Method for management of energy storage systems, and related method of operation for smart energy storage cells

• US 10,790,549 B2
• Filed: 10/26/2018
• Issued: 09/29/2020
• Est. Priority Date: 10/26/2017
• Status: Active Grant

• Current Assignee: Sunfield Semiconductor, Inc.
• Original Assignee: Sunfield Semiconductor, Inc.
• Inventors: Robbins, Steven Andrew
• Primary Examiner(s): Rossoshek, Helen
• Application Number:
  US16/172,583
• Publication Number:
  US 20190131802A1
• Time in Patent Office: 704 Days
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 2010/4278 Systems for data transfer from batteries, e.g. transfer of battery parameters to a controller, data transferred between battery controller and main controller
• CPC Class Codes: H02J 13/0003 for DC networks
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H04B 5/22 Capacitive coupling
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method of managing an energy storage system that includes a plurality of smart energy storage cells, and a related method of operation for said smart cells. The cells are arranged into a two-dimensional array, and at least one management unit for controlling and monitoring the smart cells is coupled to the array. The smart cells and management units engage in wireless communication that has relatively short range and is relatively directional, with the direction being electronically-steerable in the plane of the array. The management method assigns direction codes to each smart cell which the cells utilize to steer the directions of their communication links, thereby organizing the smart cells into a plurality of serially-linked communication networks. The methods include steps for automatically determining the size and arrangement of the array, including the orientation of each smart cell. The methods also include steps for automatically reorganizing the network links in response to any cell or management unit failing to communicate, thereby making the energy storage system highly fault-tolerant and extremely reliable.

Claims

1. A method of managing an electrical energy storage system, comprising steps of:

operating a plurality of smart cells in either a link mode or a termination mode within a two-dimensional array, with each smart cell communicating wirelessly with another smart cell in a manner that is relatively directional, the direction being electronically-steerable in a plane of the two-dimensional array;

organizing the smart cells into a plurality of chains, each chain being a serially-linked wireless network having a first smart cell therein being in communication with a management unit for controlling and monitoring the smart cells and a second smart cell therein operating as a termination cell, wherein all smart cells in the respective chain other than the termination cell operate as link cells, the organizing step including the steps of;

assigning an up-direction code to each smart cell in each respective chain for at least sending and receiving information along the respective chain in a direction of the management unit; and

assigning a down-direction code to each smart cell other than the termination cell for at least sending and receiving information along the respective chain in a direction of the termination cell; and

operating the energy storage system in a repetitive loop, comprising the steps of;

collecting a set of data produced by each of the plurality of smart cells in each of the plurality of chains, wherein each smart cell sends its set of data up chain, and each of the link cells relays the data set from other down-chain smart cells up chain; and

analyzing the set of data from each of the plurality of smart cells to determine the overall status of the energy storage system.

2. The method of claim 1, wherein the organizing step includes the steps of planning a floor plan of the plurality of chains and building the chains in accordance with the floor plan.

3. The method of claim 2, wherein at least one of the management units includes a nonvolatile memory and the planning step includes the step of reading a predetermined floor plan from the nonvolatile memory.

4. The method of claim 2, wherein the planning step includes adding one or more new smart cells positioned within a communication range of the termination cell in one of the plurality of chains, including the steps of:

scanning for the one or more new smart cell within the communication range of the termination cell;

reporting a direction code for each of the one or more new smart cells up the respective chain to the respective management unit;

adding the new smart cell to the floor plan;

selecting one of the one or more new smart cells for concatenation to the respective chain;

sending a direction code for the selected new smart cell from the management unit down the chain to the termination cell;

setting a down-direction of the termination cell to the direction code received by the termination cell from the management unit;

sending a join command from the termination cell to the selected new smart cell;

changing the termination cell to one of the link cells;

setting an up-direction of the selected new smart cell to point in the direction from which it received the join command; and

setting the selected new smart cell as the termination cell.

5. The method of claim 4, wherein the planning step reiterates the steps for adding one or more new smart cells until at least every smart cell on a perimeter of the array is included in the floor plan.

6. The method of claim 4, including the step of mapping a position of the one or more new smart cells in a set of estimated Cartesian coordinates.

7. The method of claim 6, wherein the planning step includes steps of:

utilizing the set of estimated Cartesian coordinates for the one or more new smart cells to select a best-fit grid from a group consisting of a rectangular grid and a hexagonal grid; and

correcting the set of estimated Cartesian coordinates of at least one of the one or more new smart cells to coincide with coordinates of the closest grid location.

8. The method of claim 4, wherein in response to any of the plurality of smart cells or the management unit being uncommunicative for a predetermined time limit, performing a recovery step comprising the steps of:

exiting from the repetitive loop;

removing the uncommunicative smart cell or the uncommunicative management unit from the floor plan;

producing a modified floor plan;

repeating the planning step for at least one chain; and

returning to the repetitive loop.

9. The method of claim 1, wherein the repetitive loop includes the step of addressing a command to a selected smart cell within one of the plurality of chains.

10. The method of claim 9, including the step of charge balancing one or more of the plurality of the smart cells with charge balancing circuitry within the smart cells.

11. The method of claim 10, including the steps of selecting one or more of the plurality of the smart cells to have their charge balancing activated or deactivated and sending an activation signal or a deactivation signal to the selected smart cells.

12. The method of claim 9, wherein the addressing step includes steps for:

sending an address and a command from the management unit down one of the plurality of chains;

forwarding the address and the command, wherein when the address is not equal to a predetermined value at the respective smart cell, the smart cell responds by;

updating the address by adding a predetermined offset, and

sending the updated address and the command down the chain; and

executing the command in the smart cell that receives the address equal to the predetermined value.

13. The method of claim 9, wherein each smart cell maintains an address flag setting with at least an addressed state and an unaddressed state, wherein the addressing step further includes the steps of:

sending an address from the management unit down one of the plurality of chains;

forwarding the address, wherein when the address is not equal to a predetermined value at the respective smart cell, the smart cell responds by;

setting its address flag to the unaddressed state;

updating the address by adding a predetermined offset; and

sending the updated address down the chain;

setting the address flag to the addressed state in the smart cell that receives an address equal to the predetermined value;

sending a command from the management unit down the chain;

forwarding the command, wherein each smart cell that has its address flag set to the unaddressed state sends the command down the chain; and

executing the command in the smart cell that has its address flag set to the addressed state.

14. The method of claim 1, further including the steps of:

sending a predetermined initial cell count up the chain;

forwarding the cell count, wherein each smart cell that receives the cell count responds by;

updating the cell count by adding a predetermined offset, and

sending the updated cell count up the chain; and

receiving a final cell count in the management unit.

15. The method of claim 1, including the step of changing one of the link cells to the termination cell in response to the changed link cell not receiving communications from the down direction for a predetermined time limit.

16. The method of claim 1, wherein at least one management unit is in communication with a charge controller and the step of analyzing the data includes notifying the charge controller in response to the energy storage state of any smart cell reaching or exceeding a predetermined limit.

17. A method of managing an electrical energy storage system, the system comprising a plurality of smart cells operable in either a link mode or a termination mode and arranged into a two-dimensional array, each smart cell adapted to communicate wirelessly in a manner that is relatively directional with the direction being electronically-steerable in a plane of the two-dimensional array, the method comprising steps of:

organizing the smart cells into a plurality of chains, each chain being a serially-linked wireless network having a first smart cell therein being in communication with a management unit for controlling and monitoring the smart cells and a second smart cell therein operating as a termination cell, wherein all smart cells in the respective chain other than the termination cell operate as link cells, the organizing step including the steps of;

assigning an up-direction code to each smart cell in each respective chain for at least sending and receiving information along the respective chain in a direction of the management unit; and

assigning a down-direction code to each smart cell other than the termination cell for at least sending and receiving information along the respective chain in a direction of the termination cell;

planning a floor plan of the plurality of chains, comprising the steps of;

adding one or more new smart cells positioned within a communication range of the termination cell in one of the plurality of chains;

scanning for the one or more new smart cell within the communication range of the termination cell;

reporting a direction code for each of the one or more new smart cells up the respective chain to the respective management unit;

adding the new smart cell to the floor plan;

selecting one of the one or more new smart cells for concatenation to the respective chain;

sending a direction code for the selected new smart cell from the management unit down the chain to the termination cell;

setting a down-direction of the termination cell to the direction code received by the termination cell from the management unit;

sending a join command from the termination cell to the selected new smart cell;

changing the termination cell to one of the link cells;

setting an up-direction of the selected new smart cell to point in the direction from which it received the join command; and

setting the selected new smart cell as the termination cell;

building the chains in accordance with the floor plan; and

operating the energy storage system in a repetitive loop, comprising the steps of;

collecting a set of data produced by each of the plurality of smart cells in each of the plurality of chains, wherein each smart cell sends its set of data up chain, and each of the link cells relays the data set from other down-chain smart cells up chain; and

analyzing the set of data from each of the plurality of smart cells to determine the overall status of the energy storage system.

18. The method of claim 17, wherein at least one of the management units includes a nonvolatile memory and the planning step includes the step of reading a predetermined floor plan from the nonvolatile memory.

19. The method of claim 17, wherein the planning step reiterates the steps for adding one or more new smart cells until at least every smart cell on a perimeter of the array is included in the floor plan.

20. The method of claim 17, including the step of mapping a position of the one or more new smart cells in a set of estimated Cartesian coordinates.

21. The method of claim 20, wherein the planning step includes steps of:

utilizing the set of estimated Cartesian coordinates for the one or more new smart cells to select a best-fit grid from a group consisting of a rectangular grid and a hexagonal grid; and

correcting the set of estimated Cartesian coordinates of at least one of the one or more new smart cells to coincide with coordinates of the closest grid location.

22. The method of claim 17, wherein in response to any of the plurality of smart cells or the management unit being uncommunicative for a predetermined time limit, performing a recovery step comprising the steps of:

exiting from the repetitive loop;

removing the uncommunicative smart cell or the uncommunicative management unit from the floor plan;

producing a modified floor plan;

repeating the planning step for at least one chain; and

returning to the repetitive loop.

23. The method of claim 17, wherein the repetitive loop includes the step of addressing a command to a selected smart cell within one of the plurality of chains.

24. The method of claim 23, including the step of charge balancing one or more of the plurality of the smart cells with charge balancing circuitry within the smart cells.

25. The method of claim 24, including the steps of selecting one or more of the plurality of the smart cells to have their charge balancing activated or deactivated and sending an activation signal or a deactivation signal to the selected smart cells.

26. The method of claim 23, wherein the addressing step includes steps for:

sending an address and a command from the management unit down one of the plurality of chains;

forwarding the address and the command, wherein when the address is not equal to a predetermined value at the respective smart cell, the smart cell responds by;

updating the address by adding a predetermined offset, and

sending the updated address and the command down the chain; and

executing the command in the smart cell that receives the address equal to the predetermined value.

27. The method of claim 23, wherein each smart cell maintains an address flag setting with at least an addressed state and an unaddressed state, wherein the addressing step further includes the steps of:

sending an address from the management unit down one of the plurality of chains;

forwarding the address, wherein when the address is not equal to a predetermined value at the respective smart cell, the smart cell responds by;

setting its address flag to the unaddressed state;

updating the address by adding a predetermined offset; and

sending the updated address down the chain;

setting the address flag to the addressed state in the smart cell that receives an address equal to the predetermined value;

sending a command from the management unit down the chain;

forwarding the command, wherein each smart cell that has its address flag set to the unaddressed state sends the command down the chain; and

executing the command in the smart cell that has its address flag set to the addressed state.

28. The method of claim 17, further including the steps of:

sending a predetermined initial cell count up the chain;

forwarding the cell count, wherein each smart cell that receives the cell count responds by;

updating the cell count by adding a predetermined offset;

sending the updated cell count up the chain; and

receiving a final cell count in the management unit.

29. The method of claim 17, including the step of changing one of the link cells to the termination cell in response to the changed link cell not receiving communications from the down direction for a predetermined time limit.

30. The method of claim 17, wherein at least one management unit is in communication with a charge controller and the step of analyzing the data includes notifying the charge controller in response to the energy storage state of any smart cell reaching or exceeding a predetermined limit.