Redox flow battery with floating power module under imbalanced charge conditions

Patent metadata

Field	Value
Publication number	US-12347908-B2
Application number	US-202217680594-A
Country	US
Kind code	B2
Filing date	Feb 25, 2022
Priority date	Feb 25, 2022
Publication date	Jul 1, 2025
Grant date	Jul 1, 2025

Abstract

The present disclosure is directed, in certain embodiments, to a flow cell battery system. A battery management system detects that a first power module and a second power module located adjacent to the first power module are operating at different states of charge. After determining that the second power module is at the lower state of charge than the first power module, a negative-side switch associated with the second power module is adjusted to an open position, thereby preventing flow of electrical current from a negative terminal of the second power module to electrical ground.

First claim

What is claimed is:

1. A flow cell battery system, comprising:
an AC/DC inverter;
a first power module comprising:
a first positive terminal electronically coupled to a positive bus connected to a positive side of the AC/DC inverter;
a first negative terminal electronically coupled to a first negative-side switch, the first negative-side switch operable to:
when closed, allow flow of electrical current from the first negative terminal of the first power module to electrical ground; and
when open, prevent flow of electrical current from the first negative terminal of the first power module to electrical ground;

a second power module located adjacent to the first power module, the second power module comprising:
a second positive terminal electronically coupled to the positive bus connected to the positive side of the AC/DC inverter;
a second negative terminal electronically coupled to a second negative-side switch, the second negative-side switch operable to:
when closed, allow flow of electrical current from the second negative terminal of the second power module to electrical ground; and
when open, prevent flow of electrical current from the second negative terminal of the second power module to electrical ground; and

a battery management system comprising a hardware processor configured to:
detect that the first and second power modules are operating at a different state of charge;
determine that the second power module is at a lower state of charge than the first power module,
after determining that the second power module is at the lower state of charge than the first power module, adjust the second negative-side switch to the open position.

2. The battery system of claim 1 , wherein, after determining that the second power module is at the lower state of charge than the first power module, the first negative-side switch is in the closed position.

3. The battery system of claim 1 , wherein adjusting the second negative-side switch to the open position causes the second power module to electronically float at a predetermined range of voltages relative to an electronic voltage of the first power module.

4. The battery system of claim 1 , wherein the hardware processor is further configured to detect that the first and second power modules are operating at a different state of charge by determining that the first power module is in a charging state and the second power module is in a shutdown state.

5. The battery system of claim 1 , further comprising one or more pumps and corresponding liquid manifolds operable to control a flow of electrolyte solution through cells of the first and second power modules.

6. The battery system of claim 5 , wherein the one or more pumps and corresponding liquid manifolds comprise:
a first pump and first liquid manifolds configured to provide the flow of electrolyte solution to the first power module; and
a second pump and second liquid manifolds configured to provide the flow of electrolyte solution to the second power module.

7. The battery system of claim 1 , wherein:
the first positive terminal of the first power module is electronically coupled to a first positive-side switch, the first positive-side switch operable to:
when closed, allow flow of electrical current from the first positive terminal of the first power module to a positive side of the AC/DC inverter; and
when open, prevent flow of electrical current from the first positive terminal of the first power module to the positive side of the AC/DC inverter; and

the second positive terminal of the second power module is electronically coupled to a second positive-side switch, the second positive-side switch operable to:
when closed, allow flow of electrical current from the second positive terminal of the second power module to a positive side of the AC/DC inverter; and
when open, prevent flow of electrical current from the second positive terminal of the second power module to the positive side of the AC/DC inverter;

wherein when the first power module is in a charging state, the first positive-side switch is closed and when the second power module is in a shutdown state, the second positive-side switch is open.

8. The battery system of claim 1 , further comprising an electrolyzer configured to electrolyze an electrolyte solution provided to the second power module.

9. A battery management system for a flow cell battery, the battery management system comprising:
an input/output interface communicatively coupled to:
a first negative-side switch associated with a first power module of the flow cell battery, wherein the first negative-side switch is operable to:
when closed, allow flow of electrical current from the first negative terminal of the first power module to electrical ground; and
when open, prevent flow of electrical current from the first negative terminal of the first power module to electrical ground; and

a second negative-side switch associated with a second power module of the flow cell battery, wherein the second power module is located adjacent to the first power module, wherein the second negative-side switch is operable to:
when closed, allow flow of electrical current from the second negative terminal of the second power module to electrical ground; and
when open, prevent flow of electrical current from the second negative terminal of the second power module to electrical ground; and

a hardware processor communicatively coupled to the input/output interface and configured to:
detect that the first and second power modules are operating at a different state of charge;
determine that the second power module is at a lower state of charge than the first power module,
after determining that the second power module is at the lower state of charge than the first power module, adjust the second negative-side switch to the open position.

10. The battery management system of claim 9 , wherein, after determining that the second power module is at the lower state of charge than the first power module, the first negative-side switch is in the closed position.

11. The battery management system of claim 9 , wherein adjusting the second negative-side switch to the open position causes the second power module to electronically float at a predetermined range of voltages relative to an electronic voltage of the first power module.

12. The battery management system of claim 9 , wherein the hardware processor is further configured to detect that the first and second power modules are operating at a different state of charge by determining that the first power module is in a charging state and the second power module is in a shutdown state.

13. The battery management system of claim 12 , wherein the input/output interface is further communicatively coupled to one or more pumps operable to control a flow of electrolyte solution through cells of the first and second power modules.

14. The battery management system of claim 9 , wherein the input/output interface is further communicatively coupled to:
a first positive-side switch associated with the first power module and operable to:
when closed, allow flow of electrical current from the first positive terminal of the first power module to a positive side of the AC/DC inverter; and
when open, prevent flow of electrical current from the first positive terminal of the first power module to the positive side of the AC/DC inverter; and

a second positive-side switch associated with the second power module and operable to:
when closed, allow flow of electrical current from the second positive terminal of the second power module to the positive

Assignees

• Lockheed Martin Energy Llc

Inventors

• Hamel Jonathan
• Holmquest Kyra Coffey
• Beverage Kevin Hartley

Classifications

• H02J7/865

  Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence) · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/02

  for charging batteries from AC mains by converters · CPC title

• H01M8/04574

  Current · CPC title

• H01M8/0289

  Means for holding the electrolyte (solid polymer electrolytes H01M8/1018) · CPC title