POWER CONTROL SYSTEM

• US 20100282910A1
• Filed: 05/28/2008
• Published: 11/11/2010
• Est. Priority Date: 05/29/2007
• Status: Active Grant

• Current Assignee: Ultra PCS Limited
• Original Assignee: Ultra Electronics Limited (Ultra Electronics Holdings PLC)
• Inventors: Stothers, Ian M., Schneider, Daniel Z.
• Granted Patent: US 8,788,106 B2
• Time in Patent Office: Days
• US Class Current: 244/134D
• CPC Class Codes: B64D 15/14 controlled cyclically along length of surface
• CPC Class Codes: B64D 15/22 Automatic initiation by icing detector
• CPC Class Codes: H02J 2310/44 for aircrafts
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading

Abstract

A method is disclosed for controlling the distribution of power to a plurality of devices, the method being carried out during a plurality of time periods, and the method during each time period after the first comprising: determining (S700) an energy or power deficit for each device based on the difference between a target amount of energy or power and a measured amount of energy or power supplied to the device prior to the current time period; selecting (S702) at least one device in decreasing order of energy or power deficit, whereby priority is given to devices having the largest energy or power deficit or the smallest energy or power surplus, until the selection of any further devices will cause a total estimated power consumption of the selected devices during the time period to exceed a predetermined maximum power consumption; and supplying (S704) power to the or each selected device during the time period.

Claims

1. A method of controlling the distribution of power to a plurality of devices, the method being carried out during a plurality of time periods, and the method during each time period after the first comprising:

determining an energy or power deficit for each device based on the difference between a target amount of energy or power and a measured amount of energy or power supplied to the device prior to the current time period;

selecting at least one device in decreasing order of energy or power deficit, whereby priority is given to devices having the largest energy or power deficit or the smallest energy or power surplus, until the selection of any further devices will cause a total estimated power consumption of the selected devices during the time period to exceed a predetermined maximum power consumption; and

supplying power to the or each selected device during the time period.

2. A method according to claim 1, wherein power is not supplied to unselected devices.

3. A method according to claim 1, wherein, for time periods other than the first, the determination of an energy or power deficit for each device comprises subtracting (a) a target amount of energy or power desired to be supplied to the device during the preceding time period from the sum of:

(b) a measurement of the actual amount of energy or power supplied to the device during the preceding time period, and (c) the determined energy or power deficit of the preceding time period.

4. A method according to claim 3, wherein, for the first time period, the method comprises setting the energy or power deficit to an initialisation value.

5. A method according to claim 1, wherein the selection of at least one device comprises:

arranging device data associated with respective devices into a list sorted by decreasing size of energy or power deficit of each respective device;

selecting device data from the top of the list;

calculating the total estimated power consumption of the devices associated with the selected device data; and

continuing the selection of device data until the selection of any further device data would cause the total estimated power consumption to exceed the predetermined maximum power consumption.

6. A method according to claim 1, wherein supplying power to the or each selected device comprises switching on the or each selected device and switching off unselected devices.

7. A method according to claim 6 for use with an alternating current power supply, wherein the method further comprises switching the or each device at zero-crossing points of the current or voltage of the power supply.

8. A method according to claim 1 for use with a multiple phase power supply, wherein the method is carried out in respect of each phase of the multiple phase power supply.

9. A method according to claim 8, further comprising processing a signal representative of an imbalance in the current or voltage of the multiple phases, and adjusting the maximum power consumption in order to reduce the imbalance.

10. A method according to claim 8 for use with a power supply including a neutral path, wherein the method further comprises supplying power during at least one time period through only a selected one of the phases, processing a signal representative of a measurement of the current flowing through the neutral path, and determining an electrical property of at least one of the devices connected to said selected one of the phases in dependence on the current measurement.

11. A method according to claim 10, further comprising calibrating an electrical sensor connected to said selected one of the phases in dependence on the determined electrical property.

12. A method according to claim 1, wherein the plurality of devices comprises a plurality of heater elements, and the time period is less than the thermal time constant of at least one of the heater elements.

13. A method according to claim 1, further comprising substantially normalising the energy or power deficit with respect to the target amount of energy or power respectively.

27. A vehicle comprising:

a power supply;

a plurality of devices; and

apparatus as claimed in claim 10, for supplying power from the power supply to the plurality of devices.

44. A carrier medium carrying computer readable code for controlling a computer to carry out the method of claim 1.

14. Apparatus for controlling the distribution of power to a plurality of devices during a plurality of time periods, the apparatus comprising:

means for determining an energy or power deficit for each device during each time period, the determination being based on the difference between a target amount of energy or power and a measured amount of energy or power supplied to the device prior to the time period;

means for selecting at least one device during each time period in decreasing order of energy or power deficit, whereby priority is given to devices having the largest energy or power deficit or the smallest energy or power surplus, until the selection of any further devices will cause a total estimated power consumption of the selected devices during the time period to exceed a predetermined maximum power consumption; and

means for supplying power to the or each selected device during each time period.

15. Apparatus according to claim 14, wherein the means for supplying power is operable to not supply power to unselected devices.

16. Apparatus according to claim 14, wherein the means for determining an energy or power deficit is operable, in respect of time periods other than the first, to determine the energy or power deficit for each device by subtracting (a) a target amount of energy or power desired to be supplied to the device during the preceding time period from the sum of:

(b) a measurement of the actual amount of energy or power supplied to the device during the preceding time period, and (c) the determined energy or power deficit of the preceding time period.

17. Apparatus according to claim 16, wherein the means for determining an energy or power deficit is operable, in respect of the first time period, to set the energy or power deficit to an initialisation value.

18. Apparatus according to claim 14, wherein the means for selecting at least one device is operable to:

arrange device data associated with respective devices into a list sorted by decreasing size of energy or power deficit of each respective device;

select device data from the top of the list;

calculate the total estimated power consumption of the devices associated with the selected device data; and

continue the selection of device data until the selection of any further device data would cause the total estimated power consumption to exceed the predetermined maximum power consumption.

19. Apparatus according to claim 14, wherein the means for supplying power to the or each selected device is operable to switch on the or each selected device and to switch off unselected devices.

20. Apparatus according to claim 19, operable with an alternating current power supply, and wherein the means for supplying power is operable to switch the or each device at zero-crossing points of the current or voltage of the power supply.

21. Apparatus according to claim 14, operable to supply power from a plurality of phases of a multiple phase power supply.

22. Apparatus according to claim 21, further comprising means for processing a signal representative of an imbalance in the current or voltage of the multiple phases, and means for adjusting the maximum power consumption in order to reduce the imbalance.

23. Apparatus according to claim 21, operable with a power supply including a neutral path, wherein the apparatus is operable to supply power during at least one time period through only a selected one of the phases, to process a signal representative of a measurement of the current flowing through the neutral path, and to determine an electrical property of at least one of the devices connected to said selected one of the phases in dependence on the current measurement.

24. A method according to claim 23, further comprising means for calibrating an electrical sensor connected to said selected one of the phases in dependence on the determined electrical property.

25. Apparatus according to claim 14, wherein the plurality of devices comprises a plurality of heater elements, and the time period is less than the thermal time constant of at least one of the heater elements.

26. Apparatus according to claim 14, wherein the apparatus is operable substantially to normalise the energy or power deficit with respect to the target amount of energy or power respectively.

28. An ice protection system for an aircraft, including apparatus as claimed in claim 14.

29. A power controller for controlling the distribution of power to a plurality of devices during a plurality of time periods, comprising:

a switching unit for switching power to said plurality of devices;

an instruction memory storing processor implementable instructions; and

a processor operable to process data in accordance with instructions stored in the instruction memory;

wherein the instructions stored in the instruction memory comprise instructions for controlling the processor to perform a method comprising;

determining an energy or power deficit during each time period for each device based on the difference between a target amount of energy or power and a measured amount of energy or power supplied to the device prior to the time period;

selecting at least one device during each time period in decreasing order of energy or power deficit, whereby priority is given to devices having the largest energy or power deficit or the smallest energy or power surplus, until the selection of any further devices will cause a total estimated power consumption of the selected devices during the time period to exceed a predetermined maximum power consumption; and

supplying power to the or each selected device during the time period.

30. A power controller according to claim 29, wherein the instructions when executed by the processor cause the power controller not to supply power to unselected devices.

31. A power controller according to claim 29, wherein the instructions when executed by the processor cause the power controller, in respect of time periods other than the first, to determine of an energy or power deficit for each device by subtracting (a) a target amount of energy or power desired to be supplied to the device during the preceding time period from the sum of:

(b) a measurement of the actual amount of energy or power supplied to the device during the preceding time period, and (c) the determined energy or power deficit of the preceding time period.

32. A power controller according to claim 31, wherein the instructions when executed by the processor cause the power controller, in respect of the first time period, to set the energy or power deficit to an initialisation value.

33. A power controller according to claim 29, wherein the instructions when executed by the processor cause the power controller to select at least one device by:

arranging device data associated with respective devices into a list sorted by decreasing size of energy or power deficit of each respective device;

selecting device data from the top of the list;

calculating the total estimated power consumption of the devices associated with the selected device data; and

continuing the selection of device data until the selection of any further device data would cause the total estimated power consumption to exceed the predetermined maximum power consumption.

34. A power controller according to claim 29, wherein the instructions when executed by the processor cause the power controller to supply power to the or each selected device by switching on the or each selected device and switching off unselected devices.

35. A power controller according to claim 34, wherein the power controller is operable to supply power from an alternating current power supply, and the instructions when executed by the processor cause the power controller to switch the or each device at zero-crossing points of the current or voltage of the power supply.

36. A power controller according to claim 29, wherein the power controller is operable to supply power from a plurality of phases of a multiple phase power supply.

37. A power controller according to claim 36, wherein the power controller is operable to process a signal representative of an imbalance in the current or voltage of the multiple phases, and to adjust the maximum power consumption in order to reduce the imbalance.

38. A power controller according to claim 36 for use with a power supply including a neutral path, wherein the power controller is operable to supply power during at least one time period through only a selected one of the phases, to process a signal representative of a measurement of the current flowing through the neutral path, and to determine an electrical property of at least one of the devices connected to said selected one of the phases in dependence on the current measurement.

39. A power controller according to claim 38, operable to calibrate an electrical sensor connected to said selected one of the phases in dependence on the determined electrical property.

40. A power controller according to claim 29, wherein the plurality of devices comprises a plurality of heater elements, and the time period is less than the thermal time constant of at least one of the heater elements.

41. A power controller according to claim 29, operable substantially to normalise the energy or power deficit with respect to the target amount of energy or power respectively.

42. A method of controlling the distribution of power to a plurality of devices, the method being carried out during a plurality of time periods, and the method during each time period comprising:

determining an energy or power deficit for each device;

selecting at least one device, giving priority to devices having the largest energy or power deficit, such that as many devices as possible are selected without causing a total estimated power consumption of the selected devices during the time period to exceed a predetermined maximum power consumption; and

supplying power to the or each selected device during the time period.

47. A carrier medium carrying computer readable code for controlling a computer to carry out the method of claim 42.

43. Apparatus for controlling the distribution of power to a plurality of devices during a plurality of time periods, the apparatus comprising:

means for determining an energy or power deficit for each device during each time period;

means for selecting at least one device during each time period, giving priority to devices having the largest energy or power deficit, such that as many devices as possible are selected without causing a total estimated power consumption of the selected devices during the time period to exceed a predetermined maximum power consumption; and

means for controlling the distribution of the power such that power is supplied to the or each selected device during the time period.

45-46. -46. (canceled)