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EP-4741222-A1 - POWER-ON METHOD OF BATTERY SYSTEM, BATTERY SYSTEM, AND ELECTRIC DEVICE

EP4741222A1EP 4741222 A1EP4741222 A1EP 4741222A1EP-4741222-A1

Abstract

A power-on method of a battery system, a battery system, and an electric device, capable of improving the battery swapping performance of the battery system. The battery system comprises a plurality of battery swapping units connected in parallel, wherein each battery swapping unit comprises a battery and a first battery management unit thereof, and the battery system further comprises second battery management units connected to the first battery management units in the plurality of battery swapping units. The power-on method is executed by the second battery management units. The power-on method comprises: receiving a first power-on signal sent by a vehicle control unit; and in response to the first power-on signal, sending to the first battery management unit a second power-on signal, wherein the second power-on signal is used for instructing each first battery management unit to control the corresponding battery swapping unit to perform high-voltage power-on.

Inventors

  • WU, KAI
  • YANG, Zhengxing
  • CHAN, Libing

Assignees

  • Contemporary Amperex Technology Co., Limited

Dates

Publication Date
20260513
Application Date
20240205

Claims (20)

  1. A power-on method for a battery system, wherein the battery system comprises a plurality of battery swapping units connected in parallel, wherein each battery swapping unit comprises a battery and a first battery management unit of the battery, the battery system further comprises a second battery management unit connected to the first battery management units in the plurality of battery swapping units, the power-on method is performed by the second battery management unit, and the power-on method comprises: receiving a first power-on signal sent by a vehicle control unit; and in response to the first power-on signal, sending a second power-on signal to the first battery management unit, wherein the second power-on signal is used to instruct the first battery management unit to control a corresponding battery swapping unit to perform high-voltage power-on.
  2. The power-on method according to claim 1, wherein the power-on method further comprises: determining a number of the plurality of battery swapping units; wherein sending the second power-on signal to the first battery management unit comprises: in a case where the number of the plurality of battery swapping units is equal to a preset number, sending the second power-on signal to the first battery management unit.
  3. The power-on method according to claim 2, wherein determining the number of the plurality of battery swapping units comprises: sending an encoding signal to a first battery management unit of a first battery swapping unit among the plurality of battery swapping units, wherein the encoding signal is used to be sequentially transmitted among the first battery management units in the plurality of battery swapping units, so as to sequentially encode the plurality of battery swapping units; receiving an encoding result sent by a first battery management unit of a last battery swapping unit among the plurality of battery swapping units; and determining, based on the encoding result, the number of the plurality of battery swapping units.
  4. The power-on method according to any one of claims 1 to 3, wherein sending the second power-on signal to the first battery management unit comprises: determining at least one battery swapping unit to be powered on among the plurality of battery swapping units; and sending the second power-on signal to a first battery management unit in the at least one battery swapping unit.
  5. The power-on method according to claim 4, wherein determining the at least one battery swapping unit to be powered on among the plurality of battery swapping units comprises: determining, based on voltages of the plurality of battery swapping units, the at least one battery swapping unit to be powered on among the plurality of battery swapping units.
  6. The power-on method according to claim 5, wherein determining, based on the voltages of the plurality of battery swapping units, the at least one battery swapping unit to be powered on among the plurality of battery swapping units comprises: in a case where a voltage difference between a highest-voltage battery swapping unit and a lowest-voltage battery swapping unit among the plurality of battery swapping units is greater than or equal to a voltage threshold, determining that the at least one battery swapping unit comprises a battery swapping unit having a voltage difference from the highest-voltage battery swapping unit less than the voltage threshold.
  7. The power-on method according to claim 5 or 6, wherein determining, based on the voltages of the plurality of battery swapping units, the at least one battery swapping unit to be powered on among the plurality of battery swapping units comprises: in a case where the voltage difference between the highest-voltage battery swapping unit and the lowest-voltage battery swapping unit among the plurality of battery swapping units is less than or equal to the voltage threshold, determining that the at least one battery swapping unit comprises the plurality of battery swapping units.
  8. The power-on method according to any one of claims 4 to 7, wherein the battery swapping unit further comprises a slave high-voltage box connected to the battery, and the slave high-voltage box comprises a first relay unit, wherein the second power-on signal is specifically used to instruct the first battery management unit to control a corresponding first relay unit to close.
  9. The power-on method according to claim 8, wherein the battery system further comprises a master high-voltage box, the slave high-voltage box is connected to the master high-voltage box via a pluggable electrical connector, the master high-voltage box comprises a second relay unit, and the power-on method further comprises: controlling the second relay unit to close after the first relay unit in the at least one battery swapping unit is closed.
  10. The power-on method according to claim 9, wherein the power-on method further comprises: sending a power-on completion signal to the vehicle control unit after the second relay unit is closed.
  11. The power-on method according to any one of claims 1 to 10, wherein the power-on method further comprises: sending information on an allowable power of the battery system, wherein the allowable power of the battery system is a sum of allowable powers of the plurality of battery swapping units.
  12. The power-on method according to any one of claims 1 to 11, wherein the power-on method further comprises: receiving a wake-up signal; and performing, based on the wake-up signal, low-voltage power-on on the second battery management unit.
  13. A battery system, comprising: a plurality of battery swapping units connected in parallel, wherein each battery swapping unit comprises a battery and a slave high-voltage box connected to the battery, and the slave high-voltage box comprises a first battery management unit of the battery; and a master high-voltage box, wherein the slave high-voltage box is connected to the master high-voltage box via a pluggable electrical connector, and the master high-voltage box comprises a second battery management unit connected to the first battery management units in the plurality of battery swapping units.
  14. The battery system according to claim 13, wherein the electrical connector comprises a high-voltage interface and a low-voltage interface, a high-voltage line in the slave high-voltage box is connected to a high-voltage line in the master high-voltage box via the high-voltage interface, and a low-voltage line in the slave high-voltage box is connected to a low-voltage line in the master high-voltage box via the low-voltage interface.
  15. The battery system according to claim 13 or 14, wherein the master high-voltage box and/or the slave high-voltage box further comprises an insulation detector, the insulation detector is configured to detect insulation impedance to ground of a high-voltage bus, and the insulation detector in the master high-voltage box and the insulation detector in the slave high-voltage box are configured to be prevented from being enabled simultaneously.
  16. The battery system according to claim 15, wherein in a case where the battery system is assembled in an electric apparatus, the insulation detector in the master high-voltage box is configured to be enabled, and the insulation detector in the slave high-voltage box is configured to be prevented from being enabled; and/or in a case where the battery system is charged in a battery swapping station, the insulation detector in the slave high-voltage box is configured to be enabled.
  17. The battery system according to any one of claims 13 to 16, wherein the master high-voltage box and/or the slave high-voltage box further comprises a high-voltage detection circuit, and the high-voltage detection circuit is configured to detect a voltage of the high-voltage bus and/or a voltage across a relay.
  18. The battery system according to any one of claims 13 to 17, wherein the slave high-voltage box further comprises a main positive relay connected to a positive electrode of the slave high-voltage box, and/or a main negative relay connected to a negative electrode of the slave high-voltage box.
  19. The battery system according to any one of claims 13 to 18, wherein the slave high-voltage box comprises at least one high-voltage connector and at least one low-voltage connector, the high-voltage connector comprises a main loop connector for connecting the master high-voltage box and a branch connector for connecting the battery on each branch, and the low-voltage connector comprises an external low-voltage connector for connecting the master high-voltage box and a low-voltage input/output connector for connecting a cell sampling circuit of the battery on each branch.
  20. The battery system according to claim 19, wherein the electrical connector is arranged on an outer frame of the battery swapping unit, the high-voltage interface on the electrical connector is configured to connect to the main loop connector of the slave high-voltage box, and the low-voltage interface on the electrical connector is configured to connect to the external low-voltage connector of the slave high-voltage box.

Description

The present application claims priority to Chinese Patent Application No. 202310936376.2, filed with China National Intellectual Property Administration on July 27, 2023 and entitled "POWER-ON METHOD FOR BATTERY SYSTEM, BATTERY SYSTEM, AND ELECTRIC APPARATUS", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present application relates to the field of batteries, and in particular, to a power-on method for a battery system, a battery system, and an electric apparatus. BACKGROUND A battery swapping station enables rapid battery swapping for an electric vehicle. However, with the increasing number of battery packs in the electric vehicle and more flexible distribution positions of such battery packs, how to improve the battery swapping performance of the electric vehicle has become an urgent problem to be addressed. SUMMARY Embodiments of the present application provide a power-on method for a battery system, a battery system, and an electric apparatus, which can improve the battery swapping performance of the battery system. In a first aspect, a power-on method for a battery system is provided. The battery system includes a plurality of battery swapping units connected in parallel, where each battery swapping unit includes a battery and a first battery management unit of the battery, the battery system further includes a second battery management unit connected to the first battery management units in the plurality of battery swapping units, the power-on method is performed by the second battery management unit, and the power-on method includes: receiving a first power-on signal sent by a vehicle control unit; and in response to the first power-on signal, sending a second power-on signal to the first battery management unit, where the second power-on signal is used to instruct the first battery management unit to control a corresponding battery swapping unit to perform high-voltage power-on. The battery system according to the present application includes a plurality of battery swapping units, each battery swapping unit includes a battery and a corresponding first battery management unit, and the first battery management units in the plurality of battery swapping units are all connected to the second battery management unit. Therefore, the plurality of battery swapping units do not need to be bound for use, allowing only a portion of the battery swapping units to be swapped and charged. This supports the mixed use of the battery swapping units, thereby resulting in high battery swapping efficiency and facilitating the construction and operation of the battery swapping station. When the battery system is subject to the high-voltage power-on, the second battery management unit may receive the first power-on signal sent by the vehicle control unit, and send, in response to the first power-on signal, the second power-on signal to the first battery management unit, such that the first battery management unit controls a corresponding battery swapping unit to perform high-voltage power-on, thereby effectively achieving the high-voltage power-on of the battery system. In a possible implementation, the power-on method further includes: determining a number of the plurality of battery swapping units, where sending the second power-on signal to the first battery management unit includes: in a case where the number of the plurality of battery swapping units is equal to a preset number, sending the second power-on signal to the first battery management unit. Determining whether the number of the battery swapping units is equal to the preset number before the high-voltage power-on can reduce the risks caused by problems such as failure of the battery swapping units and improve the reliability of the power-on process of the battery system. In a possible implementation, determining the number of the plurality of battery swapping units includes: sending an encoding signal to a first battery management unit of a first battery swapping unit among the plurality of battery swapping units, where the encoding signal is used to be sequentially transmitted among the first battery management units in the plurality of battery swapping units, so as to sequentially encode the plurality of battery swapping units; receiving an encoding result sent by a first battery management unit of a last battery swapping unit among the plurality of battery swapping units; and determining, based on the encoding result, the number of the plurality of battery swapping units. In this implementation, the encoding signal is sent to the first battery management unit of the first battery swapping unit, and the encoding signal is sequentially delivered among the plurality of battery swapping units until the first battery management unit of the last battery swapping unit receives the encoding signal, so as to encode the plurality of battery swapping units. The second battery management unit receives the encoding resul