WO2022243673A1

WO2022243673A1 - Fuse apparatus

Info

Publication number: WO2022243673A1
Application number: PCT/GB2022/051239
Authority: WO
Inventors: Michael Erskine
Original assignee: Advance Technical Systems Limited
Priority date: 2021-05-19
Filing date: 2022-05-17
Publication date: 2022-11-24
Also published as: GB202107183D0; GB2607009A

Abstract

Disclosed herein is a fuse apparatus for connecting a local power distribution circuit to a mains power grid to provide electrical power to the local power distribution circuit from the mains power grid. The fuse apparatus comprises a cut out fuse for electrically connecting an input power line from the mains power grid to the local power distribution circuit and for protecting the local power distribution circuit. The fuse apparatus further comprises mains supply monitoring means. The mains supply monitoring means comprises fault detecting means connectable to the input power line and configured to detect a fault associated with the mains power grid, and alert signal generating means to output an alert signal indicative of a fault being detected in the event the fault detecting means detects a fault.

Description

Fuse Apparatus

Technical Field

The present invention relates to fuse apparatus.

Background

Modern utility infrastructure is commonly divided into several parts, each part the responsibility of a different party.

For example, increasingly in the UK and elsewhere, local electrical power distribution (comprising substations, local power distribution lines and cables and final step down transformers) are the responsibility of either “Distribution Network Operators” (DNOs) or “Independent Distribution Network Operators (IDNOs)”.

At present, there are six DNOs and 14 IDNOs across the UK, each with responsibility for a number of different Networks. DNOs are typically responsible for infrastructure within a specific geographical area, whereas IDNOs may be responsible for infrastructure across several geographic areas.

A common problem for both DNOs and IDNOs arises when a fault is reported by an occupant of premises. Without inspection by an engineer, it is difficult to determine if the fault is with the infrastructure owned by the DNO or IDNO (for example, the local low voltage or high voltage power distribution network, including mains and service cables, transformers or link boxes), or due to a fault with other electrical equipment at the premises itself (for example, a faulty consumer unit, faulty electrical equipment inside the premise or a faulty electricity meter). A faulty consumer unit or faulty electrical equipment inside the premise is typically the responsibility of the occupant, and a faulty electricity meter is typically the responsibility of the energy supplier who charges the occupant for use of the electricity.

An occupant will typically report faults by telephone, and even with expert guidance provided by a remote operator, occupants cannot be relied on to determine the cause of the fault or at least exclude the possibility that it is a fault for which the DNO or the IDNO is responsible.

DNOs and IDNOs are typically under strict obligations (in the UK for example - “Guaranteed Standards Of Service” (GSOS)) to ensure that power interruptions due to faults in equipment for which they are responsible are remedied in a timely manner. When these obligations are not met (for example, the terms specified in the GSOS are not met), the DNO or IDNO are typically subject to financial and other penalties. Often, the longer the power interruption, the greater the financial penalty. Failing to meet these obligations can also damage a DNO or IDNO’s reputation.

Consequently, DNOs and IDNOs are typically obligated to send an engineer to investigate a reported power cut at a premises, even if it subsequently transpires that the fault was with the internal supply and/or equipment for which the DNO or IDNO is not responsible. The cost, in both money and time, of sending out engineers to investigate all faults in this way can be substantial. It can also be a frustrating experience for an occupant who may have to wait a substantial period of time without power, only to find out that the DNO or IDNO cannot fix the fault (because the fault is not with any equipment for which the DNO or IDNO is responsible), and that an electrician must be called.

Summary of the Invention

In accordance with a first aspect of the invention, there is provided a fuse apparatus for connecting a local power distribution circuit to a mains power grid to provide electrical power to the local power distribution circuit from the mains power grid. The fuse apparatus comprises a cut out fuse for electrically connecting an input power line from the mains power grid to the local power distribution circuit and for protecting the local power distribution circuit. The fuse apparatus further comprises mains supply monitoring means. The mains supply monitoring means comprises fault detecting means connectable to the input power line and configured to detect a fault associated with the mains power grid, and alert signal generating means to output an alert signal indicative of a fault being detected in the event the fault detecting means detects a fault.

Optionally, the fault detecting means comprises a voltage sensor.

Optionally, the voltage sensor is configured to detect an abnormal voltage associated with a fault with mains power grid.

Optionally, the alert signal generating means comprises output display means for generating a visual indication of a fault being detected.

Optionally, the output display means comprises one or more indicator lights.

Optionally, the output display means comprises a display screen.

Optionally, the mains supply monitoring means comprises a control unit connected to the fault detecting means and configured to receive an output signal from the fault detecting means, process the output signal, and generate a control signal controlling the alert signal generating means to generate the output alert signal.

Optionally, the control unit is further configured to process the output signal and generate diagnostic data indicative of characteristics of a detected fault.

Optionally, the alert signal generating means is configured to output the diagnostic data.

Optionally, the alert signal generating means further comprises a data transceiver configured to communicate the alert signal and/or output diagnostic data to a remote receiver for processing by a remote computing system. Optionally, the data transceiver is a wireless data transceiver.

Optionally, the fuse apparatus comprises a modified cut out fuse unit incorporating the mains supply monitoring means.

Optionally, the modified cut out fuse unit is for a domestic premises and comprises an outer housing corresponding to a conventional domestic cut out fuse unit.

Optionally, the fuse apparatus comprises a first unit incorporating the cut out fuse unit and a second unit incorporating the mains supply monitoring means.

Optionally, the fuse apparatus comprises a battery for powering the mains supply monitoring means.

Optionally, the control unit is connected to a memory unit, said control unit configured to generate fault duration data indicative of a duration of a detected fault and to store said fault duration data in the memory unit for subsequent retrieval.

Optionally, the fault detecting means further comprises an impedance sensor configured to detect an abnormal impedance associated with a fault with an earth connection of the input power line from the mains power grid

Optionally, the alert signal generating means is configured to output an alert signal indicative of an abnormal impedance in the event the impedance sensor detects an abnormal impedance associated with a fault with the earth connection of the input power line from the mains power grid.

Optionally, the control unit is configured to receive, via the data transceiver, a known fault data signal indicative of a known fault associated with the mains power grid, said alert signal generating means is configured to output an alert signal indicative of a known fault present in the mains power grid.

Cut out fuse units are standard components in electrical supply equipment for connecting premises, such as domestic or commercial dwellings, to the “mains” electrical power supply network. For a residential supply, a cut out fuse unit typically comprises a wall-mountable housing. For a commercial/industrial (i.e. non-residential supply), a cut out fuse unit typically comprises a free standing housing.

In both cases, a cut out fuse unit comprises a suitable fuse (or fuses), input connections for receiving a mains power line and mains neutral line, and output connections for connecting to the local live line and local neutral line. A ground line connection is also often provided.

In many settings, a cut out fuse unit demarcates a change in responsibility for equipment. For example, components connected to the cut out fuse and associated with the power distribution circuit within the premises are typically either the responsibility of proprietor of the premises (for example the consumer unit and all onward connections to electrical power outlets, fixed appliances and so on) or a utility company from whom the proprietor purchases electricity (for example the electricity meter). On the other hand, components such as power cables, power lines and local transformers that are connected to the cut out fuse unit that provide electrical power to the premises will most likely be the responsibility of another party such as a DNO or IDNO.

Advantageously, in settings in which responsibility is demarcated as described above, by incorporating or connecting a mains supply monitoring means to the cut out fuse for monitoring the status of the electrical power provided from the mains electrical power supply network, the responsibility for remedying power outages experienced in a location connected to the mains electrical power supply network via the cut out fuse can be immediately determined. If the mains supply monitoring means indicates a fault with the mains electrical power supply network, then remedying the fault is likely to be the responsibility of, for example, an IDNO. On the other hand, if there is no fault indication from the mains supply monitoring means, then remedying the fault is likely to be the responsibility of another party, for example a premises proprietor.

In certain embodiments, the mains supply monitoring means provides a simple visual output, for example one or more indicator lights or a display screen that displays a simple status message. Advantageously, such simple visual output can be readily comprehended by, for example an occupant of a premises. In this way, when reporting a fault, for example by telephone, the occupant can be guided by an operative to locate the cut out fuse and associated mains supply monitoring means and report back to the operative if a fault is indicated. In this way, for example, it can be determined whether or not a party, such as an IDNO is likely to be responsible for remedying a power outage and whether or not it is necessary to send an engineer (and incur the associated cost).

Various further features and aspects of the invention are defined in the claims.

Brief Description of the Drawings

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings where like parts are provided with corresponding reference numerals and in which:

Figure 1 provides a simplified schematic diagram depicting an arrangement including a modified cut out fuse unit in accordance with certain embodiments of the invention;

Figure 2 provides a simplified schematic diagram depicting an arrangement corresponding to that shown in Figure 1 except that a modified cut out fuse unit and mains supply monitoring unit are provided where the mains supply monitoring unit is located outside of the modified cut out fuse unit;

Figure 3a provides a simplified schematic diagram depicting a mains supply monitoring unit arranged in accordance with certain embodiments of the invention;

Figure 3b provides a simplified schematic diagram depicting a mains supply monitoring unit arranged in accordance with certain embodiments of the invention; Figure 3c provides a simplified schematic diagram depicting a mains supply monitoring unit arranged in accordance with certain embodiments of the invention;

Figure 4 provides a simplified schematic diagram of an electrical Power Distribution system; Figure 5 provides a schematic diagram depicting an electric vehicle charging facility including a fuse apparatus in accordance with an exemplary embodiment of the invention, and

Figure 6 provides a simplified schematic diagram modified cut out fuse unit in accordance with certain embodiments of the invention. Detailed Description

Figure 1 provides a simplified schematic diagram depicting an arrangement including a modified cut out fuse unit 101 in accordance with certain embodiments of the invention.

The modified cut out fuse unit 101 is connected to a meter 102 which is further connected to a consumer unit 103 via a live line cable 104 and neutral line cable 105. The arrangement depicted in Figure 1 corresponds to components of a conventional electric supply system provided in, for example, a domestic premises.

Electrical power is provided via an input power line provided by a single phase mains “service” cable 106, through the modified cut out fuse unit 101 and on into the local power distribution circuit via the meter 102 and the consumer unit 103. The consumer unit 103 is connected to appliances and electrical outlets in the premises via the local distribution circuit or circuits (not shown) which a cut out fuse of the cut out fuse unit 101 serves to protect.

The single phase mains service cable 106 typically comprises an inner core providing a mains power line 107. The mains power line 107 includes a live line, neutral line and an earth connection line.

The single phase mains service cable 106 is fed electrical power from a mains electrical power supply network (a mains power grid).

The single phase mains service cable 106 is connected to the modified cut out fuse unit 101 via the mains power line 107. Specifically, the live line and neutral line of the mains power line 107 are input to a cut out fuse 108 modified cut out fuse unit 101.

The output of the cut out fuse 108 is connected to the separate neutral line cable 105 and the separate live line cable 104.

The modified cut out fuse unit 101 further comprises a mains supply monitoring unit 109. The mains supply monitoring unit 109 comprises a voltage sensor 110 which is connected to the mains power line 107 via a signal line and to a ground connection 111. Although not shown in Figure 1, typically the ground connection 111 is connected to the earth connection line of the mains power line 107. The voltage sensor 110 is further connected to a control unit 112. The control unit 112 has running thereon a supply fault detection function and is connected to an indicator light unit 113 which comprises a green indicator light 114 and red indicator light 115, provided, for example, by one or more suitable LEDS.

The components of the mains supply monitoring unit 109 are independently powered by a battery 116.

In use, the voltage sensor 110 is connected to the live line of the mains power line 107 and configured to monitor the mains voltage provided by the mains power line 107. The voltage sensor 110 generates a corresponding sensor signal which is input to the control unit 112.

The sensor signal can be any suitable signal that corresponds to a suitable property of the voltage of the mains power line 107. For example, depending on the configuration of the voltage sensor 110 this could be a digital or analogue value indicative of an RMS value of the voltage and/or frequency of the voltage.

The supply fault detection function running on the control unit 112 is configured to process the sensor signal to determine whether or not the sensor signal is indicative of a fault.

Generally, the supply fault detection function is configured to identify if the sensor signal indicates a voltage level on the live line of any mains power line which is abnormal, that is, substantially different from normal operating voltage levels. In the UK, for example, an abnormal voltage level would be anything substantially different (more than +10% & -6%) from an RMS value of 230V and a frequency of 50Hz.

A typical mains power supply fault that the supply fault detection function is configured to detect would be the absence of any supply voltage indicating a total power cut.

In the event that the supply fault detection function running on the control unit 112 determines that the mains voltage detected by the voltage sensor 110 is indicative of a fault, the control unit 112 is configured to generate a control signal which is communicated to the indicator light unit 113.

The control signal controls the indicator light unit 113 to illuminate the red indicator light 115, indicating that a fault has been detected. During operation when no fault is detected by the supply fault detection function, the control unit 112 controls the indicator light unit 113 via a suitable control signal to illuminate the green indicator light 114.

In this way, a visual alert signal is provided by the indicator light unit 113. This visual alert signal indicates whether, or not, a fault has been detected in the power supply provided from the mains via the single phase mains service cable 106.

In the arrangement shown in Figure 1, in the event of a loss of power to the electrical appliances and outlets connected to the consumer unit 103, a visual indication is provided by the indicator light unit 113 showing that a fault has been detected. This visual indication immediately indicates whether the source of the fault is from the power supply provided by the mains power line of the mains service cable 106, or likely to be associated with components connected to the modified cut out fuse unit 101 , such as the meter 102 or consumer unit 103.

As can be seen from Figure 1, the mains supply monitoring unit 109 comprising the voltage sensor 110, control unit 112 and indicator light unit 113, is incorporated within the modified cut out fuse unit 101. In this way, the modified cutout fuse unit 101 incorporating the mains supply monitoring unit 109 forms a single unit. Advantageously, in such embodiments, the conventional form factor of cut out fuse units can be retained. That is, the modified cut out fuse unit comprises an outer housing corresponding to a conventional domestic cut out fuse unit. In this way, such modified cut out fuse units can be readily integrated into existing arrangements, such as cabinets containing components such as the electricity meter and consumer unit.

However, in other embodiments, different configurations are possible. For example, in certain embodiments, the cut out fuse unit and the mains supply monitoring unit can be provided by separate, but suitably connected units. Figure 2 provides a simplified schematic diagram depicting an arrangement corresponding to that shown in Figure 1 except that a modified cut out fuse unit 201 and mains supply monitoring unit 202 are provided wherein the mains supply monitoring unit 202 is located outside of the modified cut out fuse unit 201.

The voltage sensor 110 of the mains supply monitoring unit 202 is connected to the mains power line 107 of the modified cut out fuse unit 201 via a connecting signal line 205. As will be understood, the mains supply monitoring unit 202 and the modified cut out fuse unit 201 can be physically connected and electrically connected (via the signal line 205) via any suitable connecting interface. The connecting signal line 205 provides connection via a first connection interface 203 provided on the modified cut out fuse unit 201 and a second connection interface 204 provided on the mains supply monitoring unit 202. Other than the mains supply monitoring unit 202 being located outside of the modified cut out fuse unit 201, the modified cut out fuse unit 201 and mains supply monitoring unit 202 operate in substantially the same way as the modified cut out fuse unit 101 and mains supply monitoring unit 109 described with reference to Figure 1

In the embodiments described with reference to Figures 1 and 2, the status of the electrical power supply provided via the mains power line 107 is provided by a simple “visual” alert from the indicator light unit 113. That is, the status of the electrical power supply can be determined by a person looking at the modified cut out fuse unit. However, in certain embodiments an alert signal can be provided in other ways.

Figure 3a provides a simplified schematic diagram depicting a mains supply monitoring unit 301 arranged in accordance with certain embodiments of the invention. In keeping with the examples described above, the mains supply monitoring unit 301 comprises a voltage sensor 110 and battery 116. However, rather than a simple indicator light unit the mains supply monitoring unit 301 comprises a display screen 303. The mains supply monitoring unit 301 further comprises a wireless transceiver 304.

In use, a control unit 302 is provided that is configured to receive the output signal from the voltage sensor 110. In the event that the voltage detected by the voltage sensor 110 is indicative of a fault, a supply fault detection function running on the control unit 302 is configured to send a control signal to the display screen 303 which controls the display screen 303 to output a visual alert signal, for example, text reading “FAULT DETECTED”. During operation, when the output from the voltage sensor 110 indicates a normal power supply from the mains power supply, the control unit 302 is configured to generate a control signal which controls the display screen 303 to generate a corresponding indication, for example, text reading “NO FAULT DETECTED”.

Further, in use, in the event that the sensor signal from the voltage sensor 110 is indicative of a fault, the supply fault detection function running on the control unit 302 is configured to generate a control signal which is communicated to the wireless transceiver 304, responsive to which the wireless transceiver 304 is configured to transmit to a wireless data signal indicative of a detected fault. The wireless data signal is typically received by a base station 305 and communicated via a suitable data network 306 to a remote computing system 307. As will be understood, in this way, faults detected by the mains supply monitoring unit 301 can be remotely monitored. For example, the length of time that the power supply to a premises is interrupted can be remotely monitored.

The wireless transceiver 304 can be provided by any suitable wireless transceiver as is known in the art.

For example, in one implementation, the wireless transceiver 304 can be configured to communicate data to and from a cellular mobile telecommunications network. In such an example, the base station 305 would typically be provided by a base station of a cellular mobile telecommunications network and the data network 306 would be provided by a telecommunications network to which the remote computing system 307 would also be connected.

In another implementation, the wireless transceiver 304 can be provided by a short-range wireless transceiver operating in accordance with a short range radio protocol such as Bluetooth or Wi-Fi, for example. In such implementations, the base station 305 may be provided by a suitable receiver connected to a “network access point” connected to the data network 306 provided by the internet to which the remote computing system 307 is also attached.

In alternative embodiments, instead of, or in addition to, the wireless transceiver 304, a “wired” transceiver may be provided and connected, via a suitable connection (for example an ethernet connection) to the data network 306.

In certain embodiments, the control unit 302 has running thereon a characterisation function which is configured to process the signal from the voltage sensor 110 to characterise any fault detected. Specifically, the characterisation function running on the control unit 302 can be configured to identify different types of faults.

For example, if the voltage sensor 110 indicates that no voltage is detected on the mains power line, this would be indicative of a total failure of the mains supply due, for example, to a breaker circuit tripping in the substation from which the mains power line originated. Alternatively, if the voltage sensor 110 indicates that the voltage on the mains power line is unstable, this may be indicative of a loading imbalance elsewhere on the network. Thus, in certain embodiments, the control unit 302 is configured to process the sensor signal from the voltage sensor 110 and generate a corresponding control signal which when received by the display screen 303 controls the display screen 303 to output the diagnostic data, for example in the form of text, for example “NO SUPPLY VOLTAGE DETECTED” or “UNSTABLE SUPPLY VOLTAGE”.

Similarly, the control unit 302 may be further configured to generate a control signal which is communicated to the wireless transceiver 304, said control signal controlling the wireless transceiver 304 to generate a wireless data signal including diagnostic data which is communicated to the remote computing system 307 via the base station 305 and data network 306.

Example use of fuse apparatus in accordance with certain embodiments of the invention is described further with reference to Figure 4.

Figure 4 provides a simplified schematic diagram of an electrical power distribution system. Electrical power is generated at a power station 401 which is then transmitted via high voltage transmission lines 402 to a substation 403. At the substation 403 the electrical power is reduced in voltage and transmitted onwards via a low voltage local transmission system 404 to a final transformer 405. The electrical power is then reduced in voltage again via the final transformer 405. Low voltage electrical power is then transmitted from the final transformer 405 via cables into a plurality of premises 406a, 406b, 406c, for example individual houses.

The infrastructure associated with the substation 403, such as, the low voltage local transmission system 404 and final transformer 405 are, in certain settings, the responsibility of an independent distribution network operator (IDNO).

Each individual premises is provided with a modified cut off fuse 407a, 407b, 407c, for example of the type described with reference to Figure 1.

Typically, in the event of a power cut in one of the premises 406a, 406b, 406c, an occupant is directed to contact the IDNO, typically by telephone.

Conventionally, if the power cut cannot be attributed to an already identified fault (either a known fault in the network, or a fault in the equipment in the premises), the IDNO is obliged to send an engineer to the premises to investigate, even if it relates to a fault for which the IDNO is not responsible (for example, a fault with an electricity meter, consumer unit or other part of the equipment in the premises).

However, in accordance with certain embodiments of the invention, the occupant can be guided (for example, by an operative by telephone) to locate the modified cut off fuse 407a, 407b, 407c and report back whether or not the mains supply monitoring unit indicates a fault with the supply. As will be appreciated, in certain examples this is as simple as identifying whether a red or green light is illuminated and/or reading a simple message from a display screen. In the event that the occupant reports a fault is indicated, then the IDNO can send an engineer to investigate the problem. In the event that the occupant reports no fault is indicated, the IDNO need not send an engineer because the fault is not the responsibility of the IDNO. In such circumstances, for example, where an occupant is speaking to an operative by telephone, the operative can suggest that the occupant contact an electrician.

As will be understood, in examples in which a wireless transceiver is provided with the main supply monitoring unit, the presence or absence of a fault in the network supplying the premises can be determined remotely and independently (or in conjunction with) information provided by the occupant of the premises.

Further, in examples in which the control unit is configured to generate diagnostic data, when this diagnostic data is received (either via the wireless data signal or reported by the occupant from what is displayed, for example, on a display screen), this can be used by operatives of the IDNO to understand more about the nature of the fault.

Mains supply monitoring apparatus arranged in accordance with certain embodiments of the invention can be provided with further functionality.

Figure 3b provides a simplified schematic diagram of a mains supply monitoring apparatus 305 arranged in accordance with an embodiment of the invention which corresponds to the mains supply monitoring apparatus 301 described with reference to Figure 3a, except that the mains supply monitoring apparatus 305 shown in Figure 3b further comprises a memory unit 308 connected to the control unit 302.

In use, the control unit 302 has running thereon a fault duration monitoring function which is configured to monitor the length of time (duration) of a power fault (for example, the period of time that the premises is without power due to a fault in the mains supply connected to the premises). The fault duration monitoring function is configured to generate fault duration data which specifies the length of periods of time during which the control unit 302 detects that there is a fault with the mains power supply. The control unit 302 is configured to store this fault duration data in the memory unit 308.

In the event that an occupant reports a fault, the fault duration data can be retrieved from the memory unit 308 (and communicated, for example, to the remote computing system 307) to verify the length of the time that there was a fault with the power supply from the mains cable to the premises.

The fault duration data generated in this way can be used, for example, to determine whether or not the occupant of the premises qualifies for compensation and, in certain examples, if so, how much compensation. Such a technique for verifying the length of time that a fault has persisted using data generated at the mains supply monitoring apparatus may be preferable to relying on what an occupant reports, particularly if the occupant stands to gain financially the greater the duration of the fault.

Figure 3c provides a simplified schematic diagram depicting a mains supply monitoring apparatus 309 in accordance with certain embodiments of the invention, which corresponds to that shown in Figure 3b, except that the mains supply monitoring apparatus 309 further comprises an impedance sensor 310 which, in use, is connected to the earth connection line of the mains power line to which the mains supply monitoring apparatus 309 is incorporated or connected. In such embodiments, the supply monitoring apparatus 309 is configured to monitor the “earth loop impedance” associated with the earth connection line of the mains power line.

The impedance sensor 310 is configured to generate an output sensor signal which is input to the control unit 302. The control unit 302 is configured to process this sensor signal to determine if the impedance detected by the impedance sensor 310 is indictive of a fault with the earth connection provided by the earth connection line of the mains power line.

As is known, in the event of a fault with the earth connection, the “earth loop impedance” provided by the earth connection line of the mains power line may be sufficiently high to potentially prevent the cut out fuse tripping in the event of a current surge.

In such embodiments, the control unit 302 has running thereon an earth loop impedance monitoring function which continuously or periodically processes the sensor signal from the impedance sensor 310 to determine if the sensor signal is abnormal and indicative of a fault with the earth connection provided by the earth connection line.

A typical abnormal impedance level is an impedance of the earth connection line of the mains power line which is above a predetermined safe level. In the event that the earth loop impedance monitoring function detects that the impedance of the earth connection provided by the earth connection line is above the predetermined safe level, the control unit 302 is configured to control the display screen 303 to display a visual alert, for example a message reading “WARNING -LOW/HIGH EARTH LOOP IMPEDANCE”.

Additionally, or alternatively, the control unit 302 may be configured to generate a faulty earth connection data signal which is communicated from the wireless transceiver 304 via the data network 306 to the remote computing system 307. In this way an appropriate alert can be generated remotely if a faulty earth connection is detected and suitable remedial action taken. For example, engineers could be dispatched to inspect the mains power line connected to the premises where the faulty earth connection has been detected.

Mains supply monitoring apparatus arranged in accordance with certain embodiments of the invention can be configured to receive data, and, in particular, data in relation to the known status of the network, such as detected faults or power outages due to repairs or maintenance of the network being undertaken.

For example, returning to Figure 3a, in the event that a fault is detected by, for example an operator of the power network (for example a DNO or IDNO), a fault alert function operating on the remote computing system 307 can be configured to generate and communicate a corresponding known fault alert data signal to the mains supply monitoring apparatus 301 via the data network 306. The known fault alert data signal is indicative of there being a known fault in the network.

The control unit 302 of the mains supply monitoring apparatus 301 is configured to receive this known fault alert data signal via the wireless transceiver 304 and, responsive to which, control the display screen 303 to generate a visual alert signal indicating that there is a known fault on the network. Such a visual alert signal might typically be in the form of text such as “KNOWN FAULT IN SUPPLY NETWORK”.

In other embodiments, for example where the mains supply monitoring apparatus is equipped with an indicator light unit, such an indicator light unit could comprise a third LED which illuminates in the event that the mains supply monitoring apparatus receives the fault alert data signal.

In this way, an occupant of a property can be readily alerted that a fault with their electrical power supply is likely to be the result of a fault which is already known about (and, potentially, being dealt with). This might typically reassure the occupant and reduce the likelihood that they immediately contact network operator in the event of a fault which the network operator already knows about.

Fuse apparatus according to examples of the invention can be used in settings other than domestic premises.

Figure 5 provides a schematic diagram depicting an electric vehicle charging facility 501 comprising a plurality of electric vehicle charging units 502a, 502b, 502c, for charging electric vehicles. A facility power distribution unit 503 of the electric vehicle charging facility 501 is provided with a modified cut out fuse unit 504 of the type described above. That is, the modified cut out fuse unit 504 comprises a mains supply monitoring unit which is able to identify faults associated with the power supply provided by a power line 505 from the mains power supply network.

The modified cut out fuse unit 504 is provided with a wireless transceiver for communicating a wireless signal comprising fault data and diagnostic data to a remote computing system 508 via a base station 506 and data network 507.

The use of a modified cut out fuse unit 504 with means to communicate fault data to a remote computing system 508 may provide a particular advantage because a power network operator (or any party responsible for maintaining the power network provided to the electric vehicle charging facility 501) can independently identify faults that it is responsible for, irrespective of whether or not they have yet been reported by an operator of the electric vehicle charging facility 501 who might typically be a different commercial party.

In the examples described above, fault detecting means for detecting a fault with the mains electrical power supply network is provided by a suitable voltage sensor connected to the mains power line input to the fuse of the cut out fuse unit.

In the examples described above, alert signal generating means have been described in terms of light indicator units, display screens and wireless transceivers. It will be understood that any suitable alert signal generating means can be used, for example alert signal generating means that emit a sound when fault is detected such as an alarm tone or pre-recorded message. Moreover, mains supply monitoring means can comprise any one or any suitable combination of alert signal generating means, including any one or any combination of the alert signal generating means described above.

In the examples described above, mains supply monitoring units have been described with reference to cut out fuses receiving and providing a single phase power supply via a single mains service cable. However, embodiments of the invention can also be implemented with a mains supply monitoring unit connected to or incorporated in a cut out fuse configured for receiving and distributing a three phase power supply.

Figure 6 provides a simplified schematic diagram depicting a cut out fuse unit 601 arranged in accordance with certain embodiments of the invention.

As can be seen, the cut out fuse unit 601 is configured to receive a three phase service cable 602 which contains a mains power line comprising a first supply cable 603a providing a first phase power line, a second supply cable 603b providing a second phase power line and a third supply cable 603c providing a third phase power line.

The first supply cable 603a is connected to a first cut out fuse 604a, the second supply cable 603b is connected to a second cut out fuse 604b and the third supply cable 603c is connected to a third cut out fuse 604c. The first fuse 604a is connected to a first phase output line 605a, second fuse 604b is connected to a second phase output line 605b and third fuse 604c is connected to a third phase output line 605c.

The cut out fuse unit 601 includes a mains supply monitoring unit 301 substantially as described with reference to Figure 3a. However, the voltage sensor 607 of mains supply monitoring apparatus 301 is connected, via a first signal line 606a to the first supply cable 603a, via a second signal line 606b to the second supply cable 603b and via a third signal line 606c to the third supply cable 603c. Although the voltage sensor 607 is depicted as a single unit, typically the voltage sensor 607 may comprise three separate voltage sensor units, each connected to one of the supply cables.

In use, the voltage sensor 607 is configured to generate output sensor signals indicative of the voltage detected on each of the supply cables. These output signals are received by the control unit 302 and as described above. A supply fault detection function running on the control unit 302 is configured to identify if the voltage sensor 607 has detected voltage levels indicative of a fault. For example, if the voltage sensor 607 indicates that no voltage, or a voltage that is substantially lower than the intended supply voltage, is detected across the three phase power lines, this would be indicative of a fault with the mains supply. Such a fault, might be due, for example, to a breaker circuit tripping in the substation from which the mains power line originated. If the voltage sensor 607 indicates that no voltage, or a voltage that is substantially lower than the intended supply voltage, is detected across only one or two of the phases of the power line, this would be indicative of a phase loss from the mains supply. Phase loss in a power line, also referred to as “single phasing” can cause unsafe operation, and failure, of equipment being powered by said power line. If the voltage sensor 607 indicates that the measured voltages, of one or more of the phases of the power line, substantially deviates from the intended supply voltage, this would be indicative of uneven loading on one or more of the phase power lines. Alternatively, if the voltage sensor 607 indicates that the voltage detected on one or more of the three phase power lines is unstable, this may be indicative of a loading imbalance elsewhere on the network. Acceptable levels of deviation, and intended supply voltage can be determined by IDNOs or DNOs.

If the supply fault detection function running on the control unit 302 identifies that the voltage sensor 607 has detected voltage levels indicative of a fault, the control unit 302 is configured to send a control signal, to the display screen 303, which controls the display screen 303 to output a visual alert signal.

The visual alert signal could be, for example, text reading “FAULT DETECTED”. As described above, alternatively or additionally, the control unit 302 may be configured to generate a control signal which is communicated to the wireless transceiver 304, responsive to which the wireless transceiver 304 is configured to transmit a wireless data signal indicative of a detected fault to a remote computing system.

In the examples described above, fuse apparatus in accordance with embodiments of the invention have been described located substantially at the “end point” of a distribution network - i.e. at the point where electrical power is consumed (e.g. at a domestic, commercial or industrial premises). However, in certain examples, a fuse apparatus comprising a cut out fuse and a mains supply monitoring unit could be located on the distribution side, for example within a substation at the point where a higher voltage input is converted to a lower voltage output. For example, with reference to Figure 4, a suitably adapted fuse apparatus in accordance with certain embodiments of the invention could be incorporated in the substation 403. Control units for use in mains supply monitoring units in accordance with embodiments of the invention can be provided by any suitable means which would be readily apparent to the skilled person. For example, a suitable control unit could be provided by a unit comprising one or more suitably programmed microprocessors with associated memory and suitable input and output interfaces. Specifically, such a microprocessor can be programmed to implement the supply fault detection function described above. In embodiments in which further functionality is provided, the microprocessor can be programmed to implement the characterisation function and/or the fault duration monitoring function and/or the impedance monitoring function.

Specifically, such a dedicated circuit can be physically configured to implement the supply fault detection function described above. In embodiments in which further functionality is provided, such a dedicated circuit can be physically configured to implement the characterisation function and/or the fault duration monitoring function and/or the impedance monitoring function.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in 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 particular claim containing such introduced claim recitation to embodiments 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 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 be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations).

It will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope being indicated by the following claims.

Claims

1. Fuse apparatus for connecting a local power distribution circuit to a mains power grid to provide electrical power to the local power distribution circuit from the mains power grid, said fuse apparatus comprising: a cut out fuse for electrically connecting an input power line from the mains power grid to the local power distribution circuit and for protecting the local power distribution circuit, and a mains supply monitoring means, said mains supply monitoring means comprising: fault detecting means connectable to the input power line and configured to detect a fault associated with the mains power grid, and alert signal generating means to output an alert signal indicative of a fault being detected in the event the fault detecting means detects a fault.

2. Fuse apparatus according to claim 1, wherein the fault detecting means comprises a voltage sensor.

3. Fuse apparatus according to claim 2, wherein the voltage sensor is configured to detect an abnormal voltage associated with a fault with mains power grid.

4. Fuse apparatus according to any previous claim, wherein the alert signal generating means comprises output display means for generating a visual indication of a fault being detected.

5. Fuse apparatus according to claim 4, wherein the output display means comprises one or more indicator lights.

6. Fuse apparatus according to claim 4 or 5, wherein the output display means comprises a display screen.

7. Fuse apparatus according to any previous claim, wherein the mains supply monitoring means comprises a control unit connected to the fault detecting means and configured to receive an output signal from the fault detecting means, process the output signal, and generate a control signal controlling the alert signal generating means to generate the output alert signal.

8. Fuse apparatus according to claim 7, wherein the control unit is further configured to process the output signal and generate diagnostic data indicative of characteristics of a detected fault.

9. Fuse apparatus according to claim 8, wherein the alert signal generating means is configured to output the diagnostic data.

10. Fuse apparatus according to claim 8 or 9, wherein the alert signal generating means further comprises a data transceiver configured to communicate the alert signal and/or output diagnostic data to a remote receiver for processing by a remote computing system.

11. Fuse apparatus according to claim 10, where the data transceiver is a wireless data transceiver.

12. Fuse apparatus according to any previous claim, comprising a modified cut out fuse unit incorporating the mains supply monitoring means.

13. Fuse apparatus according to claim 11, wherein the modified cut out fuse unit is for a domestic premises and comprises an outer housing corresponding to a conventional domestic cut out fuse unit.

14. Fuse apparatus according to any of claims 1 to 12, comprising a first unit incorporating the cut out fuse unit and a second unit incorporating the mains supply monitoring means.

15. Fuse apparatus according to any previous claim, comprising a battery for powering the mains supply monitoring means.

16. Fuse apparatus according to any of claims 7 to 15, wherein the control unit is connected to a memory unit, said control unit configured to generate fault duration data indicative of a duration of a detected fault and to store said fault duration data in the memory unit for subsequent retrieval.

17. Fuse apparatus according to claim 3, wherein the fault detecting means further comprises an impedance sensor configured to detect an abnormal impedance associated with a fault with an earth connection of the input power line from the mains power grid.

18. Fuse apparatus according to claim 17, wherein the alert signal generating means is configured to output an alert signal indicative of an abnormal impedance in the event the impedance sensor detects an abnormal impedance associated with a fault with the earth connection of the input power line from the mains power grid.

19. Fuse apparatus according to claim 10, wherein the control unit is configured to receive, via the data transceiver, a known fault data signal indicative of a known fault associated with the mains power grid, said alert signal generating means is configured to output an alert signal indicative of a known fault present in the mains power grid.