GB2489517A

GB2489517A - Current sensor with switching device for energy storage and method for controlling appliances connected to a grid

Info

Publication number: GB2489517A
Application number: GB1105521.7A
Authority: GB
Inventors: Mark Adrian Habgood; Edward William Mellor
Original assignee: SEAMLESS SENSING Ltd
Current assignee: SEAMLESS SENSING Ltd
Priority date: 2011-03-31
Filing date: 2011-03-31
Publication date: 2012-10-03
Also published as: GB201105521D0

Abstract

A current measurement device comprises a current transformer 12 and a switch 16 that switches the output of the current sensor to either an energy storage device 18 such as a capacitor or to a current measurement circuit 20. When a measurement is not being made, the switch charges the capacitor to store energy to power the measurement circuit. The measurement circuit may include a wireless transmitter 22 and the current transformer may be of the type that clamps around a cable 32. In another aspect (figures 3 and 4 â not shown), the current sensor may be used in part of a monitoring system that measures energy consumption of appliances connected to a grid. If the appliance energy consumption is above a threshold then a control signal may switch off the appliance or alert the user. The monitoring system may be used to select the best tariff for a consumer.

Description

TITLE

Apparatus for monitoring electrical current and Systems for electrical energy management

TECHNOLOGICAL FIELD

Embodiments of the present invention relate to apparatus for monitoring electrical current. In particular, they relate to apparatus for monitoring electrical current in a system for electrical energy management.

BACKGROUND

Buildings, such as domestic housing, offices, restaurants and factories may be connected to an electrical grid for receiving electrical energy. Electrical energy may be distributed in a building to a variety of appliances such as lighting systems, heating systems, computers, ovens, washing machines, dishwashers, televisions and to plug sockets. The use of electrical energy by appliances has an associated financial cost and a person responsible for the payment of the electricity bill may struggle to maintain control of the buildings electrical energy usage.

Therefore, it would be desirable to provide apparatus for monitoring electrical current and a system for electrical energy management.

* BRIEF SUMMARY

* * **.* * S 5555. . . . . According to various, but not necessarily all, embodiments of the invention there is provided an apparatus for monitoring electrical current, the apparatus comprising: a current transformer for monitoring electrical current and 555 55.

* providing a signal; and switching circuitry for receiving the signal from the current transformer and having a first electrical configuration in which the signal is provided to an energy storage device, and a second electrical configuration in which the signal is provided to measurement circuitry.

The apparatus may further comprise the energy storage device, wherein the energy storage device includes one or more capacitors for storing electrical energy in the signal and for providing the stored electrical energy to at least the measurement circuitry.

The apparatus may further comprise the measurement circuitry, the measurement circuitry including a processor for controlling the switching of the switching circuitry and for determining the monitored electrical current from the signal.

The apparatus may further comprise a wireless transmitter for transmitting the 1 5 determined monitored electrical current.

The current transformer may be configured to form a clamp with at least a portion of the apparatus for clamping a cable for monitoring electrical current in the cable.

According to various, but not necessarily all, embodiments of the invention there is provided a module comprising an apparatus as described in any of the preceding paragraphs.

According to various, but not necessarily all, embodiments of the invention :°j there is provided an energy management system comprising one or more apparatus as described in any of the preceding paragraphs. S. S.

I *s

According to various, but not necessarily all, embodiments of the invention there is provided a method for monitoring current, the method comprising: controlling switching circuitry to switch between a first electrical configuration in which a signal from a current transformer is provided to an energy storage device, and a second electrical configuration in which the signal is provided to measurement circuitry.

The method may further comprise determining a voltage value of the signal, controlling the storage of the voltage value and determining a monitored electrical current value of the signal from the stored voltage value.

The method may further comprise controlling a wireless transmitter to transmit the determined electrical current value.

According to various, but not necessarily all, embodiments of the invention there is provided a computer program that, when executed by a processor, executes a method as described in any of the preceding paragraphs.

1 5 According to various, but not necessarily all, embodiments of the invention there is provided a computer-readable storage medium encoded with instructions that, when executed by a processor, perform a method as described in any of the preceding paragraphs.

According to various, but not necessarily all, embodiments of the invention there is provided a method for electrical energy management, the method comprising: receiving an electrical parameter value for one or more appliances; determining if the electrical parameter value for an appliance of the one or more appliances is greater than a predetermined electrical parameter value; and providing a control signal to the appliance to perform a first action if the determined electrical parameter value for the appliance is greater than the predetermined electrical parameter value. t

The first action may be providing an alarm to a user.

The first action may be powering off of the appliance. * .4

The electrical parameter value may be an electrical current value, and the predetermined electrical parameter value may be a predetermined electrical current value.

The method may further comprise providing a questionnaire to a user input device for enabling a user to identify the one or more appliances; receiving the completed questionnaire from the user input device; and providing the completed questionnaire to a tariff server for determining an energy tariff.

The method may further comprise receiving information indicating a change of electrical energy price and changing the predetermined electrical energy value using the received information.

The method may further comprise receiving information indicating the state of 1 5 an electrical energy grid; and providing a control signal to the one or more appliances to control the power level of the one or more appliances for balancing electrical energy demand with electrical energy production.

According to various, but not necessarily all, embodiments of the invention there is provided an apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform a method as described in any of the preceding paragraphs. *0*

According to various, but not necessarily all, embodiments of the invention there is provided a system for electrical energy management comprising an apparatus as described in the preceding paragraphs and one or more apparatus as described in any of the previous paragraphs. * 30 * S..

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According to various, but not necessarily all, embodiments of the invention there is provided a computer-readable storage medium encoded with instructions that, when executed by a processor, perform a method as described in any of the preceding paragraphs.

BRIEF DESCRIPTION

For a better understanding of various examples of embodiments of the present invention reference will now be made by way of example only to the accompanying drawings in which: Fig. 1 illustrates a schematic diagram of an apparatus according to various embodiments of the invention; Fig. 2 illustrates a flow diagram of a method of operation for the apparatus illustrated in fig.1 according to various embodiments of the invention; Fig. 3 illustrates a schematic diagram of a system for electrical energy management according to various embodiments of the invention; and Fig. 4 illustrates a flow diagram of a method of operation for the system illustrated in fig. 3 according to various embodiments of the invention. Sn.

DETAILED DESCRIPTION

In the following description, the wording connect' and couple' and their * derivatives mean operationally connected or coupled. It should be S..

appreciated that any number or combination of intervening components can exist (including no intervening components). Additionally, it should be appreciated that the connection or coupling may be a physical galvanic connection and/or an electromagnetic connection.

Figure 1 illustrates an apparatus 10 for monitoring electrical current, the apparatus 10 comprising: a current transformer 12 for monitoring electrical current and providing a signal: and switching circuitry 16 for receiving the signal from the current transformer 12 and having a first electrical configuration in which the signal is provided to an energy storage device 18, and a second electrical configuration in which the signal is provided to measurement circuitry 20.

In more detail, figure 1 illustrates an apparatus 10 for monitoring electrical current according to various embodiments of the invention. The apparatus 10 1 5 includes a current transformer 12, a voltage rectifier 14, switching circuitry 16, an energy storage device 18, measurement circuitry 20, a transmitter 22, and an antenna 24. The measurement circuitry 20 includes a shunt resistor 26, a processor 28 and a memory 30.

The apparatus 10 may be hand portable and may thus be installed on an alternating current (AC) electricity cable 32 by one person. In various embodiments, the current transformer 12 is configured to form a clamp with at least a portion of the apparatus 10 for clamping the cable 32. For example, the current transformer 12 may be supplied as a separate component to the remainder of the apparatus 10 and may define a cavity for receiving the cable 32 therein. During installation, a person may insert the cable 32 into the cavity of the current transformer 12 and then couple the current transformer 12 to the remainder of the apparatus 10 to clamp the apparatus 10 around the cable 32.

In some embodiments, the apparatus 10 may be a module. As used here, S..

module' refers to a unit or apparatus that excludes certain parts/components that would be added by an end manufacturer or a user. For example, the apparatus 10 may be a module that only includes the current transformer 12 and the switching circuitry 16 which may be connected to the other components mentioned above by an end manufacturer.

The current transformer 12 includes a coil of wire and one or more ports for connection to the voltage rectifier 14. The current transformer 12 may be positioned adjacent the AC cable 32 and is configured to generate an electrical signal via induction from the primary alternating current in the cable 32. It should be appreciated that the generated electrical signal is proportional to the primary current in the cable 32.

The voltage rectifier 14 may be any suitable voltage rectifier that is configured to receive the signal from the current transformer 12 and convert the signal from alternating current (AC) to direct current (DC). The voltage rectifier 14 may be an ultra low voltage drop rectifier and may be a solid state rectifier such as a silicon diode or a germanium diode for example.

The switching circuitry 16 is configured to receive the signal from the voltage rectifier 14 and has a first electrical configuration in which the signal is provided to the energy storage device 18, and a second electrical configuration in which the signal is provided to measurement circuitry 20. The switching circuitry 16 may include any suitable switching circuitry and may include ultra low power switching circuitry such as a field effect transistor : 25 (FET)forexample.

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S. .** * The energy storage device 18 is configured to receive the signal from the switching circuitry 16 (when the switching circuitry 16 is in the first electrical configuration) and store the electrical energy of the signal. The energy storage device 18 may include one or more capacitors, for example, that store S...

electrical energ9 received from the switching circuitry 16. The energy storage * ** device 18 is also configured to provide electrical energy to the other components of the apparatus 10 to enable them to operate. For example, the energy storage device 18 is configured to provide electrical energy to the processor 28 and to the transmitter 22 to enable them to operate as described below.

The shunt resistor 26 is configured to receive the signal from the switching circuitry 16 (when the switching circuitry 16 is in the second electrical configuration). The shunt resistor 26 may have any suitable resistance for enabling the measurement circuitry 20 to read the voltage across the shunt resistor 26.

The processor 28 is configured to read the voltage across the shunt resistor 26 (via an analog to digital converter), determine the electrical current of the monitored signal from the read voltage, and provide the determined electrical current value to the transmitter 22 for transmission. In various embodiments, the processor 28 is configured to read the voltage across the shunt resistor 26, store the peak voltage in the memory 30 and then determine the current of the signal using the stored peak voltage using a pre-calibrated look up table or transfer function stored in the memory 30. The processor 28 is also configured to provide a control signal to the switching circuitry 16 to control the electrical configuration of the switching circuitry 16 (i.e. to switch between the first and second electrical configuration).

The implementation of the processor 28 can be in hardware alone (a circuit for example), have certain aspects in software including firmware alone or can be a combination of hardware and software (including firmware). The processor 28 may be implemented using instructions that enable hardware

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functionality, for example, by using executable computer program instructions in a general-purpose or special-purpose processor that may be stored on a computer readable storage medium (disk, memory etc) to be executed by the * I..

processor 28. *si

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The processor 28 is configured to read from and write to the memory 30. The memory 30 may be any suitable memory and may be solid state memory such as flash memory. The processor 28 may also comprise an output interface via which data and/or commands are output by the processor 28 and an input interface via which data and/or commands are input to the processor 28.

The memory 30 stores a computer program 34 comprising computer program instructions that control the operation of the apparatus 10 when loaded into the processor 28. The computer program instructions 34 provide the logic and routines that enables the apparatus 10 to perform the method illustrated in Fig. 2. The processor 28 by reading the memory 30 is able to load and execute the computer program 34.

The computer program may arrive at the apparatus 10 via any suitable delivery mechanism. The delivery mechanism may be, for example, a computer-readable storage medium, a computer program product, a memory device, a record medium such as a USB flash memory, an article of manufacture that tangibly embodies the computer program 34. The delivery mechanism may be a signal configured to reliably transfer the computer program 34.

Although the memory 30 is illustrated as a single component it may be implemented as one or more separate components some or all of which may : 25 be integrated/removable and/or may provide permanent/semi-permanent/ dynamic/cached storage. ** .*

: The transmitter 22 is configured to receive the signal including the determined current value from the processor 28, encode the signal and then provide the encoded signal to the antenna 24 for transmission. For example, the I S Sees transmitter 22 may encode the signal according to the General Packet Radio 5*5 Service (GPRS) protocol for transmission.

The antenna 24 may be any suitable antenna for transmitting the signal and may be, for example, a loop antenna, a monopole antenna, a whip antenna, a planar inverted F antenna (PIFA), a planar inverted L antenna (PILA), an inverted F antenna (IFA) or an inverted L antenna (ILA).

The operation of the apparatus 10, when coupled to a cable conducting an alternating current, is described in the following paragraphs with reference to figs. 1 and 2.

At block 36, the processor 28 initialises the hardware of the apparatus 10 and controls the switching circuitry 16 to switch to the first electrical configuration.

At block 38, the processor 28 waits a period of time in order to charge the energy storage device 18.

At block 40, the processor 28 controls the switching circuitry 16 to switch to the second electrical configuration and thereby provide the signal to the shunt resistor 26.

At block 42, the processor 28 reads the voltage across the shunt resistor 26 and stores the peak voltage in the memory 30. For example, the processor 28 may read the voltage for one or two AC cycles (one cycle is 10 ms for a 50 Hz signal) and then store the peak voltage. * 25 S....

At block 44, the processor 28 controls the switching circuitry 16 to switch to the first electrical configuration and thereby maximise the electrical energy : stored in the energy storage device 18 for powering the transmitter 22.

At block 46, the processor 28 determines the monitored primary electrical S...

current value from the stored peak voltage value. For example, the processor 28 may use a pre-calibrated lookup table or transfer function to convert the peak voltage into a primary current value. In some embodiments, the processor 28 may determine a plurality of primary current values for a period time and then integrate them to determine the energy used over that time period.

At block 48, the processor 28 provides the determined current value to the transmitter 22 for transmission. The transmitter 22 may then transmit the determined current value to a management, logging, alarm device via the antenna 24. The method may then return to block 38 and be repeated.

Embodiments of the present invention may provide several advantages. One such advantage is that the apparatus 10 may require little or no maintenance once installed in an energy management system. This is because the energy storage device 18 may be charged by the output from the current transformer 1 5 12 and consequently, the apparatus 10 does not require the energy storage device 18 to be replaced after it has been depleted by the components of the apparatus 10.

Another advantage is that since the apparatus 10 includes a wireless transmission module (i.e. the transmitter 22 and the antenna 24) and is able to communicate information wirelessly, the apparatus 10 may be relatively simple to install and may not require a person who is skilled at laying wired communication lines.

A further advantage is that since the apparatus 10 is configured to clamp around an AC cable, it may be relatively simple to install the apparatus 10 on an AC cable. S... I..

Fig. 3 illustrates a schematic diagram of a system 100 for electrical energy management according to various embodiments of the invention. The system * S..

includes an apparatus 102 (which may also be referred to as an Appliance Fingerprinting Server'), a communication device 104, a current transformer 106, one or more smart plugs 108, one or more smart appliances 110, one or more user input devices 112, a tariff server 114, a grid fingerprinting server 116, a communication device 118, a grid monitor 120 and a power station/sub-station 122. The above components of the system 100 may communicate with one another via a wired and/or a wireless link. The apparatus 102 may also communicate with a home area network, a building management system, a local energy storage device such as an electric battery and a plurality of electric vehicles.

The apparatus 102 includes a processor 124, a memory 126 and a communication module 128. The implementation of the processor 124 can be in hardware alone (a circuit for example), have certain aspects in software including firmware alone or can be a combination of hardware and software (including firmware). The processor 124 may be implemented using 1 5 instructions that enable hardware functionality, for example, by using executable computer program instructions in a general-purpose or special-purpose processor that may be stored on a computer readable storage medium (disk, memory etc) to be executed by the processor 124.

The processor 124 is configured to read from and write to the memory 126.

The memory 126 may be any suitable memory and may be solid state memory such as flash memory, or may be one or more hard disk drives. The processor 124 may also comprise an output interface via which data and/or commands are output by the processor 124 and an input interface via which *...: 25 data and/or commands are input to the processor 124.

* The memory 126 stores a computer program 130 comprising computer program instructions that control the operation of the apparatus 102 when loaded into the processor 124. The computer program instructions 130 provide the logic and routines that enables the apparatus 102 to perform the ** *s..

method illustrated in Fig. 4. The processor 124 by reading the memory 126 is *S* able to load and execute the computer program 130.

The computer program may arrive at the apparatus 102 via any suitable delivery mechanism. The delivery mechanism may be, for example, a computer-readable storage medium, a computer program product, a memory device, a record medium such as a USB flash memory, an article of manufacture that tangibly embodies the computer program 130. The delivery mechanism may be a signal configured to reliably transfer the computer program 130.

Although the memory 126 is illustrated as a single component it may be implemented as one or more separate components some or all of which may be integrated/removable and/or may provide permanent/semi-permanent/ dynamic/cached storage.

The communication module 128 is configured to enable the apparatus 102 to communicate with other components and may provide a wireless and/or a wired link to the other components.

The communication device 104 functions as a communication interface between the apparatus 102 and the current transformer 106, the one or more smart plugs 108 and the one or more smart appliances 110. For example, the communication device 104 may be a modem that provides a wireless connection to the current transformer 106, the one or more smart plugs 108 and the one or more smart appliances 110, and a wired link to the apparatus 102 (e.g. via fibre optic cable). S...

The current transformer 106 may be any suitable device for monitoring an fl.

electrical parameter value of a signal flowing in a cable (e.g. current, power, energy) and then providing the monitored electrical parameter value to the apparatus 102 via the communication device 104. The current transformer 106 may be an apparatus 10 as described above with reference to figs. 1 and S. 2.

Smart plugs and smart appliances are well known in the art and will consequently not be described in detail here. Briefly, a smart plug/appliance is configured to receive a control signal and then control the power level of the plug/appliance in accordance with the control signal. Consequently, a smart plug/appliance may power on or off in response to receiving a control signal.

Furthermore, a smart plug/smart appliance may provide an alarm (e.g. an audible alarm or a visual alarm) in response to a control signal.

The one or more smart plugs 108 and the one or more smart appliances 110 are configured to receive control signals from the apparatus 102 to control the power level of the one or more smart plugs/appliances 108, 110. The one or more smart plugs 108 and the one or more smart appliances 110 are also configured to provide information to the apparatus 102 to identify a connected appliance or the smart appliance itself respectively.

The current transformer 106, the smart plug(s) 108 and the smart appliance(s) are, in this embodiment, located within a building 132.

The user input device(s) 112 may include any one or more suitable devices that enable a user to provide information to the apparatus 102. For example, the user input devices 112 may include one or more televisions, tablet computers, personal computers and mobile phones that are configured to execute an application for enabling information to be entered by a user and then transmitted to the apparatus 102.

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* The tariff server 114 is configured to determine an energy price tariff for a building (e.g. the building 132) based on the buildings electricity usage and/or electrical current used and/or peak load (provided by the current transformer 106) and information from a user identifying the one or more appliances a (which may have been entered via the user input device(s) 112). The tariff server 114 is also configured to provide the determined energy price tariff to

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the apparatus 102 to enable the apparatus 102 to determine predetermined electrical parameter values for one or more appliances that should not be exceeded. In some embodiments, the tariff server 114 may determine the predetermined electrical parameter values and then provide them to the apparatus 102. The tariff server 114 may have a similar structure to the apparatus 102 and include a processor, a memory and a communication module.

The electrical energy production of the power station/substation 122 is monitored by the grid monitor 120 and provided to the grid fingerprinting server 116 via the communication device 118. The grid fingerprinting server 116 is configured to monitor the energy production of one or more power stations/sub-stations 122 and provide the energy production information to the tariff server 114 to enable the tariff server 114 to re-calculate tariffs. The grid 1 5 fingerprinting server 116 may have a similar structure to the apparatus 102 and include a processor, a memory and a communication module.

The operation of the apparatus 102 is described in the following paragraphs with reference to figs. 3 and 4.

At block 134, the apparatus 102 receives second by second monitored electrical parameter values (e.g. electricity usage, current used, peak load) from the current transformer 106 that have been gathered other a period of time (e.g. 2 days) for the building 132. The computer program instructions 130 * 25 provide the logic and routines that enables the apparatus 102 to use a lookup table to compare the monitored electrical parameter values with energy used I....

by a range of known appliances. The apparatus 102 also provides a questionnaire to the one or more user input devices 112 to enable a user to identify the one or more appliances which have been active over the period of time. Once the user has completed and sent the questionnaire from the one 1''*'e4 or more user input devices 112, the questionnaire is then received at the apparatus 102. Information from the completed questionnaire regarding r�^ monitored electrical parameter values and identified appliances is entered into the lookup table to improve the accuracy and range of appliances contained in the questionnaire for other users. In some embodiments, the questionnaire may be supplemented or replaced with information from the smart plugs/appliances 108, 110 that identifies appliances that have been active over the period of time.

The apparatus 102 then provides the completed questionnaire and the monitored electrical parameter values to the tariff server 114 to enable the tariff server 114 to determine an energy tariff for the building 132. The tariff server 114 compares the state of an electrical energy grid (via the grid fingerprinting server 116) with demand for electrical energy from a plurality of buildings 132 to calculate the price of energy using a lookup table in order to balance energy consumption with energy production. For example, at peak times the tariff server 114 will seek to increase the price of energy to reduce energy demand. During low demand periods the tariff server 114 will seek to offer low energy prices to stimulate the use of energy to encourage the automatic use of appliances such as dishwashers or the charging of electric vehicles via the communication device 104. The apparatus 102 may then receive the energy tariff for the building 132 and then determine predetermined electrical parameter values that should not be exceeded by the appliances of the building 132. In other embodiments, the tariff server 114 may determine the predetermined electrical parameter values and then provide them to the apparatus 102.

S.....

* At block 136, the apparatus 102 receives an electrical parameter value for S *.S�* * one or more appliances in the building 132. For example, the apparatus 102 may receive an electrical current value from the current transformer 106 for the building 132. At block 138, the apparatus 102 determines if the electrical parameter value for an appliance (e.g. a dish washer) of the one or more ten..

appliances is greater than the predetermined electrical parameter value. If the received electrical parameter value is less than the predetermined electrical parameter value, the method returns to block 136.

If the received electrical parameter value is greater than the predetermined electrical parameter value, the apparatus 102 provides a control signal to the appliance to cause the appliance to provide an alarm to the user (e.g. audible or visual alarm) or to control the power level of the appliance (e.g. to power off the dish washer or to lower its power consumption by reducing the temperature of the dish washing water). The apparatus 102 may additionally or alternatively send a signal to the user input device(s) 112 to cause the user input device(s) 112 to provide an alarm to the user.

In some embodiments, the apparatus 102 may first control the appliance to provide an alarm, and if the electrical parameter value does not fall below the predetermined electrical parameter value after a period of time, to secondly control the appliance to power off. The method may then return to block 136.

A user may override the alarm and the change of power levels of the appliance. However, this may result in the user being charged at a rate which is higher than the tariff determined in block 134.

At block 142, the apparatus 102 receives information from the tariff server 114 indicating a change in the price of electrical energy. For example, the tariff server 114 may change the price of electrical energy based on changes to the :*i 25 load on the grid and the time of day. In response, the apparatus 102 changes the predetermined electrical parameter value using the received information to compensate for the price change. For example, if the price of electrical energy falls, the apparatus 102 may increase the predetermined electrical parameter value. Similarly, if the price of electrical energy increases, the :. 30 apparatus 102 may decrease the predetermined electrical parameter value.

It should be appreciated that block 142 may occur in the method at any point after step 134.

At block 144, the apparatus 102 receives information from the grid fingerprinting server 116 (via the tariff server 114) that indicates the state of an electrical energy grid (which may include one or more power stations and substations). The grid fingerprinting server 116 monitors the load of the electricity supply from one or more power stations/sub-stations 122 and uses a lookup table to calculate the load on the electrical energy grid. In response to the received information, the apparatus 102 provides a control signal to one or more appliances to control the power level of the one or more appliances in order to balance electrical energy demand with electrical energy production.

For example, the apparatus 102 may receive information that indicates that electrical energy production is low relative to demand and may then send a control signal to one or more appliances to power off.

It should be appreciated that block 144 may occur in the method at any point after step 134.

Embodiments of the invention provide several advantages. One such advantage is that the system 100 may enable a person to sign up to a particular energy tariff based on their electricity usage and the system 100 assists that person in controlling their energy usage in accordance with that rE tariff. This may help to reduce a person's electrical energy costs and may *:** 25 also help to reduce the waste of electrical energy. s.*

References to computer-readable storage medium', computer program product', tangibly embodied computer program' etc. or a controller', computer', processor' etc. should be understood to encompass not only computers having different architectures such as single /multi-processor architectures and sequential (Von Neumann)/parallel architectures but also specialized circuits such as field-programmable gate arrays (FPGA), application specific circuits (ASIC), signal processing devices and other processing circuitry. References to computer program, instructions, code etc. should be understood to encompass software for a programmable processor.

or firmware such as, for example, the programmable content of a hardware device whether instructions for a processor, or configuration settings for a fixed-function device, gate array or programmable logic device etc. As used in this application, the term circuitry' refers to all of the following: (a)hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of circuitry' applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit *:*** 25 or applications processor integrated circuit for a mobile phone or a similar integrated circuit in server, a cellular network device, or other network device" *.I.

S S...

The blocks illustrated in the Figs. 2 and 4 may represent steps in a method and/or sections of code in the computer programs 34, 130. The illustration of a particular order to the blocks does not necessarily imply that there is a required or preferred order for the blocks and the order and arrangement of the block may be varied. Furthermore, it may be possible for some blocks to be omitted.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed.

Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Although functions have been described wTh reference to certain features, those functions may be performable by other features whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

r1.t 25 I/we claim: * * ** * * * 30 S..

Claims

CLAIMS1. An apparatus for monitoring electrical current, the apparatus comprising: a current transformer for monitoring electrical current and providing a signal; and switching circuitry for receiving the signal from the current transformer and having a first electrical configuration in which the signal is provided to an energy storage device, and a second electrical configuration in which the signal is provided to measurement circuitry.
2. An apparatus as claimed in claim 1, further comprising the energy storage device, wherein the energy storage device includes one or more capacitors for storing electrical energy in the signal and for providing the stored electrical energy to at least the measurement circuitry.
3. An apparatus as claimed in claim 1 or 2, further comprising the measurement circuitry, the measurement circuitry including a processor for controlling the switching of the switching circuitry and for determining the monitored electrical current from the signal.
4. An apparatus as claimed in claim 3, further comprising a wireless transmitter for transmitting the determined monitored electrical current.
5. An apparatus as claimed in any of the preceding claims, wherein the *:***i 25 current transformer is configured to form a clamp with at least a portion of the apparatus for clamping a cable for monitoring electrical current in the cable. p...
6. An apparatus -substantially as hereinbefore described with reference to, and/or as shown in the accompanying figures.
7. A module comprising an apparatus as claimed in any of the preceding claims.
8. An energy management system comprising one or more apparatus as claimed in any of claims 1 to 6.
9. A method for monitoring current, the method comprising: controlling switching circuitry to switch between a first electrical configuration in which a signal from a current transformer is provided to an energy storage device, and a second electrical configuration in which the signal is provided to measurement circuitry.
10. A method as claimed in claim 9, further comprising determining a voltage value of the signal, controlling the storage of the voltage value and determining a monitored electrical current value of the signal from the stored voltage value.
11. A method as claimed in claim 10, further comprising controlling a wireless transmitter to transmit the determined electrical current value.
12. A method substantially as hereinbefore described with reference to, and/or as shown in the accompanying figures.
13. A computer program that, when executed by a processor, executes a method as claimed in any of claims 8 to 10. * *

*..*. 25
14. A computer-readable storage medium encoded with instructions that, when executed by a processor, perform a method as claimed in any of claims 9 to 12.
15. A method for electrical energy management, the method comprising: receiving an electrical parameter value for one or more appliances; determining if the electrical parameter value for an appliance of the one or more appliances is greater than a predetermined electrical parameter value; and providing a control signal to the appliance to perform a first action if the determined electrical parameter value for the appliance is greater than the predetermined electrical parameter value.
16. A method as claimed in claim 15, wherein the first action is providing an alarm to a user.
17. A method as claimed in claim 15, wherein the first action is powering off of the appliance.
18. A method as claimed in any of claims 15 to 17, wherein the electrical parameter value is an electrical current value, and the predetermined electrical parameter value is a predetermined electrical current value.
19. A method as claimed in any of claims 15 to 18, further comprising providing a questionnaire to a user input device for enabling a user to identify the one or more appliances; receiving the completed questionnaire from the user input device; and providing the completed questionnaire to a tariff server for determining an energy tariff.
20. A method as claimed in any of claims 15 to 19, further comprising :... 25 receiving information indicating a change of electrical energy price and changing the predetermined electrical energy value using the received information.
21. A method as claimed in any of claims 15 to 20, further comprising receiving information indicating the state of an electrical energy grid; and providing a control signal to the one or more appliances to control the power level of the one or more appliances for balancing electrical energy demand with electrical energy production.
22. A method substantially as hereinbefore described with reference to and/or as shown in the accompanying figures.
23. An apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform a method as claimed in any of claims 15 to 22.
24. A system for electrical energy management comprising an apparatus as claimed in claim 23 and one or more apparatus as claimed in any of claims 1 to 6.
25. A computer program that, when executed by a processor, executes a method as claimed in any of claims 15 to 22.
26. A computer-readable storage medium encoded with instructions that, when executed by a processor, perform a method as claimed in any of claims to 22.* * **** * * *:* 25
27. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims. ***.*** * * * 30 ***S