ELECTRICAL ENERGY STORAGE DEVICE AND SYSTEM

• US 20160049790A1
• Filed: 03/21/2014
• Published: 02/18/2016
• Est. Priority Date: 03/21/2013
• Status: Active Grant

• Current Assignee: Powervault Limited
• Original Assignee: Powervault Limited
• Inventors: Wordsworth, Andrew, Duffin, Anthony, Duffin, Thomas
• Granted Patent: US 10,630,076 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 25/00 Arrangements for measuring phase angle between a voltage and a current or between voltages or currents
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: H02J 13/00001 characterised by the display of information or by user interaction, e.g. supervisory control and data acquisition systems [SCADA] or graphical user interfaces [GUI]
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 40/70 Smart grids as climate change mitigation technology in the energy generation sector
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin
• CPC Class Codes: Y04S 10/123 the energy generation units being or involving renewable energy sources
• CPC Class Codes: Y04S 10/14 Energy storage units
• CPC Class Codes: Y04S 10/40 Display of information, e.g. of data or controls
• CPC Class Codes: Y04S 10/50 Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
• CPC Class Codes: Y04S 20/12 Energy storage units, uninterruptible power supply [UPS] systems or standby or emergency generators, e.g. in the last power distribution stages

Abstract

An electrical energy storage device comprises an electrical connection arranged to detachably connect to a power distribution system on a site; an energy store having an input arranged selectively to charge the energy store from the distribution system, and an output arranged selectively to discharge the energy store to the distribution system; a processor arranged to monitor at least one condition relating to the site, and to monitor at least one condition relating to the energy store, and to control the energy store to charge or to discharge dependent upon the monitored conditions; and preferably a communication interface for the processor. Such a device could be provided in a domestic site, in particular a site having a generation capacity such as PV panels, in order for the energy consumer at the site to obtain an electrical energy supply more efficiently or more cheaply, and in order to smooth out fluctuations in energy supply and/or demand from the site.

Claims

1-24. -24. (canceled)

25. An electrical energy storage device for a site comprising:

an electrical connection arranged to detachably connect to an electrical power system on the site;

an energy store having an input arranged selectively to charge the energy store from the electrical power system, and an output arranged selectively to discharge the energy store to the electrical power system; and

a processor arranged to monitor at least one condition relating to the site, and to monitor at least one condition relating to the energy store, and to control the energy store to charge or to discharge dependent upon the monitored conditions.

26. The electrical energy storage device as claimed in claim 25, comprising a communication interface for the processor.

27. The electrical energy storage device as claimed in claim 25, in which the condition relating to the site includes one or more of the level of power generated at the site, the level of power demand at the site, the time and/or date, the tariff for purchasing power from the system, and the weather conditions at the site.

28. The electrical energy storage device as claimed in claim 25, in which the condition relating to the energy store includes at least one of the energy store level, the voltage or temperature of the energy store, or the input or output current of the energy store.

29. The electrical energy storage device as claimed in claim 25, in which the processor is arranged to control the energy store in dependence upon one or more of a past value, a current value and a future value of the monitored conditions.

30. The electrical energy storage device as claimed in claim 25, in which the conditions are monitored either continuously or periodically.

31. The electrical energy storage device as claimed in claim 25, in which the processor is arranged to control the energy store to charge or discharge when both the condition(s) relating to the site and the condition(s) relating to the energy store meet predetermined criteria.

32. The electrical energy storage device as claimed in claim 25, in which the processor is arranged to operate the energy store input to charge the energy store when power generated at the site exceeds power demand at the site, if the energy store is below a predetermined level of charge.

33. The electrical energy storage device as claimed in claim 25, in which the processor is arranged to operate the output of the energy store to discharge when power demand on the site exceeds power generated on the site, if the energy store is above a predetermined level of charge.

34. The electrical energy storage device as claimed in claim 25, in which the processor is arranged to control the energy store input to charge at a time when the purchase price of power from the supply system is below a predetermined level, if the energy store is below a predetermined level of charge;

and/or, in which the processor is arranged to control the energy store input to discharge at a time when the purchase price of power from the supply system is above a predetermined level, if the energy store is above a predetermined level of charge.

35. The electrical energy storage device as claimed in claim 25, in which the processor is arranged to receive instructions via the communications interface, and preferably in which the processor comprises a memory for storage of instructions.

36. The electrical energy storage device as claimed in claim 35, in which the interface is arranged to be programmable by the user to provide or modify the instructions.

37. The electrical energy storage device as claimed in claim 25, in which the processor is arranged to determine the charging rate in dependence upon the monitored conditions, preferably including at least one of the charge level, the time available to charge, the power at which it is required to charge, or the amount of energy required to be stored in a given time.

38. The electrical energy storage device as claimed in claim 25, in which the energy store comprises a battery, and the device preferably includes an inverter for converting direct current from the energy store to alternating current for supply to the distribution system.

39. The electrical energy storage device as claimed in claim 25, in which the connection comprises a mains power connection connected to a distribution system such as the national grid, and in which the invertor preferably comprises a mains tied invertor.

40. The electrical energy storage device as claimed in claim 25, in which the device is arranged to be accommodated in a domestic setting, and in which the battery preferably has a usable capacity of more than about 2 kWh and/or less than about 4 kWh.

41. The electrical energy storage device as claimed in claim 25, in which the processor is arranged to receive instructions from the power distribution system, and to control the energy store dependent upon such instructions.

42. An energy management system comprising a plurality of devices as claimed in claim 25, and a controller for providing instructions to the devices.

43. A method of energy management in a system, in which a plurality of devices according to claim 25 are connected to the system, comprising:

monitoring power demand in the system, communicating an instruction to charge the energy store of at least one device connected to the system in the event that demand falls below a predetermined level, and communicating an instruction to discharge the energy store of at least one device in the event that demand exceeds a predetermined level.

48. The electrical energy storage device as claimed in of claim 25, comprising apparatus as claimed in claim 47, the processor being arranged to determine the direction of power flow into or out of the electrical power system on the site.

44. A method of determining a phase difference between the current and voltage waveforms of a power flow at a first location in an electrical power system, comprising:

determining the current waveform at the first location at a first time point;

determining the voltage waveform at a second remote location at a second time point;

determining the time delay between the first time point and the second time point; and

synchronizing the waveforms using the time delay so as to determine a phase difference between the waveforms.

45. The method as claimed in claim 44, comprising using the phase difference between the current and voltage waveforms to calculate at least one of the direction of power flow, the real power, the active power, the reactive power, the harmonics, power factor or an electrical characteristic of the power flow.

46. The method as claimed in claim 44, comprising determining the time delay by sending a first timestamp signal from the first location to the second location, and sending a second timestamp signal from the second location to the first location indicating the time when the first signal was received at the second location.

47. Apparatus for determining the phase difference between the current and voltage waveforms of a power flow at a first location in an electrical power system, comprising:

a current measuring device at the first location arranged to provide a current waveform signal;

a voltage measuring device at a second location arranged to provide a voltage waveform signal; and

a processor,

wherein at least one of the devices is remote from the processor, the processor being arranged to send a first time stamp signal to the remote device(s), and to receive a second time stamp signal from the remote device(s) indicating the time at which the first time stamp signal was received by the device, to determine the time delay between the current waveform signal and the voltage waveform signal, to synchronise the current waveform signal and the voltage waveform signal, and to determine the phase difference between the synchronized signals.