WO2008071995A2

WO2008071995A2 - Load balancing arrangement

Info

Publication number: WO2008071995A2
Application number: PCT/GB2007/004823
Authority: WO
Inventors: Rachel Elizabeth Cook; Simon William Saville Ambler; Alan Michael Parkin
Original assignee: Disenco Ltd
Priority date: 2006-12-14
Filing date: 2007-12-14
Publication date: 2008-06-19
Also published as: GB0624997D0; EP2102958A2; WO2008071995A3

Abstract

The invention provides an arrangement for use in an electrical power consumptio system associated with a local electrical generator (10) and an external electrical supply (11), the arrangement including electrical connections for at least two electrical appliances (12a, 12b) and a control unit (14) comprising a comparison device (14a) to compare the amounts of electrical consumption required by differe electrical appliances within the system and a power allocation device (14b) to allocate power from the local electrical generator (10) or the external mains suppl (11) to the electrical appliances according to specified priorities, and a user preference interface (15) to facilitate the input of user defined data into the power allocation device, whereby the control unit (14) can optimize usage of the power available from the local electrical generator (10), and when possible return power from the local electrical generator to the external electrical supply (11).

Description

Load Balancing Arrangement

Technical Field of the Invention

The invention relates to a load balancing arrangement to allocate electrical power in an electrical supply, generation and consumption system.

Background of the Invention

In electrical consumption systems having access to mains supply and local electrical generators, such as micro power generation units, it is desirable to make the best use of the local generator.

Arrangements for controlling the use of local generators are known.

PCT Published Application WO00/79669 (Gen Tran) discloses a system for bringing into use a local generator in the event of the failure of a mains supply. When the generator is in use, the system has the capability of adding or subtracting loads on the generator in a prescribed order of priority, depending on the demands of the household. As far as the power supply is concerned, it is very clear that connection to the mains supply or the generator is an either/or function. Specifically, the system has a break-before-make relay, which precludes the connection of both at the same time. There is no provision for the feedback of power from the generator to the mains supply.

US Published Specification 2004/0254654 (Donnelly et al) discloses a system for balancing electrical loads between different household appliances, (or between different functions within a single appliance) from a single source of electrical power. The total amount of electrical power applied to the system and the distribution of electrical power within the system can be controlled. However, there is no local generator, nor indeed any provision to feed power back from the, appliances to the external generator or generators.

European Published Application EP 1 626 322 (Robert Bosch GmbH) deals with the distribution of power in a vehicle having a generator and a battery. Power requirements within the vehicle are prioritized so that high priority functions (e.g. lighting) will receive power in preference to low priority functions such as rear window heating and air conditioning. The disclosure deals with battery conditions such as amount of charge retained, age and temperature. While the generator can - at times of low energy demand - supply current to recharge the battery, there is clearly no provision for the battery to supply the generator. In the isolated electrical system of a vehicle, feed back of locally generated power to an external source of power is not possible.

Disclosure of the Invention

The invention provides an arrangement for use in an electrical power consumption system associated with a local electrical generator and an external electrical supply, the arrangement including electrical connections for at least two electrical appliances and a control unit comprising a comparison device to compare the amounts of electrical consumption required by different electrical appliances within the system and a power allocation device to allocate power from the local electrical generator or the external electrical supply to the electrical appliances according to specified priorities, and a user preference interface to facilitate the input of user defined data into the power allocation device, whereby the control unit can optimize usage of the power available from the local electrical generator , and when possible return power from the local electrical generator to the external electrical supply.

In many preferred forms, the power consumption system is associated with a mains electrical supply.

In one preferred form, communication between the control unit and the different electrical appliances is by wireless technology. Alternatively, communication between the control unit and the different electrical appliances is hard wired. The local electricity generator is a micro power generation unit specifically arranged to supply the power consumption system. The micro power generation unit may be part of a micro Combined Heat and Power unit generating electricity or a wind turbine generating electricity, or at least one solar panel generating electricity. In one preferred form the arrangement can operate with electrical appliances configured to resume their predetermined cycle following the cut off and resumption of electrical power supply, and in this preferred form each electrical appliance may have an associated adaptor capable of sending and receiving signals from the control unit. Alternatively or additionally the arrangement can operate with at least one electrical appliance having programmable features.

Programmable features in the control unit may ^nc|ud_,8 ^pe and/or tirηp Interval parameters. In another preferred form at least one of the appliances has provision to feedback its maximum electrical consumption characteristics to the control unit, and the control unit has provision to set these characteristics as a default setting for that appliance. In this last mentioned form it is preferred that all the appliances have provision to feedback maximum electrical consumption characteristics to the control unit. It is further preferred that before incorporation into the system, an appliance has imprinted characteristics, and the control unit has the capability of reading these characteristics when the appliance is incorporated into the system. Preferably user defined data includes user priority preferences.

The arrangement may be programmed at user's discretion to give priority to one appliance over another appliance to maximize use of electricity from the local electrical generator. The arrangement may be programmed to run the appliances in a predetermined order. There may be more than one local electrical generator, and in this case the control unit can be set to distribute electrical energy from other local electrical generators in a specified user defined order of priorities.

In one preferred form, the control unit is supplied with a pre-defined set up programme appropriate for the category of expected usage, which can be personalized by the user preference interface.

In another preferred form the user interface controls all appliances within the system .

In circumstances when the arrangement depends upon mains electrical supply, the comparison device has the ability to recognize different pricing regimes for mains electrical supply, and to determine whether or not to return power to the external electrical supply.

There may be means to isolate the local electrical generator, so that the arrangement is capable of optimizing use of the mains supply.

Brief Description of the Drawings

Figure l is a schematic diagram illustrating an arrangement according to the invention as applied to a household with modern household appliances having integrated controls;

Figure 2 is a similar diagram illustrating an arrangement for a household having household appliances without integrated controls; and

Figure 3 is a representation of an adaptor for use in the arrangement of Figure 2. Description of Specific Embodiments of the Invention

Figure 1 illustrates a household having a local electricity generator 10 such as a micro Combined Heat and Power (mCHP) unit, a wind turbine, or an array of PV solar panels. The exact nature of the local electricity generator is not important, but it will have the capability of feeding alternating current back to an external (mains) electricity supply 11.

The household has numerous appliances such as a dishwasher 12a with integrated controls for washing cycles, a washing machine 12b and a tumble dryer 12c. Other functions within the household draw electricity from the same sources of supply. (Examples are lighting, central heating, TV, computer and computer accessories, music systems and cooking. Some of these functions may not have integrated controls, but all will run off the same power supply.)

Following the invention, there is a control unit 14 comprising a comparison device 14a and a power allocation device 14b. These are shown adjacent to the local electricity generator 10, but need not necessarily be so located. The control unit 14 has the capability of using Bluetooth wireless technology to derive consumption levels from all the appliances. In new housing, a hard wired connection network could be inserted in the building during construction.

The comparison device 14a can assess the current usage in the household and the power available from the local electricity generator 10. The power allocation device 14b can switch appliances 12a etc on and off in accordance with the householder's preferences. The householder's preferences can be set using a user preference interface 15. This may be on the control unit, or, as illustrated, may be remote from the system in the form of a mobile 'phone, PC or other dedicated user interface using Bluetooth or other wireless technology.

Figure 2 illustrates a household having older appliances, none of which have integrated controls. The arrangement is basically the same, with a local electricity generator 110, external supply 111, appliances 112a etc, and a control unit 114. In this case each appliance to which control is to be is applied has an adaptor 117a etc. The configuration of the adaptor is shown in Figure 3. The supply 109 feeds a fixed plug socket 116, and then, through the adaptor 117, the appliance 112. In this way a house with old appliances can be set up to take advantage of the arrangement according to the invention.

In the specific embodiments described above a load balancing arrangement is used in a property where power is delivered directly from the grid (mains) and supplemented by local generation, with at least two appliances connected to this system.

Local generation presents two main ways for consumer to make savings. Firstly, power generated within the property by a local electricity generator will generate less carbon emissions than the equivalent amount generated at a coal, oil, or gas fired power plant and delivered to the consumer. Secondly, power generated locally within the property will typically cost significantly less when used within the property compared to the same amount of power when delivered via the mains.

When local generation supplements the mains supply of electricity, one of two things can happen to the power it generates. What happens depends on the base load of the property at that instant. Any power generated by local generation will be used to cover the base load of the property; if any is generated in excess of the base load it may be exported back to the grid. For example, assume the local generator is a mCHP unit that produces 3kW of electrical power. If the base load of a property at a moment is 2kW, then of the 3kW locally generated power available, 2kW will be used to drive the base load and the remaining IkW will be exported back to the grid. However, if for example the base load on the property is 5kW, all 3kW that is been locally generated will be used to drive the base load, plus a further 2kW will be imported from the grid to cover it.

As previously mentioned it is much cheaper for the consumer to use electricity that has come from local generation, than that supplied by the mains. If electricity is exported, then a fee is paid back to the consumer. However, this is still less than what they would get if they had bought the electricity. Therefore it can be seen that the ideal scenario in terms of carbon savings and cost savings, is that when the local generator is producing electricity, ideally all that electricity should be used within the property, with little or none being exported and as little as practical should be imported from the mains. It is the role of the load balancing arrangement to achieve this optimisation.

It should also be noted that for some consumers, mains electricity is cheaper at different times of the day. Therefore the load balancing arrangement may also be configured to make best use of these rates if there is no locally generated electricity available.

In operation, the load balancing arrangement will work differently depending on whether it is connected to older style appliances (rocker switch operation, hard on-off, no time delay function etc) rather than to new appliances that can communicate directly with the control unit 14/114. In the context of this description, an appliance is defined as any electrical equipment that is likely to be near permanently connected to the grid within the property. The appliances are likely to be able to operate automatically. Types of appliances 12/112 include but are not limited to cookers, washing machines, tumble dryers, slow cookers, point of use heaters, dishwashers, dehumidifiers etc.

With some newer appliances, it is anticipated that the power they require for each of their different operating modes is permanently stored in memory inside the appliance. This memory should be capable of been read over a communication link with the control unit 14/114. The communication link between appliances and the control unit may be a physical wired link, or it may use a wireless technology such as Bluetooth. By knowing which appliances the user has requested to run, how much power each one uses and for how long, and by knowing how much power is been generated locally, how long this power is likely to be generated for, and any time or priority constraints placed by the user, the power allocation device 14b/l 14b can calculate how to make best use of the local power to achieve maximum savings. It will do this by giving different appliances priority and running them at different time as a result, all dependant on the quantity of locally generated power available.

The specific examples illustrate arrangements which are not trying to regulate the amount of energy that each appliance uses for its operation, as this can lead to sub optimal performance from the appliance. The control unit 14/114 can turn appliances on and off, and run them at different times to regulate the load within the property, relative to the amount of locally generated or cheap mains energy available.

Which appliances to run, the priority each appliance has, and any time constrains or over-rides are all communicated to the control unit 14/114 via a user interface module 15/115. For example, this is a separate, hand held man-machine interface that communicates with the control unit 14/114 using the same wireless protocols previously mentioned. It may also be used for other settings, such as setting the clock, adding and removing appliances, inputting energy costs etc.

EXAMPLE 1

For example, assume that a consumer in the morning loads the washing machine, tumble dryer and dishwasher and then leaves for work. The property has a mCHP fitted and this is programmed to come on at 2pm for afternoon and evening heating if required, and hence at this time onwards will be generating electricity. On the user interface 15/115 the consumer has given priority to the washing machine 12b/l 12b as this is the most important job to be completed. When 2pm is reached, the heating comes on, and hence the mCHP starts generating electricity, 3kW in this case. Priority has been given to the washing machine, so the control unit 14/114 sends a signal to the washing machine to determine what setting it is on, in this case it is a heavy wash that will use 2kW for 2 hours. The control unit then checks the recent average base load of the house, which is 0.7kW. Knowing that it has 3 - 0.7 = 2.3kW of locally generated power available it sends a signal for the washing machine to run its cycle. The next appliance is the tumble dryer 12c/l 12c, and this has communicated that it needs 1.5kW for lhour. Knowing that it presently only has 0.3kW of locally generated energy available, the power allocation device 14b/l 14b would wait until more was available before starting the tumble dryer. If it didn't wait, it would need to import energy from the grid 11/111, thus costing money. More energy becomes available when either the washing machine finishes or the average base load drops.

EXAMPLE 2

For a second example, using the same assumptions as above, the washing machine 12b/l 12b is put on a light wash which this time needs IkW for 2 hours. There is still the same 3.0-0.7kW of locally generated energy available so the control unit 14/114 sends the signal for the washer to do its cycle. The tumble dryer 12c/l 12c then communicates that it again requires 1.5kW for 1 hour. This time there is 1.3kW of locally generated energy available, so this time the tumble dryer could be run. However it would also get the requirement from the dishwasher, which is IkW for one hour. Therefore running the dishwasher leaves a little energy spare for export while running the tumble dryer leaves a little energy to import. Knowing the relative costs of these energies, the control unit will determine which one is the more cost effective to run.

OTHER EXAMPLES

The control unit 14/114 will be able to perform other functions too, such as applying time constraints. For example, a program may be run similar to those in the specific examples above, but it may be at a warmer time of year, so there could be no guarantee that the heating switches on, and hence that local energy is generated by the mCHP. Therefore a time constraint could be applied to the washing machine 12b/l 12b that requires that it must be finished before 5pm. So if, like in the above example, the heating comes on at 2pm and electricity is generated, the washing machine would run then. However, if it had got to 3pm and the heating had not yet switched on so there was no local generation, knowing that the washing machine is set for a 2 hour cycle, the control unit 14/114 would start the washing machine anyway so that the cycle is finished for the user selected time of 5pm. Another useful function is an over-ride function. If circumstances should change once appliances, priorities and time constraints have been set, the user is able to over-ride these. For example, if in one of the above examples the person comes home early and needs the items in the dishwasher 12a/ 112a to make dinner, it may not be possible as the dishwasher may not have started its cycle yet due to the load balancing and available locally generated power. Therefore a function could be included that starts any of the scheduled appliances on their cycle immediately, hence over-riding the power allocation device 14b/114b.

The above applies to appliances with the memory and communications functions built into them, as indicated with reference to Figure 1. With older appliances as in Figure 2, this would not be the case as they do not have anything like that built in. Therefore an adapter 117 would be fitted in between the appliance and its connection to the electrical socket 116 on the wall. The adapter is there to switch the appliance 112 on and off, measure its power consumption when running, and to communicate with the control unit 114, by either wired or wireless methods mentioned above.

The user would 'add' any new appliance to the load balancing arrangement via the user interface 115 so that the control unit 114 was aware of the new appliance. A basic power profile for that appliance would then be inserted into the comparison device 114a, since its actual power profile is not yet known. (Power profile meaning it requires 2kW for 3 hours for example.) When the new appliance is first run, the adapter 117 measures the amount of power the appliance uses over its cycle. The power profile for that appliance is then adjusted to these more accurate values from the basic ones now that the accurate values are known. With this information, the comparison device can now behave in the same way as described above for the new appliance.

It may be possible for manufacturers of load balancing arrangements to pre programme units specifically for general classes of use, e.g. for two bedroom flats or four bedroom houses. It may also be possible for appliance manufacturers to preprogram appliances to be added to existing arrangements on a 'plug and play' basis, so that the new appliance identifies its power requirements to the comparison device. For example, a washing machine could be programmed to identify with a light or a heavy wash cycle. Advantages of the Invention

The load balancing arrangement is capable of balancing modes of economical operation both up and down stream of the comparison/allocation device.

Both mains and local electrical supplies are used to their best advantage either jointly or severally. When used jointly, electricity can be exported back to the mains supply.

The arrangement does not limit the performance of the appliances (i.e. by resulting in sub-optimal performance), but runs the appliances with no limitations when energy is available.

Users have the assurance that there is the possibility of more than one local micro generation source as well as mains supply.

The arrangement enables manufacturers to load energy requirement specifications into new appliances, so making them 'plug and play' directly into household systems.

Claims

1/ An arrangement for use in an electrical power consumption system associated with a local electrical generator (10) and an external electrical supply (11), the arrangement including electrical connections for at least two electrical appliances (12a, 12b) and a control unit (14) comprising a comparison device (14a) to compare the amounts of electrical consumption required by different electrical appliances within the system and a power allocation device (14b) to allocate power from the local electrical generator (10) or the external electrical supply (11) to the electrical appliances according to specified priorities, and a user preference interface (15) to facilitate the input of user defined data into the power allocation device, whereby the control unit (14) can optimize usage of the power available from the local electrical generator (10), and when possible return power from the local electrical generator to the external electrical supply (11).

2/ An arrangement as claimed in claim 1, in which the power consumption system is associated with a mains electrical supply.

3/ An arrangement as claimed in claim 1 or claim 2, in which communication between the control unit and the different electrical appliances is by wireless technology.

4/ An arrangement as claimed in claim 1 or claim 2 in which communication between the control unit and the different electrical appliances is hard wired.

5/ An arrangement as claimed in any one of the preceding claims, in which the local electricity generator is a micro power generation unit specifically arranged to supply the power consumption system.

6/ An arrangement as claimed in claim 5, in which the micro power generation unit is part of a micro Combined Heat and Power unit generating electricity.

11 An arrangement as claimed in claim 5, in which the micro power generation unit is a wind turbine generating electricity.

8/ An arrangement as claimed in claim 5, in which the micro power generation unit is at least one solar panel generating electricity. 9/ An arrangement as claimed in any one of claims 1 to 8, and arranged to operate with electrical appliances configured to resume their predetermined cycle following the cut off and resumption of electrical power supply.

10/ An arrangement as claimed in claim 9, in which each electrical appliance has an associated adaptor capable of sending and receiving signals from the control unit. 11/ An arrangement as claimed in any one of claims 1 to 8, and arranged to operate with at least one electrical appliance having programmable features.

12/ An arrangement as claimed in any one of the preceding claims, in which programmable features in the control unit include time and/or time interval parameters.

13/ An arrangement as claimed in any one of the preceding claims, in which at least one of the appliances has provision to feedback its maximum electrical consumption characteristics to the control unit, and the control unit has provision to set these characteristics as a default setting for that appliance. 14/ An arrangement as claimed in claim 13, in which all the appliances have provision to feedback maximum electrical consumption characteristics to the control unit

15/ An arrangement as claimed in claim 13 or claim 14, in which before incorporation into the system, an appliance has imprinted characteristics, and the control unit has the capability of reading these characteristics when the appliance is incorporated into the system.

16/ An arrangement as claimed in any one of the preceding claims, in which the user defined data includes user priority preferences.

17/ An arrangement as claimed in any one of the preceding claims in which the control unit can be programmed at users' discretion to give priority to one appliance over another appliance to maximize use of electricity from the local electrical generator.

18/ An arrangement as claimed in any one of the preceding claims 1 to 17, in which the control unit can be programmed to run the appliances in a predetermined order. 19/ An arrangement as claimed in any one of the preceding claims in which there is more than one local electrical generator, and the control unit can be set to distribute electrical energy from other local electrical generators in a specified user defined order of priorities.

20/ An arrangement as claimed in any one of the preceding claims, in which the control unit is supplied with a pre-defined set up programme appropriate for the category of expected usage, which can be personalized by the user preference interface.

21/ An arrangement as claimed in any one of the preceding claims, in which the user interface controls all appliances within the system. 22/ An arrangement as claimed in claim 2 and any one of the preceding claims depending on claim 2, in which the comparison device has the ability to recognize different pricing regimes for mains electrical supply, and to determine whether or not to return power to the external electrical supply accordingly.

23/ An arrangement as claimed in claim 2 and any one of claims 3 to 22 as dependent on claim 2, in which there is means to isolate the local electrical generator, so that the arrangement is capable of optimizing use of the mains supply.