EP4251461A1

EP4251461A1 - Controlling the charging of electric vehicles

Info

Publication number: EP4251461A1
Application number: EP21815579.4A
Authority: EP
Inventors: Simon Jonathan HUGHES
Original assignee: Zpn Soft Ltd
Current assignee: Larkfleet Smart Homes Ltd
Priority date: 2020-11-23
Filing date: 2021-11-16
Publication date: 2023-10-04
Also published as: WO2022106802A1; GB2601308B; GB202308116D0; GB202018392D0; GB2615959A; GB2601308A

Abstract

The charging of electric vehicles (121, 122) from a domestic electricity supply (117) is shown, in which a grid-connected source (117) supplies electricity to a plurality of dwellings (102, 103), with each dwelling having a charging outlet for charging an electric vehicle. A power management apparatus (201) is provided along with control units (211, 212). The power management apparatus establishes a weekly schedule (603, 604) for each dwelling, consisting of contiguous intervals (801) of less than one hour during which a respective control unit may permit the charging of an electric vehicle or is forced to inhibit the charging of the electric vehicle. The power management apparatus transmits respective schedule data, derived from an established weekly schedule, to each dwelling. Each control unit (211) is connected between the grid connected source (117) and a respective one of the charging outlets (1001). Each control unit receives the schedule data and stores this schedule data to re-establish a local copy of the weekly schedule for the respective dwelling, with any previously stored schedule being replaced. Thereafter, the control unit operates switches (1111, 1112, 1113) to permit the charging of an electric vehicle or inhibit the charging of the electric vehicle in accordance with the respective locally stored weekly schedule.

Description

Controlling the Charging of Electric Vehicles

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from United Kingdom patent application number 2018392.7, filed on November 23^rd, 2020, the whole contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a system for controlling the charging of electric vehicles from a domestic electricity supply, of the type in which a grid- connected source supplies electricity to a plurality of dwellings and each said dwelling has a charging outlet for charging an electric vehicle, comprising a power management apparatus and a plurality of control units.

The present invention also relates to a method of controlling the charging of electric vehicles from a domestic electricity supply, of the type in which a grid-connected source supplies electricity to a plurality of dwellings and each said dwelling has a charging outlet for charging an electric vehicle.

A system for controlling the charging of electric vehicles from a domestic electricity supply is disclosed in EP 3068005. A grid-connected source is shown that supplies electricity to dwellings, wherein each dwelling has a charging outlet for charging an electric vehicle. Each dwelling has a control unit, identified as a home energy management system.

The disclosed dwelling includes a distribution board that supplies power, received from the grid-connected source, to domestic loads in the house or to the vehicle via the charging outlet. The distribution board is provided with a power sensor that measures each of the power received from the grid-connected source, the power supplied to the load and the power supplied to the vehicle. These measured values of power are supplied to the control unit. The distribution board has a control switch that is controlled by the control unit for feeding or interrupting power to the load and to the vehicle. Thus, the distribution board is controlled by the control unit to control the feeding and interruption of power to the load and to the vehicle. The distribution board may also have a breaker that can interrupt the reception of power from the grid.

The document describes how the control unit monitors the power supplied to the load and to the vehicle and displays the amounts of power feeding the load and feeding the vehicle. In addition, the control unit controls the power supplied to the load and to the vehicle. Furthermore, the control unit can communicate with an electric power provider that manages the system power supply to receive information identified as a 'demand response'. Based on this received information, the control unit can independently identify times during which a vehicle can be charged and identify times during which the charging of a vehicle is inhibited.

The document identifies demand response as referring to a mechanism by which a consumer of electricity changes the demanded amount to keep supply and demand for electricity in balance. Demand response is provided to reduce the load based on a contract with the electric power provider or to allow a consumer to adjust the demand amount based on the electricity rate system provided by the electric power provider.

Thus, initial constraints are established, based on the contract between the electric power provider and the consumer. Thereafter, further demand response data may be received from the electricity provider creating further constraints. However, at all other times, the local control unit (home energy management system) is autonomous and responsible for locally generating its own charging schedule. Such a situation may be acceptable when the number of systems present within a network is relatively small. However, as the number of deployed installations within a network increase, the overall response of the system can become complex and ultimately chaotic.

A problem therefore exists in terms of restricting the way in which the control units may operate without increasing complexity and while still allowing the apparatus to operate pseudo-autonomously during times when communication with a power management apparatus is not necessary or, usually for communication reasons, is not possible. The present invention seeks to overcome these problems. BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a system for controlling the charging of electric vehicles from a domestic electricity supply of the aforesaid type, characterized in that: the power management apparatus is configured to: establish a schedule for each said dwelling, consisting of contiguous intervals of less than one hour during which a respective control unit may permit the charging of an electric vehicle or is forced to inhibit the charging of an electric vehicle; and transmit respective schedule data, derived from a said established schedule, to each said dwelling; each said control unit is connected between the grid-connected source and a respective charging outlet; and each said control unit is configured to: receive the schedule data; store said schedule data , wherein any previously stored schedule data is replaced; and operate switches to permit the charging of an electric vehicle or inhibit the charging of an electric vehicle in accordance with the respective locally stored schedule data.

Thus, in accordance with the invention, the autonomous nature of the control units is restricted and it is only possible for them to operate in accordance with a schedule received from the power management apparatus. As such, the processing requirement of the control units is reduced, along with their overall complexity. It is not necessary for the control units to receive data from the power management apparatus relating to overall demand. Should a demand issue arise, problems can be resolved by the mechanism of transmitting a revised schedule. Thus, upon receiving a revised schedule, the old schedule is overwritten. However, the schedule will remain in place and operation will continue in a pseudo-autonomous manner until new schedule data is downloaded. It is not necessary to measure power consumption locally and it is not necessary to measure total power output from the grid. Furthermore, it is not necessary to monitor power consumed by other electrical equipment.

According to a second aspect of the present invention, there is provided a method of controlling the charging of electric vehicles from a domestic electricity supply, of the aforesaid type, characterized by the steps of: establishing a schedule for each dwelling at a power management apparatus, wherein said schedules comprise contiguous intervals of less than one hour; producing schedule data for each said dwelling; transmitting said schedule data from the power management apparatus to respective control units, wherein each said control unit is connected between the grid-connected source and a respective one of said charging outlets; receiving transmitted schedule data at each control unit; storing received schedule data at each control unit , wherein any previously received schedule data is replaced; and operating each control unit in accordance with its stored schedule data to permit the charging of an electric vehicle or to inhibit the charging of an electric vehicle.

The duration of the contiguous intervals may change but, in an embodiment, the contiguous intervals are of a substantially similar duration. In an embodiment, the contiguous intervals have a duration of between five minutes and thirty minutes. In an embodiment, the schedule is interrogated during each interval to determine whether charging is to be permitted or inhibited.

In an embodiment, the operating step continues to repeat the stored schedule data, possibly on a weekly basis. Thus, it is not necessary, in an embodiment, for new schedule data to be downloaded . The schedule is repeated until new data overwrites the schedule data previously stored.

In an embodiment, data is stored identifying when a control unit has been operated to permit charging. This data may be returned back to the power management apparatus confirming that operation is taking place in an intended way. Alternatively, appropriate action can be taken.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Figure 1 shows an estate of domestic dwellings;

Figure 2 shows part of a system for controlling the charging of electric vehicles from a domestic electricity supply; Figure 3 shows operations performed by the system shown in Figure 2;

Figure 4 shows an example of a power management apparatus, including a processor;

Figure 5 shows operations performed by the processor identified in Figure 4;

Figure 6 shows an example of a schedule generated by the apparatus shown in Figure 4;

Figure 7 shows alternative schedules;

Figure 8 shows a further alternative schedule;

Figure 9 illustrates the production of schedule data;

Figure 10 shows an example of a control unit;

Figure 11 shows a schematic representation of the control unit identified in Figure 10;

Figure 12 shows an example of procedures performed by the processor contained within each control unit;

Figure 13 shows an example of procedures performed by the processor contained within the power management apparatus; and

Figure 14 illustrates the uploading of usage data.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Figure 1

Domestic dwellings 101 to 116 are shown in Figure 1 and may collectively be referred to as an estate. The estate receives electrical energy from a grid-connected source 117, the operation of which may be overseen (in the United Kingdom) by a distributed network operator (DNO).

The grid -connected source 117 supplies electrical energy to the dwellings 101 to 116 within predetermined constraints of an individual maximum power level to each dwelling and a total maximum power level for the estate. Each dwelling may receive a domestic supply of electrical energy from the grid-connected source 117 up to the individual maximum power level.

Some of the occupants own electric vehicles and will wish to recharge these vehicles from their domestic supply. In the example, electric vehicles 121 to 132 are shown such that a plurality of the dwellings (102, 103, 104, 106, 107, 109, 110, 111, 112, 113, 115 and 116) take electrical energy from the grid-connected source 117 for the purpose of vehicle recharging.

Figure 2

An embodiment of the invention provides a system for controlling the charging of electric vehicles from a domestic electricity supply, in which a grid- connected source supplies electricity to a plurality of dwellings (as listed above) and each dwelling has a charging outlet for charging an electric vehicle. Part of the overall system is illustrated in Figure 2, with dwelling 102 being shown along with dwelling 103; although the complete system includes all dwellings that have a respective vehicle under charge. The system is provided with a power management apparatus 201 and a plurality of control units. This includes a first control unit 211 and a second control unit 212, along with similar control units provided for each vehicle under charge (123 to 132).

Each dwelling (102, 103) is connected to the Internet 241 and communication within the environment of each dwelling is achieved using well- established wireless protocols. Thus, Internet communication with each control unit is achieved by a wireless connection between the control unit (211 ) and its respective dwelling (102) via a respective antenna, such as a first antenna 251 and a second antenna 252. In this way, it is possible for data to be downloaded from the power management apparatus 201 to each of the control units 211, 212 etc. In addition, it is possible for data to be uploaded from the control units to the power management apparatus 201.

Figure 3

Operation of the system described with reference to Figure 2 is illustrated in Figure 3. At step 301 schedule data is created for each of the control units within the system. Thereafter, at step 302, the schedule data is uploaded to the control units. Thus, if the control units already have schedule data stored therein, this data is replaced and updated with the new schedule. Thereafter, at step 303, the control units operate in accordance with the schedule data that they have received. To achieve the operations described above, in an embodiment, the power management apparatus 201 is configured to establish a weekly schedule for each of the dwellings, consisting of contiguous intervals of less than one hour during which a respective control unit may permit the charging of an electric vehicle or is forced to inhibit the charging of an electric vehicle. In addition, the power management apparatus 201 is also configured to transmit respective schedule data, derived from an established weekly schedule, to each of the dwellings. As described with reference to Figure 2, each control unit (211 ) is connected between the grid connected source (117, via dwelling 102) and a respective charging outlet (connecting to vehicle 121). Each control unit is configured to receive schedule data and store this schedule data; with any previously stored schedule data being replaced. Thereafter switches are operated (as described with reference to Figure 11 ) to permit the charging of an electric vehicle or to inhibit the charging of an electric vehicle in accordance with the respective locally stored weekly schedule.

In an alternative embodiment, schedule data is produced on a daily basis and new schedule data is downloaded each day. An advantage of this approach is that it reduces the data storage requirement of each control unit. Furthermore, regular contact is maintained between the power management apparatus and each control unit within the system.

Figure 4

An example of a power management apparatus is shown in Figure 4 and includes a processor 401 that communicates with input devices and a graphical display 402. The graphical display 402 presents a graphical user interface 403 to an operative to facilitate the establishment of schedules, possibly created on a daily basis or on a weekly basis.. Furthermore, the processor 401 communicates with a first database 404 and a second database 405. An Internet connection 406 provides a connection to the Internet 241 to facilitate communication between the power management apparatus and the individual control units.

Within the graphical user interface 403, a specific control unit may be identified in a first region 411. A first column 412 allows time intervals to be specified and for each specified time interval, a second column 413 allows entries to be made to state whether charging is possible or whether charging is to be inhibited.

After establishing a schedule for a dwelling, the processor 401 writes details to the first database 404 from which schedule data can be derived for transmission to a respective control unit. In an embodiment, data is also uploaded from individual control units, confirming that charging has been enabled or that charging has actually taken place. This uploaded data from the control units is then written to the second database 405. This data may also be conveyed to a higher-level system director for coordinating the activities of many estates of the type described with reference to Figure 1 .

Figure 5

Operations performed by the processor 401 are detailed in Figure 5. At step 501, a weekly schedule is established which, in an embodiment, involves interacting with the graphical user interface 403. Thus, the established weekly schedule may at this stage be considered as something that can be presented to an operative and, possibly, to a customer during an interactive session of schedule establishment.

At step 502, the established weekly schedule is processed to produce schedule data. In this embodiment, it is the schedule data produced at step 502 that is written to the first database 404 at step 503. Thereafter, at step 504 a question is asked as to whether a further schedule is to be established and when answered in the affirmative, the next weekly schedule is established at step 501.

Figure 6

In an embodiment, it is possible for schedules to be created based purely on technical constraints. Thus, if a significant amount of electrical energy is available, each schedule may include many slots during which charging is made possible. As demand increases, schedules could be amended to inhibit the charging of electric vehicles at certain times during the day. Thus, charging could be prevented when there is a significantly high demand for electricity for other purposes and, in addition, electric vehicle charging periods may be rationed to some extent such that, for example, during the first half of each charging hour a first set of vehicles may charge followed by a second set of vehicles being charged during the second half of each charging hour. However, in an embodiment, it is envisaged that contractual relationships with a customer would be agreed for the provision of electricity for charging an electric vehicle and once agreed, a weekly schedule could be presented to a user by means of the graphical user interface.

Having defined a schedule on a weekly basis, the schedule data may reflect this and contain data for a whole week. Alternatively, from the weekly schedule, schedule data may be transmitted on a daily basis. This approach allows changes to be made on a daily basis, should this become necessary due to an unusual event creating greater demand or due to a technical issue. It does involve greater levels of data communication but the actual data volume is very small compared to other typical internet activities within the environment.

An example of a graphical user interface is illustrated in Figure 6. A specific user is identified at 601 which in turn relates to a specific control unit (say control unit 211). A service type is identified at 602 which, for example, could be a standard service, an enhanced service or a priority service. As described with reference to Figure 7, it is also possible for an emergency schedule to be established for use when electricity supply problems occur. It is likely that most customers would sign-up for the standard service. The enhanced service would require an additional fee and the priority service would only be made available to those with specific needs.

In the example shown in Figure 6, the weekly schedule is divided into a midweek schedule 603 and a weekend schedule 604. Thus, the midweek schedule 603 represents a midweek day (Monday to Friday) with the weekend schedule 604 representing a weekend day of Saturday or Sunday. Each day is then divided into contiguous intervals of less than one hour. The intervals are contiguous to ensure that there are no times during which the availability of charge is ambiguous. The actual length of the intervals could vary but, in an embodiment, the contiguous intervals are of a substantially similar duration. The contiguous intervals may have a duration of between five minutes and thirty minutes. In the embodiment shown in Figure 6, contiguous intervals have a duration of thirty minutes, such that forty-eight intervals of equal duration are present within each twenty-four-hour day. Thus, in this way, it is possible for the schedule to be interrogated during each interval to determine whether charging is to be permitted or inhibited.

In the embodiment of Figure 6, shaded regions, such as a first shaded region 611, a second shaded region 612, a third shaded region 613 and a fourth shaded region 614 represent intervals during which electric vehicle charging is permitted. Similarly, the unshaded regions, such as a first unshaded region 621 , a second unshaded region 622 and a third unshaded region 623 represent intervals during which the charging of electric vehicles is inhibited.

In an embodiment, when producing this schedule, it is possible, within the graphical user interface, for an operative to “mouse over” the region in order to change an interval from an interval during which charging is not permitted to an interval during which charging is permitted. In an alternative embodiment, mouse clicking of individual interval regions may be required.

In accordance with this standard service type, charging is permitted from midnight to 7.00am, then from 10.00am to 12.00 noon, from 2.00pm to 4.00pm and then from 10.00pm to 12.00 midnight. At other times, charging is not permitted.

Again, in accordance with this standard service type, the availability of charging periods over the weekend is more restricted. As shown in Figure 6, charging is allowed overnight from midnight until 8.00pm (whereas it is only allowed until 7.00am during weekdays). However, for most of the day, charging is not possible and only becomes possible again after 11.00pm.

An example of an enhanced service type may provide for the charging of the electric vehicle at times between 8.00am and 11.00pm over the weekend.

In an embodiment, it is also possible to modify the weekly schedule in response to anticipated events that are expected to increase electricity demand. Thus, at any time, it is possible to establish a revised weekly schedule for one or more of the deployed control units and then download modified schedule data to the control units. Upon receiving a new schedule, the control units will adopt this by overwriting the previous schedule data. A modified schedule could be produced for a particular day or days within a particular week. Thereafter, the normal schedule would be sent again and activity would continue as before.

In the example of Figure 6, charging is permitted between 2.00pm and 4.00pm during midweek days. The network operator may be aware that an event will take place on a Wednesday afternoon during which it would be preferable for vehicle charging to be inhibited. Thus, a modified schedule is produced that removes the third charging region 613 such that, over this particular week, charging is not possible between 12.00 noon and 10.00pm.

Figure 7

An example of a priority schedule is shown at 701. The schedule is identified as a priority schedule at 702 and a first charging region 701 is similar to region 611, allowing charging between 12.00 midnight and 7.00am. Similarly, a second region 702 permits charging between 10.00am and 12.00 noon, as does region 612. However, a third region 703 allows charging between 2.00pm and 12.00 midnight whereas, for the standard charging schedule, charging would not be possible between 4.00pm and 10.00pm, as indicated by region 623.

An emergency schedule 721 is also shown in Figure 7. Schedules of this type would only be established very rarely if ever. However, it is possible that a problem may occur in terms of electricity generation. To conserve the available electricity for essential purposes, virtually no charging of electric vehicles is allowed. In this example, to ensure that the batteries of electric vehicles do not become totally discharged, charging is permitted between 11.00pm and 12.00 midnight, as indicated by charging region 722. In an embodiment, differently positioned charging regions of a similar duration would be sent to different control units, thereby spreading the recharging burden over the day. Thus, in accordance with this embodiment, it is possible to establish a weekly schedule that comprises establishing a modified schedule in response to an unexpected reduction in available electricity.

Figure 8

The examples of weekly schedules, described with reference to Figure 6 and Figure 7, provide contiguous intervals that have a duration of thirty minutes. As previously described, the contiguous intervals may have any duration and an embodiment may allow adjustment between intervals of five minutes and intervals of thirty minutes.

In the example shown in Figure 8, each interval, such as unshaded interval 801, has a duration of fifteen minutes. As can be seen in Figure 8, between 9.00am and 10.00am there are four programmable intervals. A charging region 802 has been defined which will allow charging to take place from 10:15 to 12:30.

Figure 9

As described with reference to Figure 5, in an embodiment, a weekly schedule, of the type described with reference to Figure 6, is established at step 501 whereafter, at step 502, schedule data is produced. An example of the production of this schedule data is illustrated in Figure 9.

Following step 501, in this example, a midweek schedule 603 has been produced along with a weekend schedule 604. Processor 401 converts the weekly schedule to schedule data 901 and writes this schedule data to the first database 404, such that the schedule data is then available to be downloaded to a respective control unit.

The schedule data 901 identifies contiguous charging intervals over a full seven-day weekly period. Thus, in this embodiment, the schedule data may consist of a first portion 911 for Monday, a second portion 912 for Tuesday, a third portion 913 for Wednesday, a fourth portion 914 for Thursday, a fifth portion 915 for Friday, a sixth portion 916 for Saturday and a seventh portion 917 for Sunday. Thus, each day of the week is specified for the control units, with each day having its own contiguous intervals.

If required, it would be possible to create weekly schedules for specific days of the week, given that, when the week is divided into a midweek portion and a weekend portion, as described with reference to Figure 6, the actual downloadable schedule data is constructed to provide a schedule for each individual day of the week. At the relevant control unit, data for each day are then read cyclically until the system is decommissioned or the control unit receives updated data, as described with reference to Figure 7.

In an alternative embodiment, schedule data is downloaded on a daily basis. Thus, for example, schedule data 911 would be downloaded on Monday, schedule data 912 would be downloaded on Tuesday and so on.

Figure 10

An example of a control unit 211 is shown in Figure 10, connected between a grid-connected source and a charging outlet 1001. The charging outlet 1001 may be a dedicated unit installed for the purpose of charging an electric vehicle. Alternatively, a vehicle battery charger 1002, of the type usually supplied with an electric vehicle, may be connected to the charging outlet 1001.

In an embodiment, the control unit includes mechanical attachments 1003 for securing the control unit at a position between a domestic distribution consumer unit, which is in turn connected to the grid-connected source, and the charging outlet 1001.

Figure 11

A schematic representation of the control unit 211 is shown in Figure 11. The control unit includes a communication device 1101 which, as previously described, may establish radio communication within the environment of the dwelling. This in turn provides communication via the Internet to the power management apparatus 201 , allowing schedule data to be downloaded and data relating to confirmation of use to be uploaded.

A switching device 1102 selectively connects the grid connected source to the charging outlet. A processor 1103 determines whether the electrical output can be activated to supply electricity to the charging outlet by making reference to the schedule data. Thus, the processor 1103 selectively activates a switching device 1102 in accordance with the respective locally stored weekly schedule data.

In an embodiment, schedule data, received from the power management apparatus, are stored locally in a local database 1104 that is in communication with the processor 1103. Furthermore, the database 1104, or an alternative database, may provide a storage device for storing output data identifying when the grid-connected source is actually connected to the charging outlet.

In an embodiment, the switching device 1102 comprises a plurality of cascaded relays. In the embodiment illustrated in Figure 11 , three cascaded relays are provided, comprising a first relay 1111, a second relay 1112 and a third relay 1113. Electricity from the grid-connected source is supplied directly to the third relay 1113 over a powerline 1114.

The processor 1103 includes an output port 1115 configured to supply a relatively low voltage control signal to the first relay 1111. The first relay 1111 and the second relay 1112 receive power from a local power supply 1116 at appropriate voltages derived from the grid. Activation of the first relay 1111 results in the activation of the second relay 1112, effectively amplifying the level of the control signal, such that sufficient power is provided to activate the third relay 1113.

In an embodiment, a Hall effect detector 1117 monitors current flowing to control the third relay 1113, thereby providing output data specifying that the third relay has been activated, thereby confirming that power has been made available to the charging outlet.

Figure 12

Procedures performed by the processor 1103 contained within each control unit, to facilitate the updating of the control unit, and described with reference to Figure 3, are detailed in Figure 12.

Upon installing a new control unit at a specific dwelling location, it is necessary to perform a degree of commissioning. Firstly, it is necessary to establish communication within the radio network of the dwelling to ensure that it is possible for the control unit to establish communication with the power management apparatus 201 via the Internet 241. However, it should also be appreciated that if this communication channel is lost, but schedule data has been downloaded, the running of this schedule will continue and the charging of electric vehicles will remain possible. Thus, upon first start-up, a question is asked at step 1201 as to whether the local schedule has been updated. During the commissioning process, this question will be answered in the negative and it will then become necessary to generate an interrupt signal back to the power management apparatus 201, as described with reference to Figure 13. Thus, at step 1203 the schedule is downloaded and the updating process 302 will have been completed.

Having received schedule data, the control unit is now in a position to operate as illustrated at 303. In this embodiment, a real-time clock generates an interrupt at step 1204 resulting in the schedule being read at step 1205. Thus, for example, a clock interrupt may be generated shortly after 4.00am on a Monday. Assuming schedule data has been downloaded, a status is determined given that charging is possible between 4.00am and 4.30. Thus, an activation is either initiated or maintained at step 1207 followed by the activity being logged at step 1208 in response to the output from the Hall effect device 1117.

At step 1209, a question is asked as to whether the process is to end and when answered in the negative, the process waits for the next clock interrupt at step 1204.

As shown in Figure 12, in response to the determination made at step 1206, an activation or deactivation may occur at step 1207. Although deactivations tend not to create any problems, a problem may occur when many control units within the overall system attempt to perform an activation at the same time. When such a situation occurs, this creates a surge condition with respect to the grid connected source which may in turn cause the source to fail. Thus, in an embodiment, it is possible to introduce a random delay between the status determination step 1206 and the actual activation performed at step 1207. With this random delay being different at different control units within the system, individual control units will activate at different times thereby avoiding the previously described surge condition.

Figure 13

Procedures performed by processor 406, within the power management apparatus, for implementing the updating of control units, as described with reference to Figure 3, are detailed in Figure 13. At step 1301, processor 406 receives the control unit interrupt generated at step 1202. At step 1302 the control unit is identified and a question is then asked at step 1303 as to whether a schedule is available. When answered in the affirmative, the schedule data is downloaded from database 404 to database 1104 of the relevant control unit.

Alternatively, the question asked at step 1303 may be answered in the negative, to the effect that schedule data is not available. Under these circumstances, an error message may be generated which in turn may prompt further investigation. Alternatively, in the embodiment shown in Figure 13, it may be possible to create a default schedule at step 1305, which is then downloaded at step 1306. This may be followed by the generation of a message at step 1307 to the effect that a default schedule has been downloaded and the process then closes at step 1308.

Figure 14

The procedures performed by the power management apparatus, as described with reference Figure 13, and the procedures performed by each control unit, as described with reference to Figure 12, facilitate the establishment of a method of controlling the charging of electric vehicles from a domestic electricity supply, in which a grid connected source supplies electricity to a plurality of dwellings and each dwelling has a charging outlet for charging an electric vehicle. The method establishes a schedule for each dwelling at a power management apparatus, with the schedules comprising contiguous intervals of less than an hour, as described with reference to Figure 6.

Schedule data is produced for each dwelling, as described with reference to Figure 9. The schedule data is then transmitted from the power management apparatus to respective control units, wherein each control unit is connected between the grid-connected source and a respective one of the charging outlets. At each control unit, transmitted schedule data is received and stored, with any previously received schedule data being replaced. Each control unit is then in a position to operate in accordance with its respective schedule to permit the charging of an electric vehicle or to inhibit the charging of the electric vehicle. In an embodiment, this operating step continues to repeat the stored schedule until being updated.

In an embodiment, the control units store data identifying when a control unit has been operated to permit charging. In the described embodiment, this data is stored locally within a database 1104. In addition, as illustrated in Figure 14, individual control units, identified as a first control unit 1401 to a twelfth control unit 1412, periodically upload this stored data back to the power management apparatus 201.

Options exist in terms of how often the downloading of schedule data is required. Daily schedule data downloads increase flexibility and reduce storage requirements. It is also possible to allow control units to operate in a pseudo-autonomous way, such that continual data communication is not necessary. However, given the abundance of data capacity within most dwellings, are regular heartbeat or “ping” may be maintained with each control unit possibly every thirty minutes. In this way, an operator maintains control of power consumption and can arrange for the downloading of a new daily schedule within each thirty-minute window.

Claims

CLAIMS The invention claimed is:

1. A system for controlling the charging of electric vehicles from a domestic electricity supply, in which a grid-connected source supplies electricity to a plurality of dwellings and each said dwelling has a charging outlet for charging an electric vehicle, comprising: a power management apparatus; and a plurality of control units, characterized in that: said power management apparatus is configured to: establish a schedule for each said dwelling, consisting of contiguous intervals of less than one hour during which a respective control unit may permit the charging of an electric vehicle or is forced to inhibit the charging of an electric vehicle; and transmit respective schedule data, derived from a said established schedule, to each said dwelling; and each said control unit is connected between said grid-connected source a respective charging outlet; each said control unit is configured to: receive said schedule data; store said schedule data, wherein any previously stored schedule data is replaced; and operate switches to permit the charging of an electric vehicle or inhibit the charging of an electric vehicle in accordance with the respective locally stored schedule data.

2. The system of claim 1, characterized in that said power management apparatus includes a graphical user interface for receiving said schedules.

3. The system of claim 1, characterized in that said switches are implemented as cascaded relay devices.

4. The system of claim 1, characterized in that each control unit includes an additional storage device for recoding historical data relating to the operation of the respective control unit.

5. The system of claim 4, wherein each control unit includes a radio transmitter/receiver for receiving schedule data and transmitting said historical data.

6. A method of controlling the charging of electric vehicles from a domestic electricity supply, in which a grid-connected source supplies electricity to a plurality of dwellings and each said dwelling has a charging outlet for charging an electric vehicle, characterized by the steps of: establishing a schedule for each dwelling at a power management apparatus, wherein said schedules comprise contiguous intervals of less than one hour; producing schedule data for each said dwelling; transmitting said schedule data from the power management apparatus to respective control units, wherein each said control unit is connected between the grid-connected source and a respective one of said charging outlets; receiving transmitted schedule data at each control unit; storing received schedule data at each control unit, wherein any previously received schedule data is replaced; and operating each control unit in accordance with its stored schedule data to permit the charging of an electric vehicle or to inhibit the charging of an electric vehicle.

7. The method of claim 6, characterized in that said contiguous intervals are of a substantially similar duration.

8. The method of claim 7, characterized in that said contiguous intervals have a duration of between five minutes and thirty minutes.

9. The method of claim 8, characterized in that the schedule is interrogated during each said interval to determine whether charging is to be permitted or inhibited.

10. The method of claim 6, characterized in that: said schedule data defines a weekly schedule; and said operating step continues to repeat said stored weekly schedule.

11. The method of claim 6, characterized by storing data identifying when a control unit has been operated to permit charging.

12. The method of claim 6, characterized by the steps of: producing a command to inhibit charging in response to reading the local schedule data; calculating a random delay interval; and waiting for said random delay interval before de-activating the control unit to inhibit the charging of an electric vehicle.

13. The method of claim 6, characterized in that said step of establishing a schedule comprises the steps of: agreeing a contractual relationship with a customer for the provision of electricity for charging an electric vehicle; and recording the schedule via a graphical user interface.

14. The method of claim 13, characterized in that said step of establishing a schedule further comprises the steps of: establishing a weekly schedule; and 21 modifying said weekly schedule in response to anticipated events expected to increase electricity demand.

15. The method of claim 6, characterized in that said step of establishing a schedule comprises the step of establishing a modified schedule in response to an unexpected reduction in available electricity.