BATTERY VOLTAGE PROFILE MONITORING DURING GENERATOR START

• US 20160003919A1
• Filed: 12/19/2012
• Published: 01/07/2016
• Est. Priority Date: 12/19/2012
• Status: Active Grant

• Current Assignee: Schneider Electric USA, Inc. (Schneider Electric SE)
• Original Assignee: Schneider Electric USA, Inc. (Schneider Electric SE)
• Inventors: Hirschbold, Markus F., Van Gorp, John C., Harding, Stewart J., Demasson, Donald Theodore
• Granted Patent: US 9,784,798 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60W 2510/248 Age of storage means
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 2041/228 Warning displays
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• CPC Class Codes: F02N 11/10 Safety devices F02N11/08 takes precedence
• CPC Class Codes: F02N 2200/063 Battery voltage
• CPC Class Codes: F02N 2250/02 Battery voltage drop at start, e.g. drops causing ECU reset
• CPC Class Codes: G01R 22/061 Details of electronic electricity meters
• 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 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10

Abstract

Disclosed herein are embodiments of systems and methods for determining the state of health of a generator battery set and its ability to supply generator starter motor with start-up energy by capturing a profile of voltage across terminals of the battery during a supply of electrical energy from the battery to the starter and comparing the captured voltage profile to a reference voltage profile to determine if a difference between the captured voltage profile and reference voltage profile exceeds an acceptable amount.

Claims

1. A method of determining a state of health of a generator battery and an ability of the battery to supply a generator starter motor with start-up energy, the method comprising:

building a reference voltage profile for generator starts;

capturing a battery voltage profile during a generator start operation;

comparing the captured battery voltage profile to the reference voltage profile; and

determining if one or more parameters of the captured battery profile differs from one or more parameters of the reference voltage profile by more than a predetermined amount.

2. The method of claim 1, further comprising issuing a warning if one or more parameters of the captured battery profile differs from one or more parameters of the reference voltage profile by more than a predetermined amount.

3. The method of claim 2, wherein building the reference voltage profile for generator starts comprises defining one or more regions of the reference voltage profile, each of the one or more regions having a duration and a magnitude of voltage change, and wherein capturing the battery voltage profile comprises defining one or more regions in the captured battery voltage profile corresponding to the one or more regions defined in the reference voltage profile.

4. The method of claim 3, wherein comparing the captured battery voltage profile to the reference voltage profile comprises comparing one of a duration and a voltage change magnitude of at least one region of the captured battery voltage profile to a corresponding region of the reference voltage profile.

5. The method of claim 3, further comprising building a mathematical model describing the reference voltage profile in the one or more regions and issuing the warning responsive to the captured battery voltage profile differing from the mathematical model in corresponding one or more of the one or more regions by more than a predetermined amount.

6. The method of claim 5, wherein building the reference voltage profile for generator starts comprises defining an engagement region, a cranking region, and a generator starting region.

7. The method of claim 6, wherein building the mathematical model comprises representing a drop in battery voltage in the engagement region with a straight line equation.

8. The method of claim 6, wherein building the mathematical model comprises defining one of a second order and or third order polynomial equation representing the reference voltage profile in one of the cranking region and the generator start region.

9. The method of claim 5, wherein the method further comprises:

defining one or more mathematical equations describing the voltage profile in the one or more regions;

defining statistical process control limits about the one or more mathematical equations; and

issuing the warning responsive to data points in the captured battery profile violating a statistical process control rule relative to the statistical process control limits.

10. The method of claim 2, wherein issuing the warning comprises issuing the warning responsive to a cumulative sum of values of differences between a plurality of measurements of the voltage of the captured battery profile and the voltage of the reference voltage profile at corresponding points in time exceeding a predefined limit.

11. The method of claim 3, comprising issuing the warning responsive to a standard deviation of a plurality of measurements of the voltage in one or more of the regions exceeding a standard deviation of voltage in the reference voltage profile in corresponding one or more regions by more than a predefined amount.

12. The method of claim 3, wherein issuing the warning comprises issuing the warning responsive to one or more parameters of at least two of the regions of the captured voltage profile differing from one or more parameters of corresponding regions of the reference voltage profile by more than predetermined amounts.

13. The method of claim 3, wherein issuing the warning comprises issuing the warning responsive to one or more parameters of a region of the captured voltage profile differing from one or more parameters of a corresponding region of the reference voltage profile by more than predetermined amount for more than a predetermined amount of time.

14. The method of claim 2, further comprising generating a plurality of reference voltage profiles corresponding to different levels of an environmental factor and comparing the captured voltage profile to a reference voltage profile selected from the plurality of voltage reference profiles responsive to a level of the environmental factor.

15. The method of claim 2, further comprising monitoring a steady-state voltage profile of the battery during a time other than during the generator start operation and issuing a warning responsive to the monitored steady-state voltage profile differing from a reference steady-state voltage profile by greater than a predefined amount.

16. A system determining a state of health of a generator battery and an ability of the battery to supply a generator starter motor with start-up energy, the system comprising:

a battery electrically coupled to a starter motor for the generator; and

a monitoring system including an electrical meter electrically coupled to the battery and configured to capture a profile of voltage across terminals of the battery during a supply of electrical energy from the battery to the starter, the monitoring system further configured to compare the captured voltage profile to a reference voltage profile and determine if a difference between the captured voltage profile and reference voltage profile exceeds an acceptable amount.

17. The system of claim 16, further including an output configured to issue a warning responsive to the difference between the captured voltage profile and the reference voltage profile exceeding the acceptable amount.

18. The system of claim 16, wherein the monitoring system is configured to generate the reference voltage profile from an aggregation of a plurality of previously captured battery voltage profiles.

19. The system of claim 18, wherein the monitoring system is configured to generate the reference voltage profile from an aggregation of a plurality of previously captured battery voltage profiles captured over a moving window of time during which a predefined number of generator start operations were performed.

20. The system of claim 16, wherein the monitoring system is configured to define one or more regions of the reference profile having a duration and a magnitude of voltage change, to define one or more regions of the captured voltage profile having a duration and a magnitude of voltage change, and to compare one of the duration and the voltage change magnitude of at least one region of the captured battery voltage profile to that of a corresponding region of the reference voltage profile to determine if a difference between the captured voltage profile and reference voltage profile exceeds the acceptable amount.