EARLY ALERT OF BATTERY THERMAL STATE BASED ON VOLTAGE

• US 20170054311A1
• Filed: 08/17/2015
• Published: 02/23/2017
• Est. Priority Date: 08/17/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: MASIAS, Alvaro, SNYDER, KENT, MILLER, THEODORE JAMES
• Granted Patent: US 10,164,450 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 2250/10 by alarm
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/62 in response to charging parameters, e.g. current, voltage or electrical charge
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• 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 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles

Abstract

A battery management controller includes input channels to receive a voltage signal from a battery and output channels to provide diagnostic signals to an operator. The controller is programmed to output a diagnostic signal predictive of a thermal condition in response to the voltage decreasing at a rate greater than a predetermined rate that signals that the voltage is decreasing toward a local minimum that precedes an increase in the voltage indicative of a battery temperature increase rate becoming greater than a threshold. The diagnostic signal may be used to alert the operator of the condition. The controller may be further programmed to issue commands to mitigate the thermal condition based on the diagnostic signal.

Claims

1. A vehicle comprising:

a traction battery; and

at least one controller programmed to, monitor a voltage of the traction battery during charging and, in response to the voltage decreasing at a rate greater than a predetermined rate signaling that the voltage is decreasing toward a local minimum that precedes an increase in the voltage indicative of a traction battery temperature increase rate becoming greater than a threshold, output a diagnostic signal.

2. The vehicle of claim 1 wherein the at least one controller is further programmed to, in response to the diagnostic signal, open a contactor to disconnect the traction battery from a charge source.

3. The vehicle of claim 1 wherein the at least one controller is further programmed to, in response to the diagnostic signal, command a charge source to cease charging the traction battery.

4. The vehicle of claim 1 wherein the traction battery is charged at a constant current.

5. The vehicle of claim 1 wherein the voltage is measured across terminals of the traction battery.

6. The vehicle of claim 1 wherein the traction battery includes a plurality of cells arranged in a plurality of modules, and the voltage is measured across one of the modules.

7. The vehicle of claim 1 wherein the traction battery includes a plurality of cells and the voltage is measured across one of the cells.

8. The vehicle of claim 1 further comprising an alarm, wherein the at least one controller is further programmed to, in response to the diagnostic signal, activate the alarm to provide an alert.

9. A battery controller comprising:

input channels configured to receive a voltage signal from a battery;

output channels configured to provide diagnostic signals; and

control logic configured to, in response to the voltage signal decreasing during charging at a rate greater than a predetermined rate signaling that voltage is decreasing toward a local minimum that precedes an increase in voltage indicative of a battery temperature increase rate becoming greater than a threshold, generate a diagnostic signal.

10. The battery controller of claim 9 further comprising a communication channel for communicating with a charge source, wherein the control logic is further configured to command the charge source to cease charging in response to the diagnostic signal.

11. The battery controller of claim 9 wherein at least one of the output channels is further configured to interface with a contactor and the control logic is further configured to command the contactor to disconnect the battery from a charge source in response to the diagnostic signal.

12. The battery controller of claim 9 wherein at least one of the output channels is further configured to interface with a load coupled to the battery and the control logic is further configured to command the load to draw current from a charge source in response to the diagnostic signal.

13. The battery controller of claim 9 wherein the voltage signal is based on an overall pack voltage.

14. The battery controller of claim 9 wherein the voltage signal is based on a module voltage that includes a subset of cells that comprise the battery.

15. The battery controller of claim 9 wherein the voltage signal is based on a battery cell voltage.

16. The battery controller of claim 9 wherein at least one of the output channels is further configured to interface with an alarm and the control logic is further configured to command activation of the alarm in response to the diagnostic signal.

17. A method of monitoring a battery comprising:

monitoring, by at least one controller, a voltage of the battery during charging; and

outputting, by the at least one controller, a diagnostic signal in response to the voltage decreasing at a rate greater than a predetermined rate signaling that the voltage is decreasing toward a local minimum that precedes an increase in the voltage indicative of a battery temperature increase rate becoming greater than a threshold.

18. The method of claim 17 further comprising opening, by the at least one controller, a contactor to disconnect the battery from a charge source in response to the diagnostic signal.

19. The method of claim 17 further comprising commanding, by the at least one controller, a charge source to cease providing current for charging in response to the diagnostic signal.

20. The method of claim 17 further comprising commanding, by the at least one controller, a load coupled to the battery to draw current from a charge source in response to the diagnostic signal.