IES87149B2

IES87149B2 - Electrical field detecting system

Info

Publication number: IES87149B2
Authority: IE

Abstract

An electrical field detecting system (1) comprising a pair electrical detectors (3a, 3b), said detectors being configured to be worn simultaneously on a user's arms or wrists, one detector on each said arm or wrist; and each detector being configured to signal an alarm once said detector detects the presence of an electrical field equal or above a predetermined strength value.

Description

P208950.lE.01 1 ELECTRICAL FIELD DETECTING SYSTEM Field of the Invention The present invention relates to an electrical ﬁled detecting system for sensing the electric field around a high-voltage facility.

Background to the Invention Personal high voltage detectors speciﬁcally designed to alert people working in high voltage facilities are known. For example, people working in high voltage substation are subjected to the risk of being exposed to strong electromagnetic ﬁelds. In a live substation environment, the substation owners set up safe working distances and close proximity distance to live conductors, these distances are generally set by the voltage on the conductor, for example for 10kV it could be 750mm and for 38kV it could be 1.5m. These close proximity rules can be less if the conductors are behind metal earthed screens. In nearly all substations, it would be the persons hands that are most likely to breach the close proximity rules because the hands are often closest to the live facilities when working. in order to prevent electric shock, the staff are generally equipped with a bracelet type high voltage detector which signals an alarm once the user's hand is within the close proximity distance. Although there are a number of wrist worn high voltage detectors available on the market, none are ideal for a live substation environment for a number of reasons. One reason is that the person’s hand with nigh voltage detector on can be within the safe distance from live conductors whilst other parts of the person’s body can breach the close proximity boundary.

In view of the above, it is an object of the present invention to alleviate and mitigate the above disadvantages.

Summary of the Invention According to a first aspect, the present invention provides an electrical field detecting system comprising a pair electrical field detectors, said detectors being conﬁgured to be worn simultaneously on a user's arms or wrists, one detector on each said arm or wrist; and each detector being configured to signal an alarm once said detector detects the presence of an electrical field equal or above a predetermined strength value.

The predetermined strength of the electrical field is preferably the strength present within a speciﬁed distance from a conductor, the conductor having a predetermined voltage across it.

In one instance, the predetermined voltage can be 10kV and the predetermined distance can F’208950.lE.01 2 be 750mm. predetermined distance can be 1.5m.

In another instance, the predetem1ined voltage can be 38kV and the With existing single detectors, if a person’s amis were wide apart, there is a possibility that the arm not having a detector on could be in contact with a 10kV conductor while the other am with the detector on it could be spaced from the conductor by a distance over 750mm as most people's arms when wide apart would cover the distance of over 750mm. in this case, the detector will not be activated and the person can receive an electric shock. The same situation is also possible with 38kV conductors because some peopIe’s arms could cover the length of over 1.5m when wide apart. By providing detectors on both anns, the present invention solves this problem.

Preferably, each detector is provided with a fastener for wearing the detector on the user's arm or wrist. The fastener may be provided. for example, in the form of a band or a bracelet, but the invention is not limited thereto. The band may be an elastic band. Preferably the fastener is adapted to be worn on a user’s wnst.

Advantageously, each detector is configured to measure electric field and, preferably, not electromagnetic field. Without current flow there is no magnetic ﬁeld. This arrangement is useful in a situation where a circuit is open and there is no current flow in the conductor, but the conductor still has potential to be live at a point of disconnect and back.

Preferably, each detector comprises an antenna for detecting an electric field. Preferably, the antenna is of an inverted cone type having a face in the shape of an inverted cone. This renders each detector’s sensitivity independent of the detector’s orientation with respect to the conductor.

Preferably, each detector is conﬁgured so that the sensitivity of each detector, i.e. the electrical ﬁeld strength at which the detector signals an alarm, can be adjusted by changing firmware settings of the detector.

The alarm may be an audio alarm, e.g. sound, a visual signal, eg. a flashing light, tactile, e.g. vibration or a combination thereof.

Each detector is preferably battery-powered.

P208950.lE.01 3 According to a second aspect, the invention provides a method of operating an electrical field detecting system, the method comprising the steps of: providing a pair electrical field detectors. said detectors being configured to be worn simuitaneously on a user’s arms or wrists, one detector on each said arm or wrist; and each detector being configured to signal an alarm once said detector detects the presence of an electrical ﬁeld equal or above a predetennined strength; wearing the detectors. one detector on each said am or wrist.

The method further comprises the step of causing one of the detectors to signal an alann once said detector detects the presence of an electric ﬁeld equal or above a predetennined strength value within a predetermined distance from a source of the electric field, whilst the other detector is positioned outside the predetennined distance, in an area in which the electric ﬁeld is below the predetermined strength value.

Features of the ﬁrst aspect of the invention can be incorporated into the second aspect of the invention as appropriate and vice versa.

Detailed Description of the Invention The invention will now be described with reference to the accompanying drawings, which show, by way of example only, an embodiment of the invention. In the drawings: Figure 1 is a schematic perspective view of an electrical ﬁeld detecting system in accordance with the invention; and Figure 2 is a schematic perspective view of an antenna used in the electrical field detecting system of Figure 1.

Referring to Figure 1, an electrical ﬁeld detecting system of the invention is indicated generally by reference numeral 1. The electrical field detecting system 1 comprises a pair electrical ﬁeld detectors (3a, 3b). The detectors (3a, 3b) are configured to be worn simultaneously on a user’s anns or wrists, one detector (3a, 3b) on each said arm or wrist. Each detector (3a, 3b) is conﬁgured to signal an alarm once the detector (3a, 3b) detects the presence of an electrical ﬁeld equal or above a predetennined strength value.

The predetennined strength of the electrical field is preferably the strength present within a specified distance from a conductor (not shown in the drawings) having a predetermined voltage across it. In one instance, the predetennined voltage can be 10kV and the P208950.lE.01 4 predetermined distance can be 750mm. In another instance. the predetermined voltage can be 38kV and the predetermined distance can be 1.5m. Other combinations of predetermined voltage and predetermined distance are within the scope of the invention.

With existing single detectors, if a person's arms were wide apart, there is a possibility that the arm not having a detector on could be in contact with a 10kV conductor while the other arm with the detector on it could be spaced from the conductor by a distance over 750mm as most people's arms when wide apart would cover the distance of over 750mm. in this case, the detector will not be activated and the person can receive an electric shock. The same situation is also possible with 38kV conductors because some people’s arms could cover the length of over 1.5m when wide apart. By providing detectors on both arms, the present invention solves this problem.

Each detector (3a, 3b) is provided with a fastener 5 for wearing the detector (3a, 3b) on the user’s arm or wrist. The fastener 5 may be provided, for example, in the form of a band (see Figure 1) or a bracelet, but the invention is not limited thereto. The band may be an elastic band. Preferably the fastener 5 is adapted to be worn on a user's wrist.

Each detector (3a, 3b) is configured to measure electric ﬁeld rather than electromagnetic field.

Since without current ﬂow there is no magnetic ﬁeld, this arrangement is useful in a situation where a circuit is open and there is no current ﬂow in the conductor, but the conductor still has potential to be live at a point of disconnect and back.

Each detector (3a, 3b) comprises an antenna 11 (see Figure 2) for detecting an electric field.

The antenna 11 is preferably of an inverted cone type having a face in the shape of an inverted cone. This renders each detector’s sensitivity independent of the detector’s orientation in relation to the conductor.

Each detector (3a, 3b) is conﬁgured so that the sensitivity of each detector (3a, 3b). i.e. the electrical ﬁeld strength at which the detector signals an alarm, can be adjusted by changing firmware settings of the detector (3a, 3b).

The alarm may be a sound or a visual signal, e.g. a flashing light, or a combination thereof.

For this purpose, the detector (3a, 3b) comprises a speaker 7 and an LED 9. Tactile alarm, e.g. vibration may also be included.

Each detector (3a, 3b) is preferably battery-powered.

P208950.|E.01 In use. the user wears the detectors (3a, 3b). one detector (3a, 3b) on each arm or wrist. As soon as one of the detectors (3a, 3b) detects the presence of an electric ﬁeld equal or above a predetermined strength value within a predetermined distance from a source of the electric field, that detector (3a, 3b) signals an alarm. At the same time, the other detector (3a, 3b) may be positioned outside the predetermined distance, in an area in which the electric ﬁeld is below the predetemlined strength value, and therefore the other detector (3a, 3b) will not signal an alarm. it will be appreciated by those skilled in the art that variations and modiﬁcations can be made without departing from the scope of the invention as deﬁned in the appended claims.

Claims

P208950. |E.01 CLAIMS:

1. An electrical ﬁeld detecting system comprising a pair electrical field detectors, said detectors being conﬁgured to be worn simultaneously on a user’s arms or wrists, one detector on each said arm or wrist; and each detector being conﬁgured to signal an alarm once said detector detects the presence of an electrical ﬁeld equal or above a predetermined strength value.

2. An electrical field detecting system of claim 1, wherein the predetermined strength of the electrical ﬁeld is the strength present within a specified distance from a conductor, the conductor having a predetermined voltage across it; optionally, wherein the predetermined is 10kV and the predetermined distance is 750mm; optionally, wherein the predetermined voltage is 38kV and the predetermined distance is 1500mm; optionally, wherein each detector is provided with a fastener for wearing the detector on the users arm or wrist; optionally, wherein the alarm one of an audio alarm, a visual signal. a tactile alarm, or a combination thereof; optionally, wherein each detector is battery-powered.

3. An electrical field detecting system of claim 1 or claim 2, wherein each detector is conﬁgured to measure electric ﬁeld and not electromagnetic ﬁeld; optionally, wherein each detector is conﬁgured so that the sensitivity of each detector, i.e. the electrical field strength at which the detector signals an alarm, can be adjusted by changing ﬁrmware settings of the detector.

4. An electrical ﬁeld detecting system of any preceding claim, wherein each detector comprises an antenna for detecting an electric ﬁeld; optionally, wherein the antenna is of an inverted cone type having a face in the shape of an inverted cone.

5. A method of operating an electrical ﬁeld detecting system, the method comprising the steps of: providing a pair electrical field detectors, said detectors being conﬁgured to be worn simultaneously on a users arms or wrists, one detector on each said arm or wrist; and P208950.|E.01 7 each detector being conﬁgured to signal an alarm once said detector detects the presence of an electrical ﬁeld equal or above a predetennined strength; wearing the detectors, one detector on each said am or wrist; optionally, wherein the method further comprises the step of causing one of the detectors to signal an alarm once said detector detects the presence of an electric ﬁeld equal or above a predetennined strength value within a predetennined distance from a source of the electric field, whilst the other detector is positioned outside the predetennined distance, in an area in which the electric ﬁeld is below the predetennined strength value.