Voltage based zero configuration battery management

Patent metadata

Field	Value
Publication number	US-11169213-B2
Application number	US-201815966284-A
Country	US
Kind code	B2
Filing date	Apr 30, 2018
Priority date	May 5, 2017
Publication date	Nov 9, 2021
Grant date	Nov 9, 2021

Abstract

Controllers and methods to manage a battery, in which a controller estimates scale factor and a steady state current rate according to multiple battery voltage values and a steady state model during steady state operation, and estimates the current rate according to a battery voltage value, the scale factor, and a dynamic model of the battery during dynamic operation, and the controller estimates a remaining capacity of the battery according to the current rate, without requiring controller reconfiguration for different batteries.

First claim

The following is claimed:

1. A controller for use in a battery management system having a battery, the controller comprising:
a memory storing a set of instructions; and
a processor, upon retrieving and implementing the instructions stored in the memory, configured to:
estimate a current rate, when the battery is in a steady state mode, according to: a first battery voltage sample that represents a battery voltage of the battery at a first sample time, a second battery voltage sample that represents the battery voltage at a second sample time, a temperature sample that represents a temperature of the battery at the first sample time, and a steady state model of the battery;
estimate a scale factor, when the battery is in the steady state mode, the scale factor representing a deviation in a normalized resistance of the battery according to the first battery voltage sample;
estimate the current rate, when the battery is in a dynamic mode, according to: a voltage value, the temperature sample, the scale factor, and a dynamic model of the battery; and
estimate a remaining capacity of the battery according to the current rate.

2. The controller of claim 1 :
wherein the memory stores a lookup table that represents an open circuit voltage and a resistance of a particular battery type; and
wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, when the battery is operating in the steady state mode, to:
determine an open circuit voltage value and a resistance value of the battery by linear interpolation of the lookup table according to: the temperature sample, and a depth of discharge of the battery;
estimate the current rate according to: voltage values computed by linear regression, the open circuit voltage value, and the resistance value of the battery; and
estimate the scale factor according to: one of the voltage values computed by linear regression, the open circuit voltage value, and the resistance value of the battery.

3. The controller of claim 1 ,
wherein the memory stores dynamic model parameters that represent a particular battery type; and
wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, when the battery is operating in the dynamic mode, to:
estimate the current rate according to: an instantaneous battery voltage sample, the temperature sample, the scale factor, and the dynamic model parameters.

4. The controller of claim 1 , wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, to estimate the remaining capacity of the battery according to the current rate using an end of discharge convergence algorithm.

5. The controller of claim 1 , wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, to estimate the remaining capacity of the battery as a present depth of discharge (DOD) value for the battery according to a previous DOD value and the current rate.

6. The controller of claim 1 , wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, to:
estimate the current rate, when the battery is in the steady state mode, according to: battery voltage values that are obtained by fitting successive voltage samples to a straight line using piecewise linear regression, the temperature sample, and the steady state model; and
estimate the current rate, when the battery is in the dynamic mode, according to: an instantaneous battery voltage, the temperature sample, the scale factor, and a dynamic model of the battery.

7. The controller of claim 1 , wherein the processor is further configured to, upon retrieving and implementing the instructions stored in the memory, estimate the remaining capacity of the battery according to the current rate using an end of discharge convergence algorithm.

8. The controller of claim 7 , wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, to: estimate a maximum voltage value according to a charging voltage during charging of the battery, and correlate a maximum remaining capacity value to the maximum voltage value.

9. The controller of claim 1 , wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, to:
determine whether the battery is operating in the steady state mode or the dynamic mode according to changes in the current rate obtained by tracking an average change in voltage.

10. The controller of claim 9 , wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, to:
determine that the battery is operating in the dynamic mode in response to detecting a change in the current rate; and
determine that the battery is operating in the steady state mode in response to detecting no change in the current rate for a non-zero time.

11. The controller of claim 9 , wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, to estimate the remaining capacity of the battery according to the current rate using an end of discharge convergence algorithm.

12. The controller of claim 9 :
wherein the memory stores a lookup table that represents an open circuit voltage and a resistance of a particular battery type; and
wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, when the battery is operating in the steady state mode, to:
determine an open circuit voltage value and a resistance value of the battery by linear interpolation of the lookup table according to: the temperature sample, and a depth of discharge of the battery;
estimate the current rate according to: voltage values computed by linear regression, the open circuit voltage value, and the resistance value of the battery; and
estimate the scale factor according to: one of the voltage values computed by linear regression, the open circuit voltage value, and the resistance value of the battery.

13. The controller of claim 12 ,
wherein the memory stores dynamic model parameters that represent the particular battery type; and
wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, when the battery is operating in the dynamic mode, to:
estimate the current rate according to: an instantaneous battery voltage sample, the temperature sample, the scale factor, and the dynamic model parameters.

14. The controller of claim 13 , wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, to estimate the remaining capacity of the battery according to the current rate using an end of discharge convergence algorithm.

15. The controller of claim 13 , wherein the processor is further configured, upon retrieving and implementing the instructions stored in the memory, to estimate a maximum voltage value according to a charging voltage during charging of the battery, and to correlate a maximum remaining capacity value to the maximum voltage value.

16. A method of managing a battery, the method comprising:
when a battery is operating in a steady state mode, estimating, by a controller, a current rate according to a first battery voltage sample that represents a battery voltage of the battery at a first sample time, a second battery voltage sample that represents the battery voltage at a

Assignees

• Texas Instruments Inc

Inventors

• Karippumannil Prasad Githin
• Barsukov Yevgen Pavlovich
• Blackwell Dale Allen

Classifications

• H02J7/865

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

• G01R31/389

  Measuring internal impedance, internal conductance or related variables · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/4257

  Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries · CPC title

• G01R31/374

  with means for correcting the measurement for temperature or ageing · CPC title