermochromic material 14. Thus, upon flashover occurring, the thermochromic material 14 non-reversibly changes colour to, for example, black. Therefore, even once the flashover has abated and the insulator 10 reverts to its normal function, there is visual, observable evidence that that specific insulator 10 had previously failed.

If flashover occurs, the electrical distribution system may short-circuit and may trip. This indicates to an operator that one of the components along the conduction line has failed and may intermittently fail in the future. Thus, the operator can initiate an inspection, either by means of an observer walking along the ground beneath powerlines and looking up at the thermochromic material 14 of successive insulators 10, or by means of an observer looking down from a helicopter, to identify an insulator 10 which is not yellow or which no longer includes a yellow indicator 34, 40, 54. Upon identification of the failed insulator 10, repair/replacement thereof can be initiated.

Similarly, a joint 50 which is not making a good connection between its respective electrical conductors tends to offer more impedance than it should and accordingly heats up. Identifying such a faulty joint 50 can be difficult because it is still conducting electricity, but just not as efficiently as it should be. Thus, visual observation of a joint 50 with a black tag 54, as opposed to a yellow one, indicates that that joint 50 should be repaired or replaced.

When a flashover occurs across a connector component such as an insulator 32, a portion of the electricity pylon 33 to which the insulator 32 is connected experiences a rise in temperature. Therefore, portions of the electricity pylon 33 proximate the insulator 32 are covered with the thermochromic material 14 such that, in the event of a flashover occurring, the rise in temperature in the electricity pylon 33 causes the thermochromic material 14 to undergo a non-reversible colour change which can be easily spotted by an observer. It therefore serves as an indication that a flashover has occurred.

The Inventor believes that the connector component 10, 32, 50 in accordance with the invention is advantageous in that it makes the inspection of such connector components much easier. The Inventor believes further that this connector component 10, 50 can be produced cost effectively, or that such a thermochromic material can be retrofitted to existing connector components 32.

Claims

1 . A connector component for an electricity transmission line, the connector component including:

2. A connector component as claimed in claim 1 , in which the body includes the thermochromic material therein.

3. A connector component as claimed in claim 1 , in which the thermochromic material is applied to a surface of the body.

4. A connector component as claimed in any of claims 1 to 3 inclusive, in which the connector component is an insulator, wherein one end of the body is connected or connectable to a conductor, the other end being connected or connectable to a support.

5. A connector component as claimed in any of claims 1 to 4 inclusive, in which the failure condition is flashover and in which the threshold temperature at which the thermochromic material undergoes the non-reversible colour change is below a temperature associated with flashover but above normal operating temperature.

6. A connector component as claimed in any of claims 1 to 3 inclusive, in which the connector component is a conductive joint, wherein the body is connected or connectable, sleeve-fashion, to ends of two separate conductors, thereby to link the conductors electrically.

7. A connector component as claimed in claim 6, in which the failure condition is joint failure and in which the threshold temperature at which the thermochromic material undergoes the non-reversible colour change is below a temperature associated with joint failure but above normal operating temperature.

8. An indicator component including:

an attachment formation coupled to the thermochromic indicator, being operable to attach the indicator component to or proximate to a connector component.

9. An indicator component as claimed in claim 8, which is in the form of a tag in which the attachment formation is a mechanical attachment formation for mechanical attachment to the connector component.

10. An indicator component as claimed in claim 8, which is in the form of a tag in which the attachment formation is an adhesive attachment formation for adhering to the connector component.

1 1 . A connector component assembly which includes:

a connector component; and

indicator component as claimed in any of claims 8 to 10 inclusive.

12. A support installation which includes;

a support;

13. A support installation as claimed in claim 12, which includes a connector component connected to the mounting formation.

14. A method of indicating failure of a connector component, the method including:

15. A method of indicating a failure of a connector component connected to a support, the method including:

16. A method as claimed in claim 14 or claim 15, which includes visually inspecting the thermochromic material to ascertain whether a colour change has occurred thereby to determine whether or not the failure condition has occurred.