Ultra-fast charge profile for an electric vehicle

• US 10,682,920 B2
• Filed: 12/19/2017
• Issued: 06/16/2020
• Est. Priority Date: 12/19/2017
• Status: Active Grant

• Current Assignee: NIO Technology Company Limited (Shanghai Anbin Technology Co., Ltd.)
• Original Assignee: Nio Usa Inc.
• Inventors: Smith, Alexander J.
• Primary Examiner(s): Tso, Edward
• Application Number:
  US15/847,168
• Publication Number:
  US 20190184836A1
• Time in Patent Office: 910 Days
• Field of Search: 320124, 320125, 320132, 320134, 320136, 320137, 320149, 320160, 320162
• 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 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: H02J 13/00 Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 13/00017 using optical fiber
• CPC Class Codes: H02J 13/00024 by means of mobile telephony
• CPC Class Codes: H02J 13/00026 involving a local wireless network, e.g. Wi-Fi, ZigBee or Bluetooth
• CPC Class Codes: H02J 13/00028 involving the use of Internet protocols
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• 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 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 40/124 : using wired telecommunication networks or data transmission busses

Abstract

Battery charging systems and the operations thereof are provided. The battery charging systems provide fast charging. The battery charging systems include a charging unit, a battery, a battery management system, and a number of sensors and battery monitors. The battery includes one or more cells. The battery charging systems include a fast-charge profile including a number of stages.

Claims

1. A method of rapidly charging a battery, the method comprising the steps of:

determining, by a battery management system, a voltage limit of a battery cell;

instructing, by the battery management system, a battery charging unit to apply increasing current to the battery cell;

determining, by the battery management system, that the current has reached a maximum current level;

instructing, by the battery management system, the battery charging unit to apply the maximum current level;

determining, by the battery management system, that a voltage level of the battery cell exceeds a voltage limit of the battery cell;

instructing, by the battery management system, the battery charging unit to apply decreasing current to a battery current level while keeping a voltage level of the battery cell at or near a constant level;

determining, by the battery management system, that a target state of charge of the battery cell has been reached based on a measurement of a resistance level of the battery cell;

instructing, by the battery management system, the battery charging unit to cease applying current;

determining, by the battery management system, that the battery cell has equalized;

instructing, by the battery management system, the battery charging unit to resume charging;

determining, by the battery management system, that the battery cell has reached an optimum voltage level for the battery cell; and

instructing, by the battery management system, the battery charging unit to cease charging.

2. The method of claim 1, wherein the battery management system estimates an active resistance of the battery cell.

3. The method of claim 1, wherein the step of instructing, by the battery management system, the battery charging unit to apply increasing current to the battery cell further comprises instructing, by the battery management system, the battery charging unit to apply increasing current to the battery cell at a slow ramp rate.

4. The method of claim 1, wherein the step of instructing the battery charging unit to resume charging further comprises instructing the battery charging unit to resume charging at a lower rate.

5. The method of claim 4, wherein the lower rate comprises following a constant current protocol with a lower target voltage.

6. The method of claim 5, wherein the lower target voltage comprises the optimum voltage level for the battery cell.

7. The method of claim 1, wherein cell degradation is minimized.

8. A battery management system, comprising:

a circuit for receiving data from a battery comprising a battery cell; and

a circuit for communicating with a charging unit;

wherein, during a first charging stage, the battery management system;

determines a voltage limit of the battery cell;

instructs a battery charging unit to apply increasing current to the battery cell;

determines that the current has reached a maximum current level;

instructs the battery charging unit to apply the maximum current level;

determines that a voltage level of the battery cell exceeds a voltage limit of the battery cell;

instructs the battery charging unit to apply decreasing current to a battery current level while keeping the voltage level of the battery cell at or near a constant level;

determines that a target state of charge of the battery cell has been reached based on a measurement of a resistance level of the battery cell;

instructs the battery charging unit to cease applying current;

determines that the battery cell has equalized;

instructs the battery charging unit to resume charging;

determines that the battery cell has reached an optimum voltage level for the battery cell; and

instructs the battery charging unit to cease charging.

9. The battery management system of claim 8, wherein the battery management system estimates an active resistance of the battery cell.

10. The battery management system of claim 8, wherein the step of instructing, by the battery management system, the battery charging unit to apply increasing current to the battery cell further comprises instructing, by the battery management system, the battery charging unit to apply increasing current to the battery cell at a slow ramp rate.

11. The battery management system of claim 8, wherein the step of instructing the battery charging unit to resume charging further comprises instructing the battery charging unit to resume charging at a lower rate.

12. The battery management system of claim 11, wherein the lower rate comprises following a constant current protocol with a lower target voltage.

13. The battery management system of claim 12, wherein the lower target voltage comprises the optimum voltage level for the battery cell.

14. The battery management system of claim 9, wherein cell degradation is minimized.

15. A method of rapidly charging a lithium ion battery cell, the method comprising:

applying, to the battery cell, increasing current based on a voltage limit of the battery cell;

applying, to the battery cell, a constant current, wherein the constant current is at or near a maximum current level for the battery cell;

when a voltage level of the battery cell exceeds a voltage limit of the battery cell, applying decreasing current to a battery current level while keeping a voltage level of the battery cell at or near a constant level;

when a target state of charge of the battery cell has been reached based on a measurement of a resistance level of the battery cell, ceasing to apply current to the battery cell;

when the battery cell has equalized, resuming charging; and

when the battery cell has reached an optimum voltage level for the battery cell, ceasing charging.

16. The method of claim 15, further comprising determining an estimated active resistance of the battery cell.

17. The method of claim 15, wherein the step of applying increasing current to the battery cell further comprises causing a battery charging unit to apply increasing current to the battery cell at a slow ramp rate.

18. The method of claim 15, wherein the step of resuming charging further comprises causing a battery charging unit to resume charging at a lower rate.

19. The method of claim 18, wherein the lower rate comprises following a constant current protocol with a lower target voltage.

20. The method of claim 19, wherein the lower target voltage comprises the optimum voltage level for the battery cell.