Systems and methods for battery management

• US 9,496,730 B2
• Filed: 07/28/2011
• Issued: 11/15/2016
• Est. Priority Date: 09/02/2010
• Status: Active Grant

• Current Assignee: Volvo Battery Solutions LLC
• Original Assignee: Proterra AG
• Inventors: Gallegos, Nicky G., Walker, Michael
• Primary Examiner(s): Rodas, Richard Isla
• Assistant Examiner(s): DIBENEDETTO, MICHAEL N
• Application Number:
  US13/193,278
• Publication Number:
  US 20120105001A1
• Time in Patent Office: 1,937 Days
• Field of Search: 320/104, 320/116
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 3/0092 with use of redundant elements for safety purposes
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/62 in response to charging parameters, e.g. current, voltage or electrical charge
• CPC Class Codes: B60L 53/66 Data transfer between charging stations and vehicles
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/14 Preventing excessive discharging
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: B60L 58/26 : by cooling
• 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 10/0525 : Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/441 : for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H02J 7/0016 : using shunting, discharge or bypass circuits
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles

Abstract

A battery management system includes several subsystem blocks, an Energy Storage Master unit, and several battery pack systems. The Energy Storage Master may interface with the Vehicle Master Controller by way of CAN or other communication method to an External Charger. Each battery module within a battery pack may include a Local Module Unit which may communicate with a Pack Master. The Pack Master may communicate with and may be controlled by the Energy Storage Master. Thus, there is a processor to monitor groups of battery cells, a second processor to collect further information about the cell groups, and a third module that takes high-level information from each cell group processor to process and pass on to other vehicle controllers or charger controllers. An integrated BMS may enable cell monitoring, temperature monitoring, cell balancing, string current monitoring, and charger control integration.

Claims

1. A battery management system for a battery assembly of an electric vehicle, the battery assembly including a plurality of battery strings connected in parallel, wherein (a) each battery string includes a plurality of battery packs, (b) each battery pack includes a plurality of battery modules packaged together in an enclosure, and (c) each battery module includes multiple battery cells packaged together in a module housing, comprising:

a module control unit associated with each battery module, wherein the module control unit is a printed circuit board attached directly to each battery module, and positioned within the module housing of the battery module, wherein the module control unit associated with each battery module is separate from the module control unit associated with another battery module, and wherein each module control unit is configured to detect at least a voltage, a current, a humidity, and a temperature of a plurality of battery cells of the corresponding battery module;

a Serial Peripheral Interface (SPI) isolation board attached to each module control unit; and

a pack control unit associated with each battery pack, wherein each pack control unit is configured to perform cell balancing of the battery cells of the corresponding battery pack based on the voltages and temperatures detected by the module control units of the battery pack,

wherein the module control units and the pack control unit of the battery pack are connected together using a Serial Peripheral Interface (SPI) bus, and wherein the SPI isolation board attached to each module control unit isolates SPI signals from the module control unit to the pack control unit.

2. The system of claim 1, wherein the electric vehicle is an electric bus, and wherein at least one battery pack of the plurality of battery packs is positioned under a floor of the bus.

3. The system of claim 2, wherein the pack control unit is operably coupled to an external charger of the electric vehicle.

4. The system of claim 1, wherein ten battery cells form a battery module, and eight battery modules form a battery pack.

5. The system of claim 1, further including an energy storage master control unit coupled to each pack control unit of the battery assembly, the energy storage master control unit being configured to monitor a state of health of the battery cells of the battery assembly and disconnect a battery string of the plurality of battery strings from service based on the state of health of a battery cell in the battery string to allow the vehicle to continue operating using the remaining battery strings.

6. The system of claim 1, wherein the pack control unit is configured to balance the multiple battery cells of the battery pack by buffering energy from a plurality of battery cells of the multiple battery cells into a capacitor and then transferring the buffered energy into one or more battery cells of the multiple battery cells.

7. The system of claim 1, wherein the multiple battery cells of each battery module are connected in series.

8. The system of claim 1, wherein the pack control unit is configured to balance the battery cells of a battery pack by discharging a battery cell into a resistor.

9. The system of claim 1, wherein the module control units and the pack control unit of a battery pack are connected together in series using the SPI bus.

10. The system of claim 1, wherein the module housing of each battery module includes electrical connectors to separably electrically connect the battery module to other battery modules of a battery pack.

11. The system of claim 1, wherein the module housing of each battery module includes a heat sink.

12. The system of claim 11, wherein the heat sink is an aluminum heat sink.

13. The system of claim 1, wherein the enclosure of each battery pack is an IP67 compliant housing, and wherein each enclosure includes one or more IP67 rated electrical connectors that provide the only electrical connections to contents of the enclosure.

14. A battery management system for an electric vehicle, comprising:

a battery assembly including;

a plurality of battery strings connected in parallel;

a plurality of battery packs in each battery string of the plurality of battery strings, wherein each battery pack of the plurality of battery packs includes an enclosure which is IP67 compliant, and wherein each enclosure includes one or more IP67 rated electrical connectors that provide the only electrical connections to contents of the enclosure;

a plurality of battery modules packaged within the enclosure of each battery pack, wherein each battery module of the plurality of battery modules includes a housing to provide isolation and cooling to contents of the housing, and wherein the housing includes one or more electrical connectors to provide separable electrical connection to contents of the housing; and

a plurality of battery cells packaged within the housing of each battery module;

a plurality of module control units, wherein each module control unit (a) is a printed circuit board attached to a single battery module of the plurality of battery modules and (b) is configured to detect at least a voltage, a current, a humidity, and a temperature of the plurality of battery cells of the battery module, and wherein the module control unit attached to each battery module is separate from the module control unit attached to another battery module;

a plurality of Serial Peripheral Interface (SPI) isolation boards, wherein each SPI isolation board is attached to a single module control unit of the plurality of module control units; and

a plurality of pack control units, wherein each pack control unit is associated with a single battery pack of the plurality of battery packs and is configured to perform cell balancing of the battery cells of the battery pack based on the voltages and temperatures detected by the module control units of the battery pack,

wherein the module control units and the pack control unit of each battery pack are connected together using a Serial Peripheral Interface (SPI) bus, and wherein the SPI isolation board attached to each module control unit isolates SPI signals from the module control unit to the pack control unit.

15. The system of claim 14, wherein the electric vehicle is an electric bus, and wherein the plurality of battery packs are positioned under a floor of the bus.

16. The system of claim 14, further including an energy storage master control unit electrically connected to the plurality of packs control units, the energy storage master control unit being configured to monitor a state of health of the battery cells of the battery assembly and disconnect a battery string of the plurality of battery strings from service based on the state of health of a battery cell in the battery string to allow the vehicle to continue operating using the remaining battery strings.

17. The system of claim 14, wherein the pack control unit of each battery pack is configured to balance the battery cells of the battery pack by buffering energy from some battery cells into a capacitor and then transferring the buffered energy into other battery cells.

18. The system of claim 14, wherein the housing of each battery module includes a heat sink.

19. The system of claim 18, wherein the heat sink is an aluminum heat sink.