Appliances and Method of Determining Power Consumption Field of the Invention

The present invention relates to a power consumption measurement device, a system for providing information about the power consumption of a plurality of appliances and a method of determining power consumption. Background of the Invention

There is growing interest in smart measurement technology, particularly for the home environment, to identify and manage power consumption patterns, both from the point of view of consumers looking to reduce their energy bills, and from energy companies looking for ways to manage and predict overall energy demand. Smart measurement technology includes both smart meters that measure aggregated electricity

consumption and that automatically communicate that information to energy providers, and smart plugs which are inserted between an appliance and the power socket to measure consumption of individual appliances. To allow a central system, such as a client computer or smart meter, to process, analyse and present useful information based on power consumption information, the smart device from which the information originates should have some way of identifying the appliance to which it is connected. GB2492482 discloses a smart plug type device that includes a photonic identifier arrangement for identifying an appliance, such as a washing machine, that is plugged into the device. By knowing the identity of the appliance, measured power

consumption information can be associated with the specific appliance and transmitted to a user interface for further processing.

Although smart plug devices as described above can associate appliance identification information with power consumption information, this relies on the appliance being correctly identified. For example, the system of GB2492482 discloses the use of a label on the appliance plug to identify the appliance, the label having a pattern of reflective or absorbing portions. Four dots will allow the identification of up to 16 devices, while five dots will allow up to 32 devices. However, if the label were to become detached from the plug, and be incorrectly attached to the wrong appliance, or the system is otherwise tampered with, for example by a consumer splicing two cables together instead of changing the plug, the identification system could break down.

Summary of the Invention

According to an aspect of the invention, there is provided a power consumption measurement device comprising a socket for receiving an electrical plug connected to an appliance, a data collection circuit arranged to determine information relating to power consumption of the appliance, an information transmitter arranged to transmit the information relating to the power consumption, a first identification module arranged to determine first identity information for the appliance that is plugged into the device, and a second identification module arranged to determine second identity information for the appliance that is plugged into the device.

Obtaining first and second identity information permits cross-checking of the identity of the appliance, so that the risk of incorrect appliance information being provided may be decreased. The second identification module may be arranged to verify the identity of the appliance determined by the first identification module.

Once an appliance is reliably identified, the user can then safely and confidently control the appliance remotely, as well as being able to use a user interface to safely and confidently perform multiple actions for multiple appliances.

The device may comprise a memory for storing the first identity information and the second identity information. The first identification module may comprise a detector arranged at the socket for determining a pattern arranged on a surface of the appliance plug. The pattern may be on a label attached to the surface of the appliance plug. The pattern maybe a pattern of black and white dots readable by the detector, or may comprise barcode or matrix code information. The first identification module may comprise a plurality of light emitting devices arranged to transmit light via the socket face towards the appliance plug and means for receiving a corresponding signal reflected from the appliance plug. The light may comprise infra-red light.

The device may further comprise a pipe having an outlet at the socket face, a first branch of the pipe extending to at least one of the light emitting devices, the pipe further comprising a second branch extending to a detector for detecting the reflected light.

The second identification module may be arranged to identify a power characteristic associated with use of the appliance, wherein the power characteristic may be electromagnetic interference EMI generated by or associated with operation of the appliance.

The device may further comprise a processor for comparing a currently determined characteristic with a previously stored characteristic. The processor may be arranged to generate an alert if the currently determined characteristic is not the same as the previously stored characteristic. The alert can be a visual or audible alert or result in some other action in the system, such as a message being sent or an appliance being temporarily disabled.

The processor may be arranged to generate a verification signal if the currently determined characteristic is the same as the previously stored characteristic.

When the first identity information is the same as previously stored first identity information, the processor is arranged to determine whether the second identity information is the same as previously stored second identity information. Where the first identity information is different, it may be assumed that a different appliance has been plugged in, so that new second identity profiles should be stored.

If the first identity information is the same as the previously stored first identity information, and the second identity information is the same as the previously stored second identity information, the processor may be arranged to provide a verification signal, while if the second identity information is not the same as the previously stored second identity information, the processor may be arranged to provide an alert signal. The information transmitter may be arranged to transmit the first identity information and optionally the second identity information together with the power consumption information, for example to a central communications hub.

According to a further aspect of the invention there is provided a power consumption measurement device comprising a socket for receiving an electrical plug connected to an appliance, means for determining information relating to power consumption of the appliance, means for transmitting the information relating to the power consumption, first identification means for determining first identity information for the appliance that is plugged into the device and second identification means for determining second identity information for the appliance that is plugged into the device.

The second identification means may comprise means for verifying the first identity information.

The device may be a smart plug, a smart socket or an extension socket, any of which may be generically referred to as a smart device. According to a yet further aspect of the invention, there is provided a system for providing information about power consumption of a plurality of appliances, the system comprising a plurality of power consumption measuring devices, each comprising a socket for receiving an electrical plug connected to an appliance, a data collection circuit arranged to determine information relating to power consumption of the appliance, an information transmitter arranged to transmit the information relating to the power consumption, a first identification module arranged to determine first identity information for the appliance that is plugged into the device, and a second identification module arranged to determine second identity information for the appliance that is plugged into the device, the system further comprising a

communications module for receiving the power consumption information from each of the plurality of power consumption measuring devices.

The communications module may be arranged to transmit the information over the Internet to a computer server, for example for further analysis or presentation on a website. The computer server may be arranged to determine the identity of each appliance from the first identity information. The computer server may be arranged to verify the first identity information using the second identity information. The first identity information may be derived from the pattern associated with the plug of the appliance. The pattern may be arranged on a label affixed to the plug.

The second identity information may comprise an EMI profile determined during use of the appliance.

According to a still further aspect of the invention, there is provided a power consumption measurement device comprising a socket for receiving an electrical plug connected to an appliance, a processor arranged to collect information relating to power consumption of the appliance, an information transmitter arranged to transmit the information relating to the power consumption, an identification module arranged to determine the identity of the appliance that is plugged into the device and a verification module arranged to verify the identity of the appliance determined by the identification module. According to yet another aspect of the invention, there is provided a method of determining power consumption of an appliance plugged into a power consumption measurement device, the device comprising a socket for receiving an electrical plug connected to the appliance, a processor arranged to collect information relating to power consumption of the appliance, an information transmitter arranged to transmit the information relating to the power consumption, a first identification module arranged to determine first identity information of the appliance that is plugged into the device, and a second identification module arranged to determine second identity information of the appliance that is plugged into the device, the method comprising using the first identification module to distinguish between different types of appliance plugged into the device and using the second identification module to distinguish between different appliances of the same type.

For example, the first identification module may distinguish between a washing machine and a refrigerator, while the second identification module may distinguish between different models of washing machine. Brief Description of the Drawings

Exemplary embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure l is an overview of a system according to an embodiment of the invention.

Figure 2A illustrates an example of a power consumption measurement device that forms part of the system of Figure l.

Figure 2B illustrates another example of a power consumption measurement device that forms part of the system of Figure l.

Figure 3 is a system diagram of the power consumption measurement device of Figure 2A.

Figure 4 is an example of a sensor device pattern on the face of the socket of the power consumption measurement device according to an embodiment of the invention.

Figure 5 is an example implementation of a sensor device as shown in Figure 4.

Figure 6 is a diagram illustrating a plug label according to an embodiment of the invention.

Figures 7A and 7B are diagrams showing plug labels illustrating various pattern of dots that can be read by the sensor device pattern shown in Figure 4.

Figure 8 is a flow chart explaining the operation of the system according to

embodiments of the invention.

Detailed Description

Figure 1 is an overview of a system according to an embodiment of the invention.

Figure 2A illustrates an example of a power consumption measurement device that forms part of the system of Figure 1, where the device is a plug for being plugged into a socket and for in turn receiving an appliance plug. This type of device is alternatively referred to as a smart plug. Figure 2B illustrates another example of a power consumption measurement device that forms part of the system of Figure 1. In this case the device is a socket for receiving an appliance plug, as might conventionally be mounted in the wall of a house. This type of device is alternatively referred to as a smart socket.

While smart plugs and smart sockets are specifically illustrated, it is contemplated that the power consumption measurement device may be implemented in any form that allows an appliance to be plugged in, for example as an extension socket, also referred to as a plug board or multi-socket adaptor. In general terms, the system will be described by reference to a smart plug, but it will be understood that this is not limiting.

Referring to Figure l, a system l according to an embodiment of the invention comprises one or more power consumption measurement devices, for example, smart plugs 2. A plurality of smart plugs 2a, 2b, 2n are shown, each of the plugs being connected to the household electricity supply (mains) 3. In one embodiment, data from each of the smart plugs is transmitted externally over the mains using a power line communication (PLC) scheme. A PLC to Ethernet bridge 4 is also connected to the household electricity supply to allow connection to a network such as, but not limited to, the Internet 5 via, for example, an RJ45 socket. The PLC to Ethernet bridge converts data bidirectionally between the internet and the PLC system, so that the smart plugs can be controlled via the Internet. The data measured by the smart plugs is sent to a computer system 6 where it is processed and can subsequently be accessed by the consumer over the Internet, for example showing the actual cost in monetary terms, rather than just power units (e.g. kWh), of running each appliance within the home.

Each consumer may have an account on the computer system 6 which holds

information such as the consumer's current energy tariff, to allow the calculation of the monetary cost of each appliance.

Figure 2A shows one example of a smart plug according to an embodiment of the invention. Referring to Figure 2A, the smart plug 2 includes a socket 10 for receiving an appliance plug (not shown), status indicators 12, for example power on and error indicators, a plug 13 for plugging the smart plug into a conventional power socket (not shown), a sensor arrangement 14 for use in appliance identification and optionally a USB socket or other form of interface 15 for receiving and powering external sensors and devices. The device plug and power socket are conventional devices, for example a 3-pin plug and corresponding socket in the UK, but the appropriate plug and socket arrangement adapted to the requirements of each country of use would be used in practice.

Figure 2B shows an example of a smart socket 7. This includes a socket face 10 and a sensor arrangement 14 as described above in relation to the smart plug. Figure 3 illustrates the internal structure of the smart plug 2 shown in Figure 2A. The smart plug comprises a data measurement/collection circuit 16 for determining the voltages and current necessary to calculate power consumption of the attached appliance, a data transmission circuit 17 for transmitting information via the mains or, optionally, wirelessly, memory 18, for example flash memory, a microprocessor 19, an optional USB interface 20 and an API 21 running under the control of the

microprocessor 19 to allow external access to the smart plug functionality. The smart plug 2 further includes a sensor interface module 22 connected to the sensor arrangement 14 on the face of the plug and an electromagnetic interference (EMI) module 23. Both the sensor interface module and the EMI module interface with the microprocessor 19.

It will be understood that the circuit arrangement within the smart socket 7 or extension socket (not shown) is essentially identical to that within the smart plug, other than that the plug 13 is replaced by the appropriate connector arrangement to allow the socket to be connected to the electricity supply.

The sensor interface module 22 will be described in more detail below. The EMI module 23 comprises an EMI sensor 24, alternatively referred to as an EMI detector circuit 24, and an analogue to digital converter (ADC) 25. The EMI detector circuit 24, also referred to as an electromagnetic field (EMF) detector, is arranged to detect electromagnetic interference EMI generated by or associated with the appliance that is plugged into the smart plug. Each appliance will generate its own pattern of EMI that depends on its electrical construction and operation. The EMI detector detects, for example, the EMI noise that is conducted by the power lines at the smart plug and in addition may measure the EMI that is locally radiated by the appliance. The detected analogue EMI field is converted into a digital signal by the analogue to digital converter (ADC) 25 before being supplied to the microprocessor 19. It will be apparent to the skilled person that the EMI detector may be integrally provided with the ADC circuit, so providing an EMI module 23 that outputs a digital signal, representative of the EMI field, which can be read by the microprocessor 19.

The EMI field pattern can be analysed at sufficiently high sampling rates to provide high levels of data granularity, so allowing unique EMI digital profiles to be produced for each appliance. When an electrical appliance is plugged into the smart plug, data on power

consumption is collected, stored in flash memory and transmitted via the electrical wiring system (mains) within the house to the bridge plug 4 which transmits the data over the internet to a server, where the data is processed and can subsequently be accessed by the consumer. In addition to transmission via the house's electrical system, the data can also be transmitted via a wireless network with wireless transmitter/receivers built into each smart plug. As mentioned above, any substantive analysis of power usage by an appliance requires that the smart plug and ultimately the central server is aware of the identity of the appliance. Without this information, patterns of power usage at different times cannot be determined, particularly since a consumer may unplug one appliance from a smart plug and plug in another.

However, once power consumption information with reliable appliance identification information is transmitted to a central control system, sophisticated power

management strategies can be applied. For example, where the appliance is identified as a refrigerator, the central control system is aware that power to the device cannot be disconnected. But where the device is a washing machine, the central system may be able to recommend, or even control, the turn-on of the machine to be delayed until a more favourable energy tariff is available.

Figure 4 illustrates in more detail the sensor array 14 on the face of the device socket 10. Figure 5 shows an example implementation of one sensor 26 in the sensor array.

Each sensor 26 comprises a light guide 27, for example, made of glass or plastic, comprising a single pipe section 27a passing through the socket face 28, the single pipe section being connected to first and second branches 27b, 27c. An infra red light emitter 29 is arranged at the end of the first branch 27b and a photodetector 30 arranged at the end of the second branch 27c. Light passes from the emitter 29 through the socket face 28 and is reflected from the plug face 31, the reflected light being detected by the photodetector 30. The infra-red light emitter 29 is arranged to emit a continuous series of pulses under the control of a control circuit 32 towards the appliance plug plugged into the socket. The light is absorbed by or reflected from a corresponding region 33 on the plug surface and the reflected signal is detected by the photodetector.

Figure 6 illustrates a label 35 to be applied to the surface of the plug, the label including a predetermined pattern to identify a particular appliance. The label may be made of paper, plastic or any suitable material that allows the application of a pattern.

Figure 6 shows four possible dot positions 36 at which a reflective or absorbing portion may be placed to indicate the presence or absence of a dot in that region. For example, where a reflective portion is attached at the dot position, the infra red light is reflected more strongly from that dot position than from the surrounding area, which indicates the presence of a dot. Alternatively, a black portion or dot could be placed in the region which absorbs infra red light provided by the sensor. In this case, the absence of a strong reflection indicates the presence of a dot in that region.

By combining a plurality of dots a number of different appliances can be identified in accordance with a standard binary code. For example, by providing four regions which may or may not contain a dot, sixteen different appliances can theoretically be identified ranging from the absence of all dots (binary o) to the presence of four dots (binary 15). In practice, a smaller number of appliances may be identifiable since it may be desirable to exclude the presence of all dots or no dots to differentiate from a plug that does not include a label according to the invention.

While the above embodiment has been described with four dots, the number of dots is of course not limited and, for example, five dots would enable the identification of up to thirty-two (practically, 30) appliances.

As an example, Figure 7A illustrates a label for a microwave having, for example, two dots 37 disposed diagonally, while Figure 7B illustrates a label for a washing machine having two dots 38 disposed in an alternative diagonal configuration. Figure 7A represents, for example, appliance ID 5 (binary code 0101), starting from the top left and working clockwise, while Figure 7B represents appliance ID 10 (binary code 1010). However, the appliance IDs are clearly not limited to these specific codes.

While the above examples have been described using black/white dots, the number of devices that can be identified may be increased, for example by using a miniature barcode or matrix code (such as a QR code) instead of just a dot. Using 2 bar/matrix codes on a smart plug would give the ability to uniquely identify a very large number of devices. Figure 8 is a flowchart illustrating the operation of the system according to

embodiments of the present invention. It is assumed that a label for each of the appliances in a home has been located over the pins of each appliance plug by a system installer, and that the system has been appropriately commissioned. The process of identifying each appliance is described in detail below.

First, the photonic module 14, 22 (comprising the sensor arrangement 14 and the sensor interface 22) is used to determine first identity information for the appliance, for example an appliance identifier ID, and to store this information in the memory 18, under the control of the microprocessor 19 (step si). This step can be carried out while the power to the appliance is switched on, but before the appliance is operational. Then, once the appliance is operating, the EMI module 23 (comprising the EMI sensor), is used to determine second identity information for the appliance, for example the EMI profile of the appliance, and to store this information in the memory 18 against the appliance ID (step S2).

The processor 19 in the smart plug then compares the appliance ID against a previously stored appliance ID to determine whether the appliance has changed (step S3). If the appliance IDs are the same (step S3), then the processor 19 determines whether the second identity information is the same as the previously stored second identity information (step S4). For example, the processor 19 compares the EMI profile of the appliance with a previously stored EMI profile to determine whether the profiles are similar enough to be considered to originate from the same appliance. In other words, two profiles are considered to be the same if the differences between them fall within a predetermined threshold.

If the EMI profile of the current appliance is the same as the stored profile, then the device identity is verified, so that power consumption data can be measured and transmitted to the bridge plug 4 together with the first identity information and, optionally, the second identity information (step S5). If a comparison of the EMI profiles indicates that the profiles are not the same (step S4), indicating that the profiles originate from different appliances, an alert is raised, for example by a flashing or constant red status light at the smart plug (step s6). This indicates that even though the appliance identifiers, comprising the first identification information, are apparently the same, the appliance itself is not the original, or is defective in some way.

If it is found when comparing the appliance IDs that these are not the same (step S3), then the consumer can be asked to confirm that the appliance has been changed (step S7) and following such confirmation, the smart plug can again proceed to transmit power consumption data to the bridge plug 4 (step S5).

The data transmitted from each smart plug is ultimately received by the computer system 6 via the bridge plug 4 and processed and stored against the appliance ID (step s8).

Should the consumer unplug one appliance from the smart plug and connect another, the appliance ID changes and the stored data is then associated with the different ID. This permits long term analysis of data for each different appliance. When a new appliance is plugged in to a smart plug for the first time, the second identity

information is stored against that appliance ID for the first time and subsequently becomes the previously stored data against which use of the appliance is compared.

Alternatively, the system can permit only certain types of appliances with

predetermined EMI profiles to be connected, so that if a new appliance is plugged in which is not permitted, power consumption information for that appliance will not be provided.

While it has been described that the verification process is carried out at the smart plug, the process need not be carried out at the smart plug but could be carried out at the central server or at an intermediate location such as the bridge plug 4.

It will be appreciated that an appliance is likely to have a varying EMI profile across its operating range. For example, a washing machine will have distinct EMI profiles while it is filling with water, while the motor rotates the tub during washing, during the spin cycle, during draining and so on. A plurality of individual profiles can therefore be stored and compared to improve the device identification process.

It will be further appreciated that the principles disclosed in this application permit appliance identification, authentication and control to be processed within the smart device itself, managed from the cloud and instigated by a remote user interface, or automated system, ultimately allowing the appliances to be available for monitoring and control as part of the 'internet of things'. In summary, in embodiments of the invention, two signals are provided by the smart device for the purpose of identification and verification, the first being an identification signal, for example a photonic signal based on, for example, infra-red sensors, and the second being a verification signal based on, for example, an EMI profile. The identification signal provides the identity of the appliance plugged into the smart device, while the verification signal verifies that the identity is correct. In effect, the result is to authenticate the identity of the appliance, for example for the purpose of security.

Although the invention has been described by reference to specific embodiments, it would be apparent to the skilled person that these embodiments are not limiting and that various modifications and alternative arrangements are possible while still falling within the scope of the invention as defined in the accompanying claims and their equivalents.