Energy allocation system for balancing energy consumption

• US 9,946,285 B2
• Filed: 12/19/2012
• Issued: 04/17/2018
• Est. Priority Date: 12/23/2011
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Binding, Carl, Sundstroem, Olle L.
• Primary Examiner(s): Rashid, Wissam
• Application Number:
  US14/366,530
• Publication Number:
  US 20150127179A1
• Time in Patent Office: 1,945 Days
• Field of Search: None
• CPC Class Codes: G05B 13/026 using a predictor
• CPC Class Codes: G05F 1/66 Regulating electric power
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: H02J 3/003 Load forecast, e.g. methods or systems for forecasting future load demand
• CPC Class Codes: H02J 3/28 Arrangements for balancing of the load in a network by storage of energy
• 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: 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 40/20 Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

The present invention relates to an energy allocation system for operating at least an energy storage device to substantially balance the energy consumed by the energy storage device with the energy supplied thereto, comprising the steps of: determining a power flexibility of the energy storage device by generating an upper time-varying power function; predicting energy consumption data per discrete time-slots over a given time-window for the device; predicting a demand for energy by the device in a given planning time-period; generating a time-varying upper energy function for the demand prediction that defines an uppermost limit for the supply of energy to the device; generating a time-varying lower energy function for the demand prediction that defines a lowermost limit for the supply of energy to the device, and supplying energy to the device in a range defined by the limits specified by the upper energy function and the lower energy function.

Claims

1. A method for operating at least an energy storage device to substantially balance the energy consumed by the energy storage device with the energy supplied thereto, comprising:

determining a power flexibility of the energy storage device by generating an upper time-varying power function and a lower time-varying power function that respectively represent the maximum power and the minimum power that can be supplied to the device at any given point in time when the energy storage device is in use;

predicting energy consumption data per discrete time-slots over a given time-window for the device;

predicting a demand for energy by the device in a given planning time-period by consecutively accumulating the predicted energy consumption data per discrete time-slots in the planning time-period that correspond with the discrete time-slots in the time-window over which the energy consumption data is predicted;

generating a time-varying upper energy function for the demand prediction that defines an uppermost limit for the supply of energy to the device;

generating a time-varying lower energy function for the demand prediction that defines a lowermost limit for the supply of energy to the device, and

supplying energy to the device in a range defined by and between the limits specified by the upper energy function and the lower energy function,

wherein, in the generating of the upper energy function, energy is taken to be supplied to the device immediately after the occurrence of an energy consumption event and so as to replenish the device with the energy consumed in the energy consumption event.

2. The method as claimed in claim 1 wherein, in the supplying of energy to the device, the power provided to the device at any given point in time is selected to be within a range defined by, and between, the limits specified by the upper power function and the lower power function.

3. The method as claimed in claim 1 wherein, in the generating of the lower energy function, energy is taken to be supplied to the energy storage device just before the occurrence of an energy consumption event and such that a demand for energy corresponding to that energy consumption event is met.

4. The method as claimed in claim 3 wherein an initial amount of energy e0 in the energy storage device at a given point in time before the occurrence of a given set of energy consumption events, a maximum amount of energy e_max that may be provided to the energy storage device, and a minimum amount of energy e_min to be maintained in the energy storage device are determined.

5. The method as claimed in claim 4 wherein, in the generating of the upper energy function, the energy levels in the energy storage device are taken to be ramped from the initial amount of energy e0 stored in the device to the maximum amount of energy e_max that may be provided to the energy storage device, before the occurrence of any energy consumption events.

6. An energy allocation system for allocating energy to at least a given set of energy storage devices that are arranged in a hierarchical tree of nodes comprising at least a parent node with corresponding children nodes, thereby to substantially balance energy consumption by each of the energy storage devices with the energy supplied thereto, the system comprising:

at least a prediction layer being configurable to predict at least a demand for energy in discrete time-slots in a given planning time-period in the future and to generate power flexibility data for each of the energy storage devices in the given set from information on at least an energy status and event status of each of the devices at a given point in time;

an aggregation layer comprising an aggregation sub-layer that is configurable to hierarchically aggregate the energy demand prediction and power flexibility data for the given set of energy storage devices, and an aggregation top-layer that is configurable to aggregate the results of the aggregation sub-layer, thereby to obtain data on the total energy demand prediction and power flexibility for the given set of energy storage devices;

an allocation layer, which is configurable to generate a reference power supply curve indicating the power available for supply in the discrete time-slots of the planning time-period to the given set of energy storage devices based on the aggregation results received from the aggregation top-layer and a prediction on the energy supply by a given energy resource that has been selected to supply energy to the given set of energy storage devices,

wherein the aggregation layer is configurable to hierarchically disaggregate the reference power supply curve into individual power supply curves for provision to each of the energy storage devices in the given set of energy storage devices, thereby giving each of the energy storage devices a corresponding power schedule to be followed on when to consume energy and how much energy to consume in a given point in time when the energy storage device is in use in the given planning time-period.

7. The energy allocation system as claimed in claim 6 wherein the power flexibility data for a given energy storage device is given by an upper time-varying power function and a lower time-varying power function that respectively represent the maximum power and the minimum power that can be supplied to the given energy storage device at any point in time when it is in use.

8. The energy allocation system as claimed in claim 6 wherein the energy status on any given energy device comprises predicted data on the energy consumption by that device in discrete time-slots in a given time-window that correspond with the discrete time-slots in the planning time-period, with the energy demand prediction being done by consecutively accumulating the predicted energy consumption data per discrete time-slots in the planning time-period.

9. The energy allocation system as claimed in claim 8 wherein the demand for energy by a given energy storage device in the given planning time-period is given by:

an upper energy function, where energy is taken to be supplied to the energy storage device immediately after the occurrence of an energy consumption event and so as to replenish the energy storage device with the energy consumed in that energy consumption event;

a lower energy function, where energy is taken to be supplied to the energy storage device just before the occurrence of an energy consumption event and such that a demand for energy corresponding to that energy consumption event is met, and the initial amount energy e0 in the energy storage device at a given point in time before the occurrence of a given set of energy consumption events.

10. The energy allocation system as claimed in claim 6 wherein hierarchical aggregation at the aggregation layer is done by the addition of the respective power flexibility values and the addition of the respective energy demand predictions for the given set of energy storage devices.

12. The energy allocation system as claimed in claim 6 wherein information on a geographic location of at least a given energy storage device is provided to the prediction layer.

13. The energy allocation system as claimed in claim 6 wherein the prediction layer is configurable to reiterate energy demand prediction and generation of power flexibility data for at least a given parent node in response to a trigger being provided by at least one of its corresponding children nodes.

11. The energy allocation system as claimed in 10 wherein hierarchical disaggregation is performed such that the power to be supplied to the given set of devices in a given time-slot in the planning time-period is a sum of the power to be supplied to each of the storage devices in that time-slot and such that constraints set by the power flexibility and energy demand prediction for each of the energy storage devices are met.

14. A control loop for the allocation of energy to at least an energy storage device thereby to substantially balance energy consumption by the energy storage device with the energy supplied thereto, comprising:

at least an energy consumption monitoring unit for predicting data on the energy consumption by the energy storage device over a given time-window when the energy storage device is in use;

at least a demand prediction unit for;

predicting a demand for energy by the energy storage device in a given planning time-period in the future on the basis of the predicted energy consumption data, generating a time-varying upper energy function for the predicted energy demand that defines an uppermost limit for the supply of energy to the device, and generating a time-varying lower energy function for the predicted energy demand that defines a lowermost limit for the supply of energy to the device;

at least an energy supply prediction unit for predicting energy supply in the given planning time-period by a given energy resource that has been selected to supply energy to the energy storage device; and

at least a schedule provider unit for producing a schedule for the provision of power to the energy storage device in the given planning time-period on the basis of the predicted energy demand of the energy storage device and the predicted energy supply by the selected energy resource, and in a range defined by and between the limits specified by the upper energy function and the lower energy function,

wherein, in the generating of the upper energy function by the demand prediction unit, energy is taken to be supplied to the device immediately after the occurrence of an energy consumption event and so as to replenish the device with the energy consumed in the energy consumption event.

15. The control loop as claimed in claim 14 comprising a processing unit for processing the energy consumption data predicted for the energy storage device in the given time-window and the schedule produced for the provision of power to the energy storage device in the given planning time-period, thereby to predict a future demand for energy by the energy storage device in another planning time-period.

16. The control loop as claimed in claim 14 comprising a database for storing the predicted energy consumption data and the produced power schedule.

17. The control loop as claimed in claim 14 wherein the demand prediction unit is configurable to respond to a trigger to initiate prediction of the energy demand, the trigger being one of an automated event and a user intervention event.

18. The control loop as claimed in claim 14 wherein the energy supply prediction unit is configurable to use at least a generation forecast, cost factors or a combination thereof for the prediction of energy supply by the selected energy resource.

19. The control loop as claimed in claim 14 wherein the energy supply prediction unit is configurable to use grid constraints for the prediction of energy supply by the selected energy resource when geographic information on the energy storage device is known.