FIELD OF THE INVENTION The invention relates to the field of monitoring and controlling a utility supply such as an electricity supply to consumers such as households or offices. The invention more specifically relates to an analysis of the consumption and a subsequent adjustment in order to obtain an efficiency gain. BACKGROUND OF THE INVENTION

At present, the costs of energy consumption, e.g. the consumption of electricity, are ever increasing. At the same time, consumers, such as households or companies are urged to reduce their energy consumption, or are forced to do so via legislative initiatives. In order to provide insight in the energy consumption, devices are on the market that enable a real-time monitoring of e.g. electricity consumption. Such devices are further capable of assessing the type of load is e.g. connected to the power supply. This type of assessment is e.g. known as non-intrusive utility or load monitoring. Based on e.g. a monitoring of a supply voltage (e.g. a mains voltage provided to a house or office) and a supply current, such devices may provide feedback, e.g. via a display of a user interface, on the type of load (specific appliances, lighting) and the amount of power consumed by the different loads. As such, based on the sensed voltage and current, the device can disaggregate a number of loads and provide feedback to the customer on the power consumption of the different loads.

Further, devices, known as smart plugs, are on the market that facilitate power savings by e.g. disconnecting appliances when operating in standby. Such devices, which can e.g. be fitted into a mains outlet, are often programmable and may e.g. have networking facilities to enable control of the smart plug or to provide data from the smart plug to a central processing unit.

As such, various devices are currently available that enable to some extent power savings or provide insight in power consumption.

It is further know to adjust an incoming voltage to a nominal mains supply voltage using a transformer or the like. SUMMARY OF THE INVENTION

It would be desirable to provide a device that facilitates taking appropriate measures with respect to power savings based on an analysis of a power consumption.

To better address one or more of these concerns, there is provided a method of controlling a power consumption of a plurality of appliances, the method comprising:

identifying the plurality of appliances;

determining a power consumption of each of the identified plurality of appliances based on the current signal representing a total current supplied to the plurality of appliances and a voltage signal representing a supply voltage of the plurality of appliances;

controlling an operating state of at least one of the plurality of appliances by providing a control signal including an identifier of the at least one of the plurality of appliances to the plurality of appliances, whereby the control signal is provided to the plurality of appliances using a PLC protocol.

In an embodiment, the identification of the plurality of appliances is obtained by either:

• receiving a current signal representing a total current supplied to the plurality of appliances and;

• analyzing the received current signal to obtain an identification of at least one of the appliances; or by:

• providing a polling signal to the plurality of appliances using a PLC protocol and;

• receiving a reply signal from at least one of the appliances, using the PLC protocol, whereby the reply signal comprises an identification of the at least one of the appliances.

In accordance with the invention, a method is provided whereby an operating state of an identified appliance is controlled using a PLC protocol. Such a PLC (Power Line

Communication) protocol based communication enables the control of appliances by e.g. an analyzing tool (see further on) without the need to install additional communication networks or the like. Using PLC, control of an appliance, i.e. of an operating state of an appliance is established via the power grid available to power the appliance.

In order to control a power consumption of a customer such as a household or an office, the method according to the invention first provides in an identification of the appliances that are powered. In general, in a household or an office, several appliances are operating at the same time, each consuming part of the power supplied. Many appliances are however found to have a particular power characteristic, e.g. a particular current profile (e.g. a particular harmonic content of the current) that enables an identification of an appliance based on the current supplied to the appliance. As such, a particular current profile can be considered a fingerprint or signature of a particular appliance. When such fingerprints or signatures of the appliances (or at least part of the installed appliances, e.g. the appliances that are

responsible for a comparatively large portion of the power consumption) are known, an analysis of a total current supplied to a customer can be disaggregated into different components which can be attributed to different appliances.

At present, devices are on the market that provide such a so-called non-intrusive utility monitoring and can thus provide such a disaggregation and an identification of appliances that are powered. In this respect, reference can e.g. be made to UK-based company Navetas or to US 201 1/0025519.

In an embodiment, the identification is based on both the current profile and the

corresponding supply voltage, thus enabling to assess both the active and reactive power consumed by the appliances.

Nowadays, more and more appliances (in particular lighting equipment) are adapted to receive a control signal via the power grid, i.e. applying a PLC protocol. Given this, an identification of one or more of the appliances can be facilitated; therefore, in accordance with the present invention, the identification of an appliance may also be obtained by receiving a feedback from an appliance on a polling signal. In accordance with the present invention, polling (or providing a polling signal) is used to describe a probing or sampling of the power grid powering the plurality of appliances to retrieve information from the appliances. When an appliance (e.g. a lighting equipment) is adapted to receive and transmit signals according to a PLC protocol, it may, upon receipt of a polling signal, transmit a signal containing an identification or identifier of the appliance onto the power grid.

Using such an identifier, (e.g. including information on the type or appliance, brand, serial number, ... ) an expected power consumption or current profile of the appliance can be determined. When one or more appliances are thus identified, i.e. identified on the basis of an identifier received in reply to a polling signal, a disaggregation (i.e. an identification) of the remaining appliances (if any) based on an analysis of the received current signal is facilitated. In accordance with the method according to the present invention, the power consumption of the identified appliances is subsequently determined and controlled, whereby the controlling involves controlling an operating state of at least one of the appliances by using a PLC protocol to provide a control signal containing an identifier of the appliance to be controlled. In accordance with the present invention, controlling an operating state can e.g. refer to turning an appliance on or off or changing an operating state to a different power

consumption level.

In an embodiment, the step of controlling an operating state of at least one of the plurality of appliances is preceded by the step of: providing an inquiry to the consumer requesting an authorization for controlling the operating state.

As such, prior to providing the control signal to change an operating state, an authorization is asked to a consumer. Such authorization can e.g. be asked via an electronic message such as a text message or an e-mail or the like to e.g. a Smartphone or notebook can be accessible via a Smartphone application or App.

As an alternative, or in addition, a status report can be provided to a customer (in a similar manner, via an electronic message) informing the customer about a changed operating state of an appliance.

In an embodiment, the step of controlling an operating state of at least one of the plurality of appliances is preceded by the steps of:

receiving an occupancy signal indicative of an occupancy of a consumer; assessing a necessity of the power consumption of the identified one or more appliances based on the occupancy signal;

Based on the assessment of the necessity of the power consumption it may thus be decided to change an operating state of one or more of the plurality of appliances.

In an embodiment, the method further includes the step of:

determining a minimized power consumption of the plurality of appliances based on the necessity.

In the latter methods according to the invention, a power consumption of one or more appliances (whereby the appliances are identified in a similar manner as discussed above) is evaluated to establish the necessity (or usefulness) of the power consumption by using an occupancy signal. In accordance with the present invention, the feature Occupancy signal' is used to denote information on the use of the building or office, which can e.g. be reflected by the occupancy or presence of inhabitants (in case of a household) or employees (in case of an office or the like) in the house or office where the appliances are used.

In an embodiment, this information can be generated automatically, e.g. the occupancy signal being based on feedback from an occupancy sensor or other detector such as a card reader. In an embodiment, the occupancy signal can be a schedule indicative of the use or occupancy of the house or office. Such a schedule can e.g. be inputted (via a user interface) by a user and can e.g. be in the form of a time schedule such as a week schedule indicating for each day when the house or office is occupied. Alternatively, or in addition, such an occupancy signal can e.g. be provided by electronic messaging, e.g. text messaging or via a Smartphone App.

In an embodiment, such occupancy signal or information may include further details on a preferred use (or non-use) of certain appliances. Such information can e.g. include that certain appliances need to be turned on at all times or can describe a preferred use of appliances in relationship with the occupancy.

In an embodiment, the current signal is analyzed over a period T and the occupancy signal comprises an occupancy schedule of the customer over the period T.

Such a period T can e.g. span several days or weeks, whereas the current signal is e.g. analyzed at a comparatively high rate, e.g. once every 5 min or 15 min.

In accordance with the fifth aspect of the invention, the necessity of the powering the one or more identified appliances can be assessed by using the occupancy signal or information. As an example, when the occupancy signal indicates that the house or office is vacant or unoccupied during a week-end, this information can be compared with the power consumption during this week-end and, for each of the appliances powered, it can be determined if this appliance needs to be powered, i.e. the necessity of the power

consumption is determined, given the provided occupancy.

By doing so, the method according to these embodiments provides insight in the power consumption and the usefulness of this consumption. In addition, the method may provide in determining a minimized power consumption based on the necessity. This can e.g. be done by disregarding the power consumption of these appliances that have a low necessity (e.g. for certain periods of time that can be determined from the occupancy signal), e.g. due to the absence of the inhabitants or employees.

Once such minimized power consumption is determined, it may e.g. be included in an inquiry that is send to the consumer to provide the consumer with insight in possible savings when the operating state of one or more appliances is changed, in view of the occupancy.

Using the methods mentioned, insight is provided in the power consumption and enables to identify instances or periods (using the occupancy signal) when certain appliances could be turned off, in order to save energy.

In order to facilitate such energy savings, electrical devices that can disconnect an appliance from an electric grid (e.g. a mains supply voltage) by receiving a control signal can be installed at the appropriate appliances. Such devices are further on referred to as remotely controllable electrical switches. In this respect, reference can e.g. be made to WO

2008/088219 disclosing electrical devices comprising a controllable switch and a receiver for receiving a control signal for controlling the switch. Such devices can e.g. take the form of a wall plug that can be plugged in an existing wall socket and comprises a wall socket for receiving a plug of an appliance or can take the form of a connector to connect two cable ends.

Note that, as mentioned, certain appliances that are currently available, already allow a controlling of an operating state using the PLC protocol. Other appliances which do not have this functionality yet, may be controlled by installing the mentioned remotely controllable electrical switches.

In an embodiment of the method according to the invention, such remotely controllable electrical switches are controlled by using a PLC protocol (Power Line Communication). In accordance with an embodiment of the method according to the invention, one or more of the identified appliances are indentified as suitable candidates for the application of an active control of the power consumption. Such an identification can e.g. be based on the determined necessity of the power consumption of the appliances and/or on the amount of power consumed.

Since the installation of remotely controllable electrical switches may be time consuming and expensive, it may be preferred to install such switches only for a selected number of appliances, i.e. the appliances that are identified and which can, when turned off at suitable instances or periods derived from the necessity, provide in an energy savings. As will be understood, the installation of such remotely controllable electrical switches is most beneficial in case the energy savings that are achievable are important.

As such, in an embodiment, the method according to the present invention provides in a selection of one or more of the identified appliances to which an active control of the power consumption may be applied. Within the meaning of the present invention, the term active control of the power consumption of an appliance is used to denote the application of a remotely controllable electrical switch to control the power consumption of an appliance.

Subsequently, the method can provide, in an embodiment, in the installation of the remotely controllable electrical switches at the appropriate appliances. In a next step, the method according to the present invention can provide in controlling the installed electrical switches based on the necessity derived.

In an embodiment, the method of controlling a power consumption further provides in transforming an incoming voltage to a supply voltage for powering the plurality of appliances, whereby the method further comprising:

determining an optimal supply voltage for the plurality of appliances based on the identification and the power consumption;

- assessing a difference between the optimal supply voltage and the incoming voltage;

controlling the supply voltage to substantially match the optimal supply voltage when the difference meets a predefined criterion.

In accordance with the embodiment, a method is presented that facilitates an optimization of a supply voltage that is used to power one or more appliances. The method is particularly suited for implementation in comparatively small consumers of electricity such as households, small offices or SMEs. The method as proposed can be implemented without making substantial modifications to an existing electrical installation. The method as proposed enables to adjust an incoming voltage of an electrical grid (e.g. 250 V) to a supply voltage most suited in a given load situation.

In accordance with the present invention, the term incoming voltage is used to denote the voltage as provided by the electrical grid outside a consumer such as a household, office or SME. Typically, such a voltage can e.g. be around 240 V +/- 10%. In general, this incoming voltage may vary, e.g. depending on the time of day or a position of the consumer in the electrical grid. In general, the incoming voltage will deviate, to some extend, from a nominal voltage that is specified for many applications or appliances. Further, manufacturers of appliances (such as lighting equipment, HVAC equipment, electrical furnaces, etc .. ) may further specify an optimal voltage (optimal w.r.t. efficiency) for operating the equipment. This voltage may e.g. correspond to the nominal voltage of the equipment or may be different. Further, it can be noted that the optimal operating voltage need not be the same for each type of equipment.

In view of this, the method provides in an analysis of the electric power consumed by a customer (e.g. a household or a small office) by receiving (e.g. from a current sensor) a signal representing a current value of a total current supplied to one or more appliances.

In accordance with the embodiment, the identification is further used to determine an optimal supply voltage for powering the load that is represented by the total current. As mentioned, an optimal operating voltage for a particular electrical appliance may be specified by a

manufacturer.

In an embodiment, the optimal supply voltage is determined as the optimal operating voltage of the appliance that consumes a comparatively large portion of the power supplied. In such embodiment, the analysis may thus include determining a relative power consumption of the appliances that are powered. This relative power consumption (e.g. expressed as

percentages of the total power consumption) may e.g. be used to determine an optimal supply voltage. In an embodiment, the relative power consumption is used as weight factor for determining the optimal supply voltage.

In an embodiment, an efficiency characteristic of the identified appliances is used to determine an optimal supply voltage. Such a characteristic may e.g. be made available from a manufacturer's database and may describe the efficiency of an appliance as a function of the supply voltage.

When the optimal supply voltage is determined, it is compared to the incoming voltage. Based on this comparison, the incoming voltage can be controlled, i.e. adjusted to substantially match the optimal supply voltage, when the difference between the incoming voltage and the optimal supply voltage meets a predefined criterion. As an example, the incoming voltage can e.g. be adjusted when it is outside a predefined bandwidth of the optimal supply voltage. When the incoming voltage is found to substantially match the optimal supply voltage, no adjustment needs to be made and the incoming voltage may readily be applied as the supply voltage.

In an embodiment, the step of determining the optimal supply voltage includes consulting a database containing information on a power requirement of the one or more appliances. Such a database can e.g. be consulted via a communication network such as a wireless communication network whereby a signal indicating the identified appliance or equipment is transmitted to the database and a signal representing the power requirements (e.g. nominal voltage, optimal voltage, etc .. ) of the identified appliance or equipment is received from the database. Using such a communication link renders the described method more flexible with respect to changes in the appliances or equipment installed.

In an embodiment, the step of identifying the one or more appliances may also make use of a database, e.g. accessible via a communication network, for obtaining information that can facilitate the identification of a particular appliance. As such, the fingerprints, as mentioned above, of an appliance can be retrieved from a database for comparison. As an alternative, the step of analyzing the total current can be performed at a central processing unit having access to the database. In such arrangement, the total current supplied to the one or more appliances can e.g. be sampled and the sampled current can be transmitted, via a

communication network, to a processing unit for analysis. In a similar manner, when the identification is based on a reply signal received in response to a polling signal, an identifier contained in the reply signal can be used to retrieve operating characteristics of the appliance from a database.

In an embodiment, the step of analyzing the total current value can be performed for a plurality of customers by a common processing unit having access to a database which can e.g. comprise the aforementioned fingerprints and/or power requirements.

With respect to the adjustment of the incoming voltage to an optimized supply voltage, it can be mentioned that such an adjustment may also reported to a customer by sending an electronic message describing the adjustment made.

In an embodiment, any of the adjustments made (either to an operating state or a supply voltage) may be logged, whereby a power consumption of the plurality of appliances is recorded and compared with a calculated power consumption when the adjustment would not have been made. Using such a logging, which can e.g. be provided at regular time intervals to the consumer, insight can be provided with respect to energy savings that have been realized. Such a logging can e.g. be provided to the customer by electronic messaging such as e-mail or text-messaging or via a Smartphone App, or can be made available to the customer using near field communication.

In accordance with another aspect of the present invention, there is provided an apparatus for controlling a power consumption of a plurality of appliances of a consumer, the apparatus comprising:

an analyzing unit comprising:

o a current input terminal for receiving a current signal representing a total current supplied to the plurality of appliances;

o a voltage input terminal for receiving a voltage signal representing the incoming voltage;

o an output terminal comprising a PLC transmitter for providing a control signal to a power grid powering the plurality of appliances;

o a processing unit, the processing unit being arranged to:

o receive the current signal and the voltage signal;

o determine an identification of the plurality of appliances;

o determine a power consumption of the identified plurality of

appliances based on the current signal and the voltage signal; o determine the control signal for controlling an operating state of at least one of the plurality of appliances, the control signal including an identifier of the at least one of the plurality of appliances, and o providing the control signal to the PLC transmitter for transmission to the plurality of appliances.

In an embodiment, the processing unit is further arranged to:

• determining an optimal supply voltage based on the identification and power consumption;

• estimate a power consumption of the one or more appliances when powered by the optimal supply voltage;

• assess a difference between an actual power consumption calculated from the current signal and the voltage signal and the estimated power consumption, and wherein the apparatus further comprises a voltage control unit comprising

o a signal input terminal for receiving a voltage control signal

representing the optimal voltage;

o a voltage input terminal for receiving the incoming voltage o a voltage output terminal for providing a supply voltage for powering the one or more appliances;

o a voltage adjustment circuitry connected to the voltage input

terminal and the voltage output terminal for converting the incoming voltage to the supply voltage;

wherein the voltage control unit is further arranged to control the voltage adjustment circuitry to convert the incoming voltage to the optimal supply voltage based on the voltage control signal, when the difference meets a predetermined criterion.

In order to e.g. perform the method according to the present invention, an apparatus is provided that comprises an analyzing unit. In accordance with the invention, the analyzing unit comprises a current input terminal for receiving an input signal representing a total current supplied to one or more appliances.

The analyzing unit further comprises an output terminal comprising a PLC transmitter for providing a control signal to a power grid powering the plurality of appliances. By using such a transmitter, an operating state of one or more of the appliances can be controlled. In an embodiment, the analyzing unit may also comprises a current sensor connected to the input terminal, the current sensor being arranged to measure the total current supplied to the appliance(s). In accordance with an embodiment the invention, the input signal is provided to a processing unit of the apparatus in order to analyze the input signal to obtain an

identification of the one or more appliances and determine an optimal supply voltage based on the identification.

Note that the processing unit of the analyzing unit need not be directly connected to the input terminal receiving the input signal. In an embodiment, the analyzing unit comprise a transmitter for transmitting the input signal (which can e.g. be a sampled total current) to the processing unit for analysis.

In an embodiment, the processing unit, which can e.g. comprises a processor, a

microcontroller or the like, is arranged to determine an identification of the plurality of appliances.

In an embodiment, the processing unit is arranged to disaggregate the input signal into different components, each component representing a current or current profile of an appliance. In such embodiment, each component may subsequently be compared to current or current profiles of know appliances, which are e.g. stored in a database that is accessible to the processing unit.

In order to establish such an identification, the processing unit can e.g. be arranged to apply mathematical signal processing techniques such as Fourier transformations or the like.

As an alternative, or in addition, the processing unit can be arranged to: • provide a polling signal to the plurality of appliances using the PLC transceiver;

• receiving a reply signal from at least one of the appliances, using the PLC protocol, the reply signal comprising an identification of the at least one of the appliances and

In such embodiment, use is made of a PLC transceiver of the analyzing unit of the apparatus according to the invention. With respect to the application of a polling signal, reference is made to the above description of the method according to the invention.

Based on the identification, the processing unit may determine an optimal supply voltage and provide a signal representing this optimal voltage to a voltage control unit that comprises a voltage adjustment circuit.

In accordance with an embodiment the invention, the voltage control unit is arranged to receive an incoming voltage (e.g. from an electrical grid) at a voltage input terminal and provide, via a voltage output terminal, a supply voltage, whereby a voltage adjustment circuit is provided to convert the incoming voltage to the supply voltage.

In accordance with the invention, the voltage adjustment circuit (which can e.g. comprise a variable transformer) is controlled based on the signal representing the optimal supply voltage.

As such, in case the incoming voltage would substantially correspond to the optimal supply voltage, the voltage adjustment circuit can be controlled such that incoming voltage remains unchanged, e.g. by applying a transformation ratio of 1 in a transformer of the voltage adjustment circuit. Alternatively, the voltage adjustment circuit can comprise a bypass thereby applying the incoming voltage as the supply voltage without any transformation, when the incoming voltage substantially matches the optimal supply voltage.

In an embodiment, the voltage terminals of the voltage control unit are adapted to receive and provide a three-phase voltage; the voltage adjustment circuit being arranged to convert a three-phase incoming voltage to a three-phase supply voltage.

In such arrangement, the voltage adjustment circuit may further be arranged to improve a balancing between the three phases. The voltage adjustment circuit may also include an harmonic filter to provide in an attenuation of Total Harmonic Distortion (THD). In an embodiment, the application of such a filter may be based upon the identification of the appliances that are powered. In this way, additional losses caused by the application of the harmonic filter can be avoided when the filter is not needed, e.g. because the identified load is known not to cause an important harmonic distortion.

In an embodiment, the apparatus may further comprise a user interface for providing feedback to the user or enabling the user to provide data to the apparatus. As an example of the former, the user interface may comprise a display providing information on the actual consumed power, e.g. indicating the identified loads or appliances. Such a display may further provide feedback on the applied voltage adjustment.

In an embodiment, the optimal supply voltage is determined at a predetermined rate, e.g. every 5 or 15 min. As an alternative, the determination of the optimal supply voltage can be triggered by a detected change in the input signal which represents a change in the total current and thus the load situation.

As will be clear from the above, the application of the method according to the first aspect of the invention, which can e.g. be implemented by the apparatus according to the invention, enables to optimize a supply voltage applied to one or more appliances by applying an adjustment of an incoming voltage to better match an optimal supply voltage . Because the implementation of such an optimization requires the installation of the voltage adjustment circuit (which could be an important investment, depending on the required functionality), it might be useful for a customer such as a household or an office, to know beforehand if the installation of such an apparatus would be useful. As will be understood, the effectiveness of applying a voltage adjustment circuit may depend on a deviation between the applied supply voltage (corresponding to the incoming voltage if no measures are taken) and an optimal supply voltage.

In an embodiment, the analyzing unit further comprises:

o a terminal for receiving an occupancy signal representing an

occupancy of the customer;

and wherein the processing unit is arranged to:

o receive the occupancy signal;

o assess a necessity of the power consumption of the identified one or more appliances based on the occupancy signal;

o determine a minimized power consumption of the one or more

appliances based on the necessity; and

o provide an inquiry to the customer requesting an authorization for controlling the operating state. Using such an apparatus, insight can be provided in the power consumption of a customer whereby this power consumption is correlated with an occupancy signal, thereby providing feedback on the necessity of the power consumption and providing feedback on a possible energy savings. In order to realize this, the apparatus according to comprises a processing unit for processing a current signal to identify appliances that are powered and assess the necessity of the power consumption of the indentified appliances, using an occupancy signal.

In an embodiment, the apparatus comprises an output terminal for providing an output signal representing a difference between the power consumption and the minimized power consumption. Such an output signal can e.g. be a graph, representing the difference (as a function of time t) or can e.g. be an indication of potential energy savings (expressed in kWh) that can e.g. be displayed on the aforementioned display.

In accordance with a further aspect of the present invention, an active control of the power consumption of one or more appliances can be established based on the necessity or the information derived from the comparison of the actual power consumption and the minimized power consumption.

In an embodiment, the processing unit comprises an output terminal for providing an electronic message to the customer, the electronic message comprising the inquiry.

In a further embodiment, as will be explained in more detail below, the apparatus according to the present invention enables so-called power shaving whereby the power consumption of one or more appliances is controlled such that a desired (total) power level is attained. By an appropriate control of the remotely controllable electrical switches, and optionally taking into account an occupancy of the household or office, one can ensure that a total power consumption does not exceed a predetermined or desired threshold.

These and other aspects of the invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols designate like parts.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 a depicts a flowchart of a first embodiment of the method according to the invention.

Figure 1 b depicts a flowchart of a second embodiment of the method according to the invention.

Figure 2 depicts a flowchart of a third embodiment of the method according to the invention.

Figure 3 depicts a flowchart of an fourth embodiment of the method according to the invention.

Figure 4 schematically depicts a first embodiment of an apparatus according to the invention.

Figure 5 schematically depicts a second embodiment of an apparatus according to the invention.

Figure 6 schematically depicts a third embodiment of an apparatus according to the invention.

Figure 7 schematically depicts a fourth embodiment of an apparatus according to the invention. DETAILED DESCRIPTION OF EMBODIMENTS

In Figure 1a, a flowchart is shown of a method of controlling a power consumption of a plurality of appliances according to the invention. The method comprises a first step 10 of identifying the plurality of appliances. In accordance with the present invention, such an identification can either be performed by (step 20) analyzing a current signal representing a total current supplied to the appliances (see further on) or by (step 30) providing a polling signal (using a PLC protocol) and obtaining a reply signal (from one or more of the

appliances), using the PLC protocol, the reply signal comprising an identification of the appliance.

Nowadays, more and more appliances (in particular lighting equipment) are adapted to receive a control signal via the power grid, i.e. applying a PLC protocol. Given this, an identification of one or more of the appliances can be facilitated; therefore, in accordance with the present invention, the identification of an appliance may also be obtained by receiving a feedback from an appliance on a polling signal. When an appliance (e.g. a lighting

equipment) is adapted to receive and transmit signals according to a PLC protocol, it may, upon receipt of a polling signal, transmit a signal containing an identification or identifier of the appliance onto the power grid.

Using such an identifier, (e.g. including information on the type or appliance, brand, serial number, ... ) an expected power consumption of the appliance can be determined. When one or more appliances are thus identified, i.e. identified on the basis of an identifier received in reply to a polling signal, a disaggregation (i.e. an identification) of the remaining appliances (if any) based on an analysis of the received current signal is facilitated.

In a next step, step 40, the method provides in determining a power consumption of the appliances. This can e.g. be establish on the basis of a current signal representing the current provided to the appliances and a voltage signal represent the supply voltage to the

appliances.

In a next step, step 50, a PLC protocol is used to control an operating state of one or more of the appliances. This can e.g. be establish by providing a control signal containing an identification (also referred to as identifier) of the appliance to be controlled, to the plurality of appliances. In case the appliance itself is not equipped to receive a PLC control signal and in response, alter an operating state, use can be made of remotely controllable electronic switches that can be PLC controlled and which can be connected between the power grid and an appliance (see also further on).

In an embodiment, the step of controlling the operating state is preceded by the following steps, schematically shown in Figure 1 b: In step 42, an occupancy signal is received, the signal providing information on the occupancy of the household of office by the customer. Such occupancy signal can e.g. be obtained from an occupancy sensor or a card reader or can comprise a schedule indicating the occupancy for a given period of time. In such case, this schedule can e.g. be stored in an accessible database or memory unit, whereby such a database of memory unit has been provided with the schedule via a user interface by the customer. In a next step 44, a necessity of the power consumption of the identified appliances is determined based on the occupancy signal. To illustrate this, in case the occupancy signal is a schedule indicating that the office or house will not be occupied over a certain period (e.g. a weekend), it can be assessed that applications such as lighting or HVAC installations need not be powered. As such, the necessity of powering these appliances can be determined as "LOW" or zero. In accordance with the present invention, the term or feature 'necessity' is thus used to indicate whether or not it is required or useful to power a specific appliance, based on an occupancy signal.

Note that, in general, the occupancy signal can be indicative of a general occupation or use of a house or office, or can be more detailed, e.g. indicating the occupancy of certain rooms or floors in an office.

Based on the determined necessity, a minimized power consumption may subsequently be determined (not shown) indicative of the required or useful power consumption, given a certain occupancy.

Implementation of this minimized power consumption can subsequently be established by controlling the operating state of one or more of the appliances (i.e. the implementation of step 50 of Figure 1a).

Prior to the implementation of step 50, the method according to an embodiment of the present invention may provide in (see step 46) providing an inquiry to the customer requesting an authorization to control the operating state. Such a request can e.g. be provided to the customer by an electronic message (Text-message, e-mail or the like) which may e.g. include a proposed change in operating state of one or more appliances. Such a proposal may e.g. refer to turning of an HVAC installing or lighting equipment.

In an embodiment, the method may further include the step of enabling the customer to adjust or modify the proposed adjustments to the operating states.

In an embodiment, the current signal is analyzed over a period T and the occupancy signal comprises an occupancy schedule of the customer over the period T.

In an embodiment, the method further provides in a step of providing information to the customer on a difference between the minimized power consumption and the power consumption and/or the necessity. Such information can e.g. be made available via a user interface or a webpage accessible to the customer or can be included in the inquiry provided to the user / customer. As the method as described provides insight in the usefulness or necessity of the power consumption, it may be advantageous to take appropriate measures in response to the gained insight.

As such, in an embodiment, the method as illustrated in Figure 1 b may further comprise the steps of:

selecting of one or more of the identified appliances for active control of the power consumption;

installing remotely controllable electrical switches for controlling the power of the selected identified appliances;

- controlling the installed electrical switches based on the necessity.

In the embodiment of the present invention, an active control of the power consumption of a selected number of appliances is performed by the installation of remotely controllable electric switches.

Note that such installation may not be required for those appliances that are already capable of receiving and processing PLC type control signals.

Such remotely controllable electrical switches can disconnect an appliance from an electric grid (e.g. a mains supply voltage) by receiving a control signal (e.g. via the aforementioned PLC protocol). Using the method as described in Figure 1 b, a selection can be made of the appliances that can provide the most energy savings when the powering of these appliances is controlled, based on the necessity. In this respect, reference can e.g. be made to WO

2008/088219 disclosing electrical devices comprising a controllable switch and a receiver for receiving a control signal for controlling the switch. Such devices can e.g. take the form of a wall plug that can be plugged in an existing wall socket and comprises a wall socket for receiving a plug of an appliance or can take the form of a connector to connect two cable ends.

By selecting the required controllable switches, the installation costs of such switches is optimized.

In a further embodiment of the method according to the invention, optimizing a supply voltage is provided. In Figure 2, a flowchart is shown of a method enabling the provision of an optimized supply voltage, derived from an incoming voltage as e.g. received from an electric grid, to an electric load which can contain one or more different equipments or appliances. In a first step 1 10 of the method, a value of a total current provided to a particular installation (or customer) comprising one or more appliances is received. Such a current value can e.g. be provided by an electricity meter which can measure a total instantaneous current to all appliances that are powered. In order to measure the current, a current clamp, a current transformer or a Hall-sensor could be applied. Other suitable ways to measure the current could be considered as well. In a second step 120, an identification of the appliances is obtained, which can be done as explained w.r.t. Figure 1 a, i.e. either by an analysis of the current value in order to identify the one or more appliances that are powered or by a polling process probing the power grid for appliances having a PLC interface.

In order to identify the appliances that are powered based on the analysis of the current to the appliances, use can be made of one or more of the following features of the obtained current value:

- total real power consumption;

- phase angle of the power consumption;

- current wave shape, including e.g. harmonic content of the current supplied.

- etc...

In order to assess these features, the total current as supplied to the one or more appliances can e.g. be sampled (at a comparatively high frequency, e.g. > 5 kHz) and processed using digital signal processing equipment.

Examples of processing modules enabling such identification of an appliance, based on an observed current are e.g. described in US 2011/0025519 or WO 201 1/012840.

It may be worth noting that the analyzing step 120 as indicated may be performed in two separate stages; a first stage aiming at identifying which appliances are connected to an electric network of a customer and a second stage aimed at identifying which appliances are powered at a particular instance or within a particular time frame.

When the appliances that are connected in a particular network (e.g. a household or small office) are known beforehand (and their respective characteristic power consumption), the identification of appliances in the second stage can be facilitated.

In a third step 130, an optimal supply voltage is determined using the identification of the one or more appliances that are powered. In general, appliances are designed to suitably operate within a voltage range, but may have an optimal operating voltage that can e.g. be based on considerations such as lifetime or efficiency. As such, when an appliance is supplied with a voltage that is different from its optimal voltage, the lifetime or efficiency may be adversely affected. When the one or more appliances that are powered, are identified, an optimal supply voltage can be determined, e.g. based on characteristic data as provided by the manufacturers or suppliers of the appliances.

In case different appliances that are powered would have a different optimal supply voltage, a weighted average of the optimal voltages could be applied, e.g. based on the power consumption of the appliances. Alternative ways of determining the optimal voltage could be considered as well.

When determining the optimal voltage, one may also take certain constraints posed by certain loads into account. Such constraints could e.g. include minimal voltages for proper operation. In a fourth step 140 of the method according to the invention, an incoming voltage, i.e. the voltage as received from the electrical grid, is compared to the determined optimal voltage. In general, the incoming voltage, e.g. 250 V, will be higher than the optimal voltage, e.g. 220 V.

In a fifth step 150, the supply voltage is controlled to substantially match the optimal supply voltage when the difference between the incoming voltage and the optimal voltage meets a predefined criterion. As an example, when the optimal supply voltage, as determined in step 130 is found to be not within x % of the incoming voltage (x e.g. being 2 or 3 %), the supply voltage, derived from the incoming voltage, is adjusted.

In case the incoming voltage would be such that the optimal supply voltage is within x % of the incoming voltage, the incoming voltage is readily applicable to supply the appliances. In a further embodiment of the method according to the invention an assessment of the supply voltage as provided by the electrical grid is made, to determine the usefulness of applying a voltage control unit (see further on) for controlling an incoming voltage.

In Figure 3, a flowchart is shown of a method according to a third aspect of the present invention. As shown, in steps 310 and 320, a current and voltage signal are received, whereby step 330 provides in an identification of the appliances. Again, this can either be established using the current signal whereby the current signal is used to determine the identify the one or more appliances that are powered (in a similar manner as disclosed above) or by using the polling procedure as described whereby an identification is obtained from those appliances arranged to communicate via a PLC protocol. In next steps 340 and 350, an assessment is made of the optimal voltage for supplying the identified appliances (340) and the power consumption of the one or more appliances is estimated, in case the appliances would be powered by the optimal supply voltage. In order to determine the power consumption of the one or more appliances at a given supply voltage, manufacturing data of the indentified appliances or mathematical models describing the electrical behavior of the appliances can be used. Such information can e.g. be made accessible for a processing unit that performs the steps 340 - 360 via a communication link of any suitable type. In step 360 of the method described, a difference between the actual power consumption and the estimated (optimal) power consumption is determined.

Such difference, which can e.g. be used to calculate a pay-back period of a voltage control unit (see further on) can e.g. be outputted to a user interface or made accessible for a user (e.g. via a webpage, or via electronic messaging)

In Figure 4, an embodiment of an apparatus according to the second aspect of the present invention is schematically shown. The apparatus as shown in Figure 4 comprises an analyzing unit 410 comprising a voltage terminal 420 for receiving a signal representing an incoming voltage Vin that is used to power one or more appliances 230. The analyzing unit 410 further comprises a current terminal 220 for receiving a signal l_tot representing a total current I in as provided to the appliances 230 and an output terminal 405 comprising a PLC transmitter for providing a control signal to a power grid (i.e. the electrical wiring connecting the incoming voltage Vin to the appliances 230) powering the plurality of appliances;

The analyzing unit 410 further comprises a processing unit 440 arranged to:

o receive the current signal l_tot and the voltage signal Vin;

o obtain an identification of the plurality of appliances;

o determine a power consumption of the identified plurality of

appliances based on the current signal and the voltage signal;

o determine a control signal for controlling an operating state of at least one of the plurality of appliances, the control signal including an identifier of the at least one of the plurality of appliances, and o providing the control signal to the PLC transmitter 405 for

transmission to the plurality of appliances.

In accordance with the present invention, the processing unit of the apparatus, is arranged to obtain an identification of the one or more appliances 230 that are powered.

As mentioned above, such an identification can be established from an analysis of the current

I in that is supplied to the appliances. Alternatively, a polling signal 415 can be provided by the PLC transmitter of the output terminal 405 to the power grid for probing the appliances that are powered. Any appliances equipped to handle PCL commands may then, in reply to the polling signal, provide a reply signal containing an identification of the appliance. In order to receive the reply signal, the output terminal 405 should be equipped with a PLC receiver as well, or should be a PLC transceiver. The polling signal 415 can be provided by the processing unit 440 to the output terminal 405 via connection 406, which can be a wired or wireless connection.

In accordance with the present invention, an operating state of one or more of the appliances is controlled by the processing unit, by providing a control signal to the appliances, using the PLC transmitter 405. By doing so, appliances that are capable of receiving and processing PLC commands, may be controlled.

Note that the processing unit 440 need not be located on site or near the electrical grid, the processing unit can e.g. be located remotely, whereby voltage and current signals of several customers can be processed. In such arrangement, the processing unit can e.g. make use of a (central) database for determining the optimal voltage for a given set of appliances or estimating the power consumption at the optimal supply voltage.

In an embodiment, as shown in Figure 4, the processing unit 440 can provide a signal 460 representing the difference to a user interface or webpage 470, thus enabling the customer to become informed of a potential saving in energy. Such energy savings can e.g. be estimated by integrating the determined difference over time.

In an embodiment, the apparatus may further comprise a terminal for receiving an occupancy signal. Such an embodiment is schematically shown in Figure 5. As can be seen, the apparatus as schematically shown in Figure 5 has a similar structure as the apparatus shown in Figure 4, including an analyzing unit 610 and a processing unit 640. The analyzing unit 610 comprises input terminals 220 and 420 for receiving voltage and current signals in order to analyze the load 230 (i.e. one or more appliances that are powered) by the processing unit

640. As can be seen, signals representing the voltage Vin and the total current I in to the one or more appliances 230 are provided to the analyzing unit. As an alternative to providing the voltage signal Vin, the analyzing unit may also be provided with a signal representing the total consumed power by the one or more appliances.

As can be seen, the apparatus further comprises an input terminal 650 for receiving an occupancy signal 655 indicating an occupancy of the household or office of the customer, as discussed above. In accordance with the invention, the processing unit 640 of the apparatus is arranged to:

- receive the current signal (l_tot) and the voltage signal Vin;

- obtain an identification of the appliances by analyzing the current signal or by polling the power grid (using the PLC transmitter 405), in a similar manner as explained above; and - determine a power consumption of the identified one or more appliances based on the current signal and the voltage signal;

- assess a necessity of the power consumption of the identified one or more appliances based on the occupancy signal;

- determine a minimized power consumption of the one or more appliances based on the necessity.

In an embodiment, the processing unit 640 is further arranged to output an output signal 660 (at an output terminal 665) representing a difference between the power consumption and the minimized power consumption to a user interface 670 or the like.

Such a user interface (which may also take the form of a webpage accessible to the customer) may thus provide the user with insight in the power consumption of the appliances 230.

In such embodiment, the processing unit may further be equipped to provide an inquiry to a customer or user requesting an authorization for controlling the operating state of an appliance. Such an inquiry can be provided to the customer via electronic messaging or the like. In order to output such a request or inquiry, the output terminal 665 of the analyzing unit 610 or a further output terminal (not shown) can be used. Such an inquiry may further include information regarding the potential energy savings when the request to alter an operating state is authorized.

In an embodiment, the processing unit 640 is further arranged to provide a ranking or selection of the appliances most suited for active control by remotely controllable electrical switches. Such a selection or ranking can be based on the potential energy savings that can be made when the selected appliances would be powered in accordance with the necessity. When the processing unit has thus identified one or more of the identified appliances as suitable candidates for the application of an active control of the power consumption this information can be provided to the customer. Such an identification can e.g. be based on the determined necessity of the power consumption of the appliances and/or on the amount of power consumed.

In order to establish such an active control, the apparatus according to the invention comprises, in an embodiment, one or more remotely controllable switches for installation at a selected of appliances, the selection being determined by the processing unit 640 and based on the necessity and optionally on the power consumption of the appliances. With respect to the latter, a ranking in terms of energy savings can be made of the appliances that are powered whereby the potential energy savings (obtainable by actively controlling the power consumption based on the necessity) will be larger when:

the appliance is powered at unnecessary instances or periods (i.e. having a low necessity, given the occupancy situation);

the appliance has a comparatively large power consumption.

As such, in an embodiment, the processing unit is arranged to determine a selection of the appliances for active control, based on both the necessity and the relative power consumption of the appliances.

An embodiment of the apparatus according to the invention including remotely controllable electronic switches is schematically shown in Figure 6.

Compared to the apparatus shown in Figures 4 or 5 , the apparatus as shown in Figure 6 further comprises remotely controllable electrical switches 680.2 - 680.3 for controlling a power consumption of resp. appliances 230.2 - 230. 3 of the load 230. In an embodiment, the controllable switches 680.2 - 680.3 comprise a switch for interrupting the power supply to the resp. appliances, whereby an operation or operating state of the switch can be controlled by a control signal which is provided to a receiver (e.g. a PLC receiver) of the remotely controllable electrical switch by the PLC transmitter 605. In the embodiment as shown, the remotely controllable switches are only applied for a selected set of appliances that are not equipped to receive and process PLC signals. In the embodiment as shown, appliance 230.1 is assumed to be equipped to receive and process PLC control signals, therefore no switch is required to control an operating state of the appliance 230.1 , rather, the appliance can be readily controlled by the PLC transmitter (or transceiver) 605.

Since the apparatus according to the invention as described enables an identification of the appliances that are powered and enables an active control of the power consumption (by controlling the operating state) of an appliance, the apparatus according to the invention may further be arranged to control the power consumption such that certain constraints are met. Such constraints can e.g. be a maximum value of the total consumed power by the customer. In case such a constraint is provide, e.g. via a user interface to the analyzing unit, such as unit 610, which provides the constraint to the processing unit 640, the processing unit can determine a power schedule for powering the appliances, whereby the constraint is met, as much as possible. In order to establish such a scheme, use can be made of the identification of the different loads or appliances, of the occupancy signal being indicative of the necessity of certain appliances at certain instances and of the controllable electrical switches.

In an embodiment, schematically shown in Figure 7, the apparatus may further comprises a voltage adjustment unit 250. The analyzing unit 210 comprises a current input terminal 220 for receiving an input signal l_tot representing a total current I in supplied to one or more appliances 230. The analyzing unit 210 further comprises a processing unit 240 for processing the input signal l_tot. The processing unit 240, which can e.g. comprise one or more processors or microcontrollers or the like, is arranged to receive, the input signal l_tot and analyze the input signal to obtain an identification of the one or more appliances 230 or obtain an identification using the polling procedure as explained above. The processing unit 240 is further arranged to determining an optimal supply voltage based on the identification and the power consumption and output a control signal 260 representing the optimal supply voltage to a signal input terminal 270 of the voltage control unit 250. Using the control signal 260, the voltage control unit 250 may then control a voltage adjustment circuit 300 of the voltage control unit 250 in order to obtain a supply voltage 290 that is better suited, i.e.

substantially corresponds to the optimal supply voltage. In order to do so, the voltage adjustment circuit 300 can e.g. comprise a variable transformer.

In an embodiment, the control signal 260 as provided to the voltage control unit may equally comprise information regarding the identified appliances that are powered. This information can e.g. be useful to perform further adjustments to the supply voltage. Examples of such adjustments are e.g. the filtering of harmonic component which may be caused by particular loads or appliances or the balancing of phases in case the incoming voltage Vin and the supply voltage Vsup are three-phase voltages.

In an embodiment, the apparatus according to the invention (comprising the voltage control unit and the analyzing unit) can operate as a stand-alone unit which can e.g. be mounted in an electrical cabinet of a customer such as a household or small office. In such embodiment, the analyzing unit, or in particular the processing unit 240 of the analyzing unit can be provided with a database containing particular power characteristics of known appliances (or commonly used appliances), such characteristics also being referred to as fingerprints or signatures, to perform the step of identifying the load 230 that is powered. The analyzing step may be performed by the processing unit in two stages; a first stage aiming at identifying which appliances are connected to an electric network of a customer and a second stage aimed at identifying which appliances are powered at a particular instance or within a particular time frame.

The first stage can e.g. be performed upon installation of the apparatus whereby the power consumption is monitored, via the total current, for a considerable period of time (which can e.g. take several days) to assess which apparatuses are present. Note that during such comparatively long monitoring period, various combinations of load will have occurred, thus facilitating the disaggregation of the load in different components. Once the available load are known, a given combined load of a plurality of appliances can more easily, and thus more rapidly by identified.

As an alternative to the stand-alone embodiment, the processing of the total current to obtain the identification and the determination of the optimal supply voltage can be performed remotely, at a central analyzing or processing unit which can be shared by a large number of customers. In such arrangement, the total current signal l_tot can e.g. be provided via a wireless network such wifi or the like to the central processing unit, the control signal for controlling the voltage adjustment circuit can be provided to the voltage control circuit in a similar manner.

In such arrangement, maintenance of a database containing fingerprints or signatures of appliances is facilitated.

In the different embodiments of the apparatus according to the invention, the total current l_tot can be supplied to the processing unit at regular intervals, e.g. every minute or every 5 minutes, enabling a comparatively fast adjustment of the supply voltage to changes in either the load situation or changes of the incoming voltage. Alternatively, or in addition, the total current signal can be supplied to the processing unit when a change in the total current is detected.

In an embodiment of the apparatuses according to the invention as described above, the processing unit can further be equipped to calculate energy savings that have been made due to the control of an operating state or an adjustment of the supply voltage.

With respect to the latter, the processing unit may monitor the incoming voltage, determine or estimate the power consumption of the identified appliances if they were powered by the incoming voltage (instead of being powered by the optimal supply voltage) and compare this with the actual power consumption. Integrating the difference between the actual power consumption and the estimated power consumption (when powered by the incoming voltage) over time provides an indication of the energy savings.

Similarly, when an operating state of one or more appliances is adjusted (e.g. an appliance is turned off), the energy savings can be determined by integrating the difference in power consumption over time.

In an embodiment, the processing unit of the apparatus according to the invention to output a signal (e.g. via an output terminal of the analyzing unit) or a separate terminal representing the savings made.

In a preferred embodiment, the information on the saving can be made available to a user via near field communication (NFC). Alternatively or in addition, the information can be communicated at regular intervals (e.g. each day) to a customer via electronic messaging, or made available for consulting via a webpage.

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention.

The terms "a" or "an", as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language, not excluding other elements or steps). Any reference signs in the claims should not be construed as limiting the scope of the claims or the invention.

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.

The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.

A single processor or other unit may fulfil the functions of several items recited in the claims.