Hybrid battery system

Patent metadata

Field	Value
Publication number	US-11670954-B2
Application number	US-201716332431-A
Country	US
Kind code	B2
Filing date	Sep 13, 2017
Priority date	Sep 15, 2016
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

A stationary hybrid battery back-up system incorporates two different battery units that differ in terms of recharging efficiency, cycle life, power capability, depth of discharge threshold, temperature threshold, internal impedance threshold, charger rate efficiency and/or stand-by efficiency. The battery back-up system of the present invention comprises an auxiliary power supply that can be used to charge the first and second batteries and/or provide power to a load. When the operating voltage of the system drops, due to a power failure of a power source, the control system may couple the first and/or second battery unit to a load. The control system may have voltage threshold limits wherein it engages the first and second battery units to support the load demand. The first and second battery units may be charge by the auxiliary power supply when the operating voltage is above a threshold level.

First claim

What is claimed is:

1. A hybrid battery system for power storage in a power network comprising a power source and a load, comprising:
a battery system comprising:
a first rechargeable battery unit having a first battery chemistry; and
a second rechargeable battery unit having a second battery chemistry,
the first and second battery chemistries being different from each other;
a control system for selectively coupling the battery units of the battery system to the power network (a) for delivery of electrical energy from the battery system to the load during discharging, and (b) for receipt of electrical energy from the power source for charging of the battery system during charging;
a power supply voltage sensor for detecting an operating voltage of the power being delivered to the load from the power source,
the control system comprising logic for switching the control system between charging and discharging of the battery system based on the operating voltage being in a charging range or a discharging range, respectively;
wherein the control system further includes charging mode selection logic for selecting between modes of charging based on the operating voltage within the charging range, the modes including: (a) charging both said battery units simultaneously each at a predetermined charge rate when the operating voltage is above a first threshold, (b) charging the first battery unit at the predetermined charge rate thereof and the second battery unit at a decreased rate when the operating voltage is below the first charge threshold and above a second charge threshold, and (c) charging only the first battery unit at a decreased rate when the operating voltage is below the second charge threshold.

2. The system according to claim 1 , wherein the first battery unit has a higher power efficiency than the second battery unit, and the second battery unit has a higher energy efficiency than the first battery unit.

3. The system of claim 1 , wherein a threshold voltage separates the charging range from the discharging range.

4. The system of claim 3 , wherein the power source has an operative voltage range and the threshold charging voltage is about 50% of said operative voltage range.

5. The system of claim 1 , wherein the first charge threshold is above about 90% of the operative voltage range.

6. The system of claim 1 , wherein the second charge threshold is above about 70% of the operative voltage range.

7. The system according to claim 1 , wherein the control system further includes discharging mode selection logic for selecting between modes of discharging based on the operating voltage within the discharging range, the modes of discharging including: (a) discharging both said battery units simultaneously each at a predetermined rate when the operating voltage is below a second discharge threshold, (b) discharging the first battery unit at a predetermined rate thereof and the second battery unit at a decreased rate when the operating voltage is above the second discharge threshold and below a first discharge threshold, and (c) discharging only the first battery unit when the operating voltage is above the first discharge threshold.

8. The system of claim 7 , wherein the control system includes threshold event logic configured to switch from discharging the first battery unit to discharging the second battery unit in the event a first battery unit threshold event is detected, irrespective of the mode selected by the discharging mode selection logic.

9. The system of claim 8 , wherein the control system monitors a state of charge of the first battery unit and the state of charge falling below a level is the first battery unit threshold event.

10. The system of claim 9 , wherein the state of charge is determined by an impedance of the first battery unit.

11. The system of claim 8 , wherein the threshold event is when the impedance value of the first battery unit exceeds about 110% of the impedance of the first battery unit at maximum state of charge.

12. The system of claim 8 , wherein the threshold event is the first battery unit exceeding a threshold temperature for the first battery unit.

13. The system of claim 8 , wherein the threshold event is an environmental temperature of the first battery unit exceeding a threshold environmental temperature.

14. The system of claim 8 , wherein the threshold event is an environmental temperature of the first battery unit dropping below a threshold environmental temperature.

15. The system of claim 8 , wherein the threshold event is a power demand exceeding a power capability threshold of the first battery unit.

16. The system of claim 15 , wherein the power demand is greater than about 90% of a power capability of the first battery unit.

17. The system of claim 8 , wherein the threshold event is the first battery unit dropping below a threshold voltage for a first battery unit.

18. The system of claim 8 , wherein the threshold event is a depth of discharge of the first battery unit dropping below a threshold depth of discharge level.

19. The system of claim 18 , wherein the control system is configured to electrically de-couple, through a first switch, the first battery unit from the load, when the first battery unit drops below the threshold depth of discharge level.

20. The system of claim 19 , wherein the control system is also configured to electrically de-couple, through a second switch, the second battery unit from the load, when the second battery unit drops below a threshold depth of discharge level.

21. The system of claim 18 , wherein the threshold depth of discharge level is about 10% of a full state of charge.

22. The system of claim 18 , wherein the threshold depth of discharge level is about 20% of a full state of charge.

23. The system of claim 1 , wherein a first battery efficiency is at least about 10% higher than a second battery efficiency.

24. The system of claim 1 , wherein a first battery efficiency is at least about 20% higher than a second battery efficiency.

25. The system of claim 1 , wherein the first battery unit incorporates only first batteries.

26. The system of claim 1 , wherein the second battery unit incorporates only second batteries.

27. The system of claim 1 , wherein the first battery unit incorporates only first batteries, and wherein the second battery unit incorporates only second batteries.

28. The system of claim 27 , wherein the first battery unit consists of lithium ion batteries and the second battery unit consists of rechargeable metal-air batteries.

29. The system of claim 27 , wherein the first battery unit consists of lithium ion batteries and the second battery unit consists of rechargeable zinc-air batteries.

30. The system of claim 1 , wherein the first battery unit comprises a lithium ion battery and the second battery unit comprises a zinc-air battery.

31. The system of claim 1 , wherein the second battery unit incorporates a third battery, wherein the third battery is a different type of battery than the second battery.

32. The system of claim 31 , wherein the third battery is a hybrid metal-air battery comprising a reversible metal in one of an electrode.

33. The system of claim 1 , further comprising a supplemental power source that is coupled to the load.

Assignees

• Form Energy Inc

Inventors

• Krishnan Ramkumar
• Fink Shawn

Classifications

• H02J2105/12

  supplying households or buildings · CPC title

• H02J2101/28

  Wind energy · CPC title

• H02J2101/24

  Photovoltaics · CPC title

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/855

  with circuits adapted for supplying loads from the battery · CPC title