Wireless management system for energy storage systems

• US 10,804,712 B2
• Filed: 10/26/2018
• Issued: 10/13/2020
• 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): Parihar, Suchin
• Application Number:
  US16/172,576
• Publication Number:
  US 20190131814A1
• Time in Patent Office: 718 Days
• Field of Search: 320108
• 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 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 7/00032 characterised by data exchange
• 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

The wireless management system for energy storage systems includes a plurality of smart cells arranged into a two-dimensional array and a plurality of distributed management units. The smart cells and management units communicate with each other wirelessly via capacitive coupling (not radio). The communication links have extremely short range (typically under 3 mm), are relatively directional, and are electronically-steerable in the plane of the array. The smart cells may also include at least one power resistor and switch for passive cell balancing. The circuitry in the smart cells is typically incorporated into a flexible sheet that wraps around the energy storage device like a label. This system is extremely reliable because it is massively redundant, fault tolerant, and eliminates the wires used in conventional monitoring systems.

Claims

1. An energy storage system, comprising:

a positive terminal and a negative terminal for charging and discharging the energy storage system;

a plurality of smart cells arranged into a two-dimensional array and coupled to the positive and negative terminals, each smart cell comprising;

at least one energy storage device,

a plurality of conductive plates surrounding the at least one energy storage device in the plane of the two-dimensional array for communicating with multiple other smart cells within the array via a capacitive coupling, and

a cell controller circuit producing data related to the state of the at least one energy storage device and operable to receive a direction code and, in response to receiving the direction code, selecting at least one plate from the plurality of conductive plates and utilizing the at least one selected plate to communicate the data; and

at least one management unit for sending the direction code to the plurality of smart cells and receiving the data from the smart cells via said capacitive coupling.

2. The energy storage system of claim 1, including a management network, wherein each management unit includes a network interface coupled to the management network for communicating with at least one other management unit within the energy storage system.

3. The energy storage system of claim 1, wherein the at least one of the management unit is in communication with a device for charging the energy storage system.

4. The energy storage system of claim 1, wherein each smart cell further includes at least one resistor coupled to the at least one energy storage device via at least one electronically controlled switch for passive balancing of the at least one energy storage device.

5. The energy storage system of claim 1, wherein the data produced by the cell controller circuit is selected from the group consisting of a voltage across at least one energy storage device, a temperature of at least one energy storage device, and an internal pressure of the least one energy storage device.

6. A smart cell for storing and providing energy in an energy storage system, comprising:

a positive terminal and a negative terminal for connecting the smart cell to at least the energy storage system;

at least one energy storage device coupled to the positive terminal and the negative terminal;

a plurality of conductive plates surrounding the at least one energy storage device for communicating with at least one other smart cell in the energy storage system via a capacitive coupling; and

a cell controller circuit for drawing power from the positive terminal and the negative terminal and producing data related to the state of the at least one energy storage device, the cell controller operable to receive a direction code and, in response to receiving the direction code, selecting at least one plate from the plurality of conductive plates and utilizing the at least one selected plate to communicate the data.

7. The smart cell of claim 6, wherein the cell controller circuit is operable to select a pair of the plurality of conductive plates for differential signaling.

8. The smart cell of claim 6, further including at least one resistor coupled to the at least one energy storage device via at least one electronically controlled switch for passive balancing of the at least one energy storage device.

9. A flexible circuit assembly for a smart cell that includes at least one energy storage device, the flexible circuit assembly comprising:

a flexible substrate adapted to wrap around the at least one energy storage device;

a plurality of conductive plates distributed across the flexible substrate for communication via a capacitive coupling;

a positive node and a negative node for coupling to the at least one energy storage device; and

a cell controller circuit for drawing power from the positive node and the negative node and producing data related to the state of the at least one energy storage device, the cell controller operable to receive a direction code and, in response to receiving the direction code, selecting at least one plate from the plurality of conductive plates and utilizing the at least one selected plate to communicate the data.

10. The flexible circuit assembly of claim 9, including at least one resistor and at least one electronically controlled switch coupled to the positive and negative nodes for passive cell balancing.

11. An integrated circuit for controlling a smart cell having at least one energy storage device and a plurality of conductive plates for communication with multiple other smart cells within an energy storage system via a capacitive coupling, the integrated circuit comprising:

a data acquisition circuit for producing data related to the state of the at least one energy storage device;

a switch matrix for selecting at least one plate from the plurality of conductive plates;

at least one driver circuit for sending data via the at least one selected plate;

at least one receiver circuit for receiving data via the at least one selected plate; and

a logic circuit for controlling the switch matrix and transferring data among the data acquisition circuit, the at least one driver circuit, and the at least one receiver circuit.

12. The integrated circuit of claim 11, wherein the logic circuit further includes at least one configuration register for storing at least one direction code that determines which of the plurality of conductive plates are selected by the switch matrix.

13. The integrated circuit of claim 12, wherein the selected at least one plate comprises at least a pair of conductive plates suitable for differential signaling.

14. The integrated circuit of claim 11, wherein the logic circuit further includes at least one status bit with a state determined by a polarity of a received differential signal.

15. The integrated circuit of claim 11, further including at least one electronically-controlled switch for controlling a current flow through at least one resistor for passive balancing of the least one energy storage device.

16. The integrated circuit of claim 11, further including a nonvolatile memory for storing information selected from the group consisting of a manufacturer identification number, a serial number, a date code, and a calibration data related to the data acquisition circuit.

17. The integrated circuit of claim 12, wherein the logic circuit further includes at least one timer for resetting the at least one configuration register to a predefined default state in response to an absence of any received data for a predefined time interval.

18. The integrated circuit of claim 15, wherein the logic circuit further includes at least one timer for automatically turning off the at least one electronically-controlled switch after a predefined time interval.

19. A management unit for monitoring and controlling a plurality of smart cells in an energy storage system, comprising:

a plurality of conductive plates for communicating with at least one of the plurality of smart cells via a capacitive coupling;

at least one driver circuit for sending commands to at least one of the plurality of smart cells via the conductive plates;

a least one receiver circuit for receiving data from at least one of the plurality of smart cells via the conductive plates;

a network interface for communicating with other managements unit within the energy storage system; and

a logic circuit for conveying information among the network interface, the at least one driver circuit, and the at least one receiver circuit.

20. The management unit of claim 19, including a power supply circuit for providing power to the at least one driver circuit, the at least one receiver circuit, and the logic circuit, the power supply adapted to receive power from at least one source selected from the group consisting of the network interface and the energy storage system.