METHODS AND SYSTEMS FOR WARNING USERS OF A DEGRADED BACKUP CAPACITY IN BATTERY PLANTS

• US 20140266226A1
• Filed: 03/14/2013
• Published: 09/18/2014
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Vertiv Corporation (Vertiv Holdings Co.)
• Original Assignee: Emerson Network Power Energy Systems North America Incorporated (Emerson Electric Company)
• Inventors: Essi, David Ferris III
• Granted Patent: US 9,347,999 B2
• Time in Patent Office: Days
• US Class Current: 324/427
• CPC Class Codes: G01R 31/3646 for indicating electrical conditions or variables, e.g. visual or audible indicators
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health

Abstract

A method of warning a user when a reserve time of a battery plant in a system is substantially degraded is disclosed. The method includes determining a baseline capacity for the battery plant by estimating the reserve time of the battery plant while the battery plant is installed in the system, subsequently determining a present capacity of the battery plant by estimating the reserve time of the battery plant while the battery plant is installed in the system, comparing the present capacity with the baseline capacity, and generating a warning when the baseline capacity exceeds the present capacity by more than a defined amount. Example embodiments of systems and control circuits configured to perform the methods are also disclosed herein.

Claims

1. A method of warning a user when a backup capacity of a battery plant in a system is substantially degraded, the method comprising:

determining a baseline capacity for the battery plant by estimating a reserve time of the battery plant while the battery plant is installed in the system;

determining a present capacity of the battery plant by estimating the reserve time of the battery plant while the battery plant is installed in the system;

comparing the present capacity with the baseline capacity; and

generating a warning when the baseline capacity exceeds the present capacity by more than a defined amount.

2. The method of claim 1 wherein determining the baseline capacity includes estimating the reserve time of the battery plant a plurality of times during a first period to generate a plurality of reserve times, one of the plurality of reserve times being a largest reserve time, and setting the baseline capacity to equal the largest reserve time.

3. The method of claim 2 wherein the first period is about 183 days.

4. The method of claim 2 wherein determining the present capacity includes determining the present capacity after the first period.

5. The method of claim 2 wherein generating includes generating the warning when the present capacity is less than N times the baseline capacity, where 0<

N<

1.

6. The method of claim 5 wherein N is 0.8.

7. The method of claim 1 wherein the reserve time is a time '"'"'til empty (TTE) of the battery plant.

8. The method of claim 1 wherein the battery plant includes one or more batteries.

9. The method of claim 1 wherein estimating includes estimating the reserve time of the battery plant while the battery plant is discharging.

10. A non-transitory computer readable medium storing computer-executable instructions for warning a user when a backup capacity of a battery plant in a system is substantially degraded, the instructions configured to determine a baseline capacity for the battery plant by estimating a reserve time of the battery plant while the battery plant is installed in the system, determine a present capacity of the battery plant by estimating the reserve time of the battery plant while the battery plant is installed in the system, compare the present capacity with the baseline capacity, and generate a warning when the baseline capacity exceeds the present capacity by more than a defined amount.

11. A system for warning a user when a backup capacity of a battery plant is substantially degraded, the system comprising a power plant including a main power supply for providing power to a load and a battery plant coupled to the main power supply, the battery plant including one or more batteries for providing power to the load when the main power supply is inoperable, and a control circuit coupled to the power plant and configured to determine a baseline capacity for the battery plant by estimating a reserve time of the battery plant while the battery plant is installed in the system, determine a present capacity of the battery plant by estimating the reserve time of the battery plant while the battery plant is installed in the system, compare the present capacity with the baseline capacity, and generate a warning when the baseline capacity exceeds the present capacity by more than a defined amount.

12. The system of claim 11 further comprising a sensor coupled to the power plant, the sensor configured to sense a parameter of the system to estimate the reserve time.

13. The system of claim 12 wherein the sensed parameter is a sensed battery plant voltage or a sensed output current.

14. The system of claim 13 further comprising a sensor configured to sense an output current of the system, wherein the control circuit is configured to determine the baseline capacity and the present capacity from the estimated reserve time and the sensed output current.

15. The system of claim 14 wherein the main power supply includes a rectifier.

16. The system of claim 11 wherein the control circuit is positioned in a first city and the power plant is positioned in a second city different than the first city.

17. The system of claim 11 wherein the control circuit is positioned in a first building and the power plant is positioned in a second building different than the first building.

18. The system of claim 11 wherein the reserve time is a time '"'"'til empty (TTE) of the battery plant.