Patent Publication Number: US-2023140911-A1

Title: Electrical socket system and method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation application of co-pending U.S. patent application Ser. No. 17/443,282, filed on Jul. 23, 2021, which claims priority pursuant to 35 U.S.C. 119(a) to United Kingdom Patent Application No. 2101308.1, filed Jan. 29, 2021, both of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure relates to an electrical socket system and method, and particularly, although not exclusively, relates to an electrical socket system and method in which a temperature gradient is monitored and used to trigger an alarm event. 
     BACKGROUND OF THE INVENTION 
     Traditional smoke detectors are well known and widely used. However, a traditional smoke detector detects smoke and thus only triggers an alarm after a fire has started. It is desirable to minimise any delay in triggering a fire alarm to maximise the time for the occupants to evacuate, particularly for a large building with many occupants. Likewise, it is desirable to minimise false positives as these can be highly disruptive and costly. The present disclosure seeks to address these issues. 
     SUMMARY OF THE INVENTION 
     According to a first specific aspect, there is provided an electrical socket system comprising: 
     an electrical socket comprising at least one temperature sensor; and 
     a controller configured to monitor a temperature sensed by the temperature sensor. The controller may be configured to: 
     determine a temperature gradient of the temperature with respect to time; 
     determine if the temperature gradient exceeds a threshold gradient value; and 
     trigger an alarm event if it is determined that the temperature gradient exceeds the threshold gradient value. 
     The threshold gradient value may be variable. The threshold gradient value may have a default, e.g. initial, value, which may be varied. The default threshold gradient value may be varied after installation of the electrical socket, e.g. depending on at least one sensed parameter. 
     The controller may be configured to receive power usage data for the electrical socket. The controller may be configured to adjust the threshold gradient value for the electrical socket depending on the power usage data for the electrical socket. The controller may be configured to increase the threshold gradient value for the electrical socket if the electrical socket has a power usage that exceeds a threshold power value. The power usage data may comprise present and/or historical power usage data. The power usage data may relate to a particular electrical socket and the threshold gradient value may be adjusted for that particular electrical socket. 
     The controller may be configured to receive data relating to ambient conditions, such as temperature, pressure, humidity and/or any other ambient parameter. The ambient conditions may relate to atmospheric conditions for the electrical socket, which may be within a room or outside a building. The controller may be configured to adjust the threshold gradient value depending on the data relating to ambient conditions. 
     The controller may comprise a machine learning (or artificial intelligence) algorithm. The machine learning algorithm may be configured to adjust the threshold gradient value for the electrical socket (e.g. a particular electrical socket of a plurality of electrical sockets) based on at least one detected electrical power parameter of the electrical socket, data relating to ambient conditions and/or time of day. For example, the machine learning algorithm may use time of day data, e.g. to determine that power usage is typically high for a particular electrical socket at a particular time of day. The machine learning algorithm may adjust (e.g. increase) the threshold gradient value for the particular electrical socket at the particular time of day when power usage is known to be high. 
     The machine learning algorithm may be configured to minimise false determinations of an alarm event. The machine learning algorithm may receive data regarding false positives so that the machine learning algorithm may adjust the threshold gradient values to minimise false positives. 
     The electrical socket may be configured to measure at least one electrical power parameter. The at least one electrical power parameter may comprise at least one of electrical power, current, frequency and power factor. The threshold gradient value may vary depending on at least one of the electrical power parameters. 
     The electrical socket system may comprise a plurality of electrical sockets. The controller may monitor the temperature and temperature gradient of each electrical socket. The controller may determine if one of the electrical sockets has a temperature gradient that exceeds the threshold gradient value, e.g. for that particular electrical socket. The threshold gradient value may be different for different electrical sockets. 
     The electrical socket may comprise at least two temperature sensors. In particular, the electrical socket may comprise at least three temperature sensors. For example, the electrical socket may comprise four temperature sensors. Having multiple temperature sensors may provide some redundancy and/or verification of the sensed data. For example, having at least three temperature sensors may allow the system to identify a faulty temperature sensor. 
     The temperature sensors may be located at or near known arc points within the electrical socket. The temperature sensors may be mounted on a printed circuit board of the electrical socket. The temperature sensors may be distributed around the printed circuit board. The temperature sensors may be provided on one or both sides of the printed circuit board. 
     The electrical socket and controller may be coupled together. Alternatively, the controller may be separate from the electrical socket. 
     The electrical socket system may comprise a plurality of electrical sockets and each electrical socket may be operatively coupled to a hub. The electrical sockets may be coupled to the hub wirelessly (e.g. via Bluetooth, Wi-Fi, or any other wireless protocol) or via a wired connection (e.g. ethernet, powerline network or any other wired connection). The hub may comprise the controller. The hub may form part of or may be operatively coupled to a building management system. The building management system may comprise the controller. 
     The electrical socket may comprise at least one warning device configured to emit a warning sound and/or light when it is determined that the temperature gradient exceeds the threshold gradient value. A particular one of the electrical sockets (e.g. that has a temperature gradient that exceeds the threshold gradient value) may emit the warning or all electrical sockets (e.g. within a particular zone) may emit the warning. 
     According to a second specific aspect, there is provided a method for an electrical socket comprising at least one temperature sensor, the method comprising monitoring a temperature sensed by the temperature sensor. 
     The method may further comprise: 
     determining a temperature gradient of the temperature with respect to time; 
     determining if the temperature gradient exceeds a threshold gradient value; and 
     triggering an alarm event if it is determined that the temperature gradient exceeds the threshold gradient value. 
     The method may further comprise adjusting the threshold gradient value based on power usage data for the electrical socket. 
     The method may further comprise adjusting the threshold gradient value depending on data relating to ambient conditions. 
     The method may further comprise applying a machine learning algorithm to adjust the threshold gradient value for the electrical socket based on at least one detected electrical power parameter of the electrical socket and/or data relating to ambient conditions. 
     Other features descried in respect of the first specific aspect may apply to the second specific aspect. 
     These and other aspects will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments will now be described, by way of example only, with reference to the following drawings, in which: 
         FIG.  1    is a schematic block diagram depicting an electrical socket system according to an example of the present disclosure; 
         FIG.  2    is another schematic block diagram depicting an electrical socket system according to an example of the present disclosure; 
         FIG.  3    is a view of an electrical socket according to an example of the present disclosure; 
         FIGS.  4   a  and  4   b    collectively  FIG.  4   ) are front and back views respectively of a printed circuit board for an electrical socket according to an example of the present disclosure; 
         FIG.  5    is a graph depicting the variation of temperature (T) with time (t) according to an example of the present disclosure; and 
         FIG.  6    is a flowchart depicting a method according to an example of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     With reference to  FIGS.  1  to  4   , the present disclosure relates to an electrical socket system  10  comprising at least one electrical outlet or socket  20 . The electrical socket  20  may receive a standard plug of an electrical appliance. 
     As depicted in  FIG.  1   , a plurality of electrical sockets  20  may be provided. The or each of the electrical sockets  20  may be operatively coupled to a hub  30 . The hub  30  may collect data from and send data to the electrical socket(s)  20 . The hub  30  may thus provide an interface to the electrical socket(s) and may manage the flow of data. The electrical socket(s)  20  may be coupled to the hub  30  wirelessly (e.g. via Bluetooth, Wi-Fi, or any other wireless protocol) or via a wired connection (e.g. ethernet, powerline network or any other wired connection). 
     The hub  30  may form part of or may be operatively coupled to a building management system  40 . The building management system  40  may be connected to a cloud server  50 . For example, the hub  30  and building management system  40  may be connected to one another via the cloud server  50 . The building management system  40  may otherwise connected directly to the hub  30  or may comprise the hub  30 . Other devices, such as a mobile device  45  (e.g. a mobile phone, tablet or any other mobile device), may connect to the building management system  40 , e.g. via the cloud server  50 . The mobile device  45  may provide remote access to the building management system  40 , e.g. to provide or view building management data or instructions. Additionally or alternatively, as will be described below, the mobile device  45  may connect directly to the hub  30  or electrical socket  20 . 
     With reference to  FIG.  2   , the or each electrical socket  20  comprises at least one temperature sensor  22   a - 22   d  configured to detect a temperature of the electrical socket  20 . The temperature sensor(s)  22   a - 22   d  may comprise a thermistor. The electrical socket system  10  further comprises a controller  60  configured to monitor the temperature sensed by the temperature sensor  22   a - 22   d . The electrical socket  20  and controller  60  may be coupled together. For example, the electrical socket  20  and controller  60  may be provided as single unit. As such, each electrical socket  20  may have a dedicated controller  60 . Alternatively, the controller  60  may be separate from the electrical socket  20 . For example, the hub  30  or building management system  40  may comprise the controller  60 . As such, a single controller  60  may control a plurality of electrical sockets  20 . 
     Referring still to  FIG.  2   , the or each electrical socket  20  may comprise at least one warning device. In the example shown, the electrical socket  20  comprises a light emitting device  24 , such as an LED light, and/or a sound emitting device  26 , such as a buzzer. The controller  60  is operatively coupled to the light emitting device  24  and/or sound emitting device  26 . The controller  60  controls the light and/or sound emitting devices  24 ,  26  to emit a warning based on the temperature sensed by the temperature sensor  22   a - 22   d.    
     With reference to  FIGS.  2 ,  3  and  4   , the or each electrical socket  20  may comprise at least two temperature sensors  22   a - 22   d . In the particular example shown, the electrical socket  20  comprises four temperature sensors  22   a - 22   d . The temperature sensors  22   a - 22   d  may be mounted on a printed circuit board  28  of the electrical socket  20 . (The controller  60  may be provided on or may be operatively coupled to the printed circuit board  28 .) The temperature sensors  22   a - 22   d  may be distributed around the printed circuit board  28 , e.g. at or near points within the electrical socket  20  where electrical arcing may occur. The temperature sensors  22   a - 22   d  may be provided on one or both sides of the printed circuit board  28 . For example, first and second temperature sensors  22   a ,  22   b  may be provided on a first side of the printed circuit board and third and fourth temperature sensors  22   c ,  22   d  may be provided on a second side of the printed circuit board. 
     Having multiple temperature sensors  22   a - 22   d  may provide a degree of redundancy, e.g. in case one of the temperature sensors fails. Multiple temperature sensors  22   a - 22   d  may also allow electrical arcing in a particular region of the electrical socket  20  to be detected. Furthermore, the multiple temperature sensors  22   a - 22   d  may provide verification of the sensed data. For example, having at least three temperature sensors may allow the system to identify a faulty temperature sensor, which might otherwise have caused a false positive determination. 
     With reference to  FIG.  5   , the controller  60  is configured to determine a temperature gradient G of the temperature T with respect to time t. The controller  60  may take periodic temperature readings from the temperature sensors  22   a - 22   d  (e.g. at a frequency between 1 and 100 Hz) and may calculate the temperature gradient G with respect to time t. The controller  60  may comprise (or receive time data from) an electronic clock, which may be provided on or external to the controller, to assist in the calculation of the gradient. Alternatively, the controller  60  may obtain temperature data at a known frequency from which the time interval and thus gradient G can be deduced. The temperature gradient G may be calculated with reference to the temperature at a previous time, e.g. in a stepwise fashion, or by fitting a curve to the temperature values and estimating the temperature gradient. 
       FIG.  5    shows the variation of temperature T with time t for a number of scenarios A-E. Scenarios A-D depict normal functioning of the electrical socket  20  and as shown the temperature T initially rises and then levels off. The power usage in scenarios A-C may be higher than that in scenario D, which may cause the lower ultimate temperature in scenario D. In scenario E, there is a sharp spike in the temperature T, which may be caused by electrical arcing. In each case, the gradient G is determined and compared to the threshold gradient value. In the case of scenario E, the spike in temperature T may exceed the threshold gradient value. 
     The controller  60  may determine if the temperature gradient at a particular time exceeds a threshold gradient value. If the temperature gradient exceeds the threshold gradient value, the controller  60  may trigger an alarm event. The alarm event may comprise emitting a warning sound and/or light, e.g. via the light and/or sound emitting devices  24 ,  26  or any other warning device. The controller  60  may trigger the alarm event such that the warning devices of a particular one of the electrical sockets  20  (e.g. that has the temperature gradient G exceeding the threshold gradient value) may emit the warning. Alternatively, the controller  60  may trigger the alarm such that all electrical sockets  20  (e.g. within a building or a particular zone) may emit the warning. The building management system  40  may indicate to a user which of the electrical sockets  20  caused the alarm event. 
     The temperature within the electrical socket  20  is likely to quickly rise when an arcing event occurs. Thus, by monitoring the temperature gradient G and triggering an alarm event when the gradient exceeds the threshold value, the electrical socket system  10  can more quickly determine if an arcing event has occurred in the electrical socket  20 . 
     In an example in which the controller  60  is operatively coupled to more than one electrical socket  20 , the controller  60  may monitor the temperature and temperature gradient of each electrical socket  20 . The controller  60  may determine if one of the electrical sockets  20  has a temperature gradient that exceeds the threshold gradient value, e.g. for that particular electrical socket  20 . The threshold gradient value may be different for different electrical sockets  20 . 
     The threshold gradient value may have a default value. However, this may be subsequently varied. For example, the default threshold gradient value may be varied after installation of the electrical socket  20 , e.g. depending on at least one sensed environmental and/or electrical parameter. 
     In particular, the electrical socket  20  may be configured to measure at least one electrical power parameter. The controller  60  may be configured to receive data relating to the electrical power parameters. The at least one electrical power parameter may comprise at least one of electrical power, current, frequency and power factor. The threshold gradient value may vary depending on at least one of the electrical power parameters. For example, the controller  60  may be configured to increase the threshold gradient value for the electrical socket  20  if the electrical socket has a power usage that exceeds a threshold power value. Similarly, the controller  60  may be configured to decrease the threshold gradient value for the electrical socket  20  if the electrical socket has a power usage that is less than a threshold power value. 
     The power usage data may comprise present data that reflects the power usage at that moment in time. Additionally or alternatively, the power usage data may comprise historical power usage data and such historical data may be analysed and used to set an appropriate threshold gradient value. Furthermore, the power usage data may relate to a particular electrical socket  20  and the threshold gradient value may be set for that particular electrical socket. As such, each electrical socket  20  may have its own threshold gradient value. 
     In addition to or instead of the power usage data, the controller  60  may receive data relating to ambient atmospheric conditions, such as temperature, pressure, humidity and/or any other ambient parameter. The ambient conditions may relate to atmospheric conditions for the electrical socket, which may be within a room or outside a building. At least one ambient condition sensor may detect one or more of the ambient conditions and send the data to the controller  60 , e.g. via the hub  30 , cloud  50  and/or building management system  40 . The ambient condition sensor(s) may be provided on the electrical socket  20  or they may be separate from the electrical socket  20 . Alternatively, no ambient condition sensors may be provided and ambient condition data may be provided by an external source, such as an online weather data provider. The controller  60  may adjust the threshold gradient value depending on the ambient conditions data. For example, if the atmosphere has a high level of humidity, the threshold temperature gradient may be reduced. Electrical arcing may be more likely to occur in a humid atmosphere and it may be desirable to increase the sensitivity of the controller. 
     The controller  60  may comprise a machine learning (or artificial intelligence) algorithm. The machine learning algorithm may be configured to adjust the threshold gradient value for the electrical socket  20  (e.g. a particular electrical socket of a plurality of electrical sockets) based on at least one detected electrical power parameter of the electrical socket, data relating to ambient conditions and/or time of day. For example, the machine learning algorithm may use time of day data, e.g. to determine that power usage is typically high for a particular electrical socket  20  at a particular time of day. The machine learning algorithm may adjust (e.g. increase) the threshold gradient value for the particular electrical socket  20  at the particular time of day when power usage is known to be high. At other times, the threshold gradient value may be reduced. This may reduce the likelihood of false positive determinations, but maintain sensitivity at other times. 
     The machine learning algorithm may be configured to minimise false determinations of an alarm event. The machine learning algorithm may receive data regarding false positives so that the machine learning algorithm may adjust the threshold gradient values to minimise false positives. 
     With reference to  FIG.  6   , the present disclosure relates to a method  100  for the electrical socket  20 . The method comprises a first block  110  in which the temperature of the or each electrical socket  20  is monitored by the temperature sensor  22   a - 22   d . In a second block  120  the temperature gradient (dT/dt) of the temperature with respect to time is determined. In a third block  130  it is determined if the temperature gradient exceeds the threshold gradient value. In a fourth block  140 , an alarm event is triggered if it is determined that the temperature gradient exceeds the threshold gradient value. The alarm event may indicate that the electrical socket may be on fire. 
     The method  100  may further comprise a fifth block  150  in which a machine learning algorithm is applied. The machine learning algorithm may adjust the threshold gradient value for the electrical socket based on the time of day, at least one detected electrical power parameter of the electrical socket and/or data relating to ambient conditions. The machine learning algorithm may be applied if the determination in the fourth block  140  is negative, i.e. the temperature gradient is less than the threshold gradient value. 
     In a sixth block  160 , which may be carried out between the first and second blocks  110 ,  120 , the data from multiple temperature sensors  22   a - 22   d  of a particular electrical socket  20  may be compared to one another. If one or more of the temperature sensors  22   a - 22   d  disagrees with others of the temperature sensors, then a warning may be emitted in a seventh block  170 . The method  100  may otherwise continue, e.g. for other ones of the electrical sockets  20 . 
     In an eight block  180 , which may be carried out between the first and second blocks  110 ,  120 , the data from the temperature sensors  22   a - 22   d  of a particular electrical socket  20  may be compared to an absolute threshold temperature value, e.g. 150 degrees C. If the temperature exceeds this value, then the method may proceed to the fourth block  140  in which the alarm event is triggered. The method may otherwise proceed to the second block  120  in which the temperature gradient is calculated. 
     As mentioned above, the method  100  may further comprise adjusting the threshold gradient value based on power usage data for the electrical socket and/or data relating to ambient conditions. 
     The present disclosure may also relate to a method of commissioning the electrical socket system  10 . The electrical socket system  10  may be a new installation or electrical sockets  20  may be retrofitted into an existing electrical system. During commissioning, the mobile device  45  may communicate directly with the electrical socket  20  and/or hub  30 . For example, the mobile device  45  may wirelessly communicate with the electrical socket  20  and/or hub  30 , e.g. via Bluetooth. The electrical socket  20  and/or hub  30  may be configured to communicate with the mobile device  45  and receive data from the mobile device  45 . 
     The mobile device  45  may assist with the commissioning process. For example, the mobile device  45  may assist with pairing the hub  30  and electrical socket  20  to one another. The mobile device  45  may connect to the electrical socket  20 . A user may then select a particular hub  30  for the electrical socket  20  to pair with. The mobile device  45  may display a list of available hubs for the user to select. The electrical socket  20  and particular hub  30  may then be paired together, e.g. via the wired or wireless means mentioned above. 
     In addition, the mobile device  45  may connect to the electrical socket  20  and/or hub  30  to provide installation data to the electrical socket  20  and/or hub  30 . Such installation data may comprise the identity of the electrical socket  20 , a location of the electrical socket  20  (e.g. room, zone etc.), likely use of electrical socket  20  and/or any other pertinent data relating to the electrical socket  20 . The installation data may then be stored on the hub  30 , electrical socket  20 , cloud server  50 , BMS  40  and/or any other device. The electrical socket  20  may be identified with an identifier, such as a number, barcode, QR code or any other indicia. For example, the mobile device  45  may comprise a camera or other such scanning device to capture the identifier. The mobile device  45  may then send the identifier (along with any other installation data if provided) to the electrical socket  20  and/or hub  30 . The mobile device  45  may have an application (or “app”) stored thereon to provide the functionality described above. 
     Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the principles and techniques described herein, from a study of the drawings, the disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored or distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.