Model predictive battery power limit estimation systems and methods

1 . A battery system comprising:

a battery comprising terminals for electrically coupling to an electrical system;

one or more sensors electrically coupled to the battery and configured to determine sensor data indicative of measured operational parameters of the battery, the measured operational parameters comprising a measured terminal voltage; and

a battery control system communicatively coupled to the one or more sensors, the battery control system being programmed to:

determine a predicted internal resistance of the battery expected to occur during a prediction horizon;

determine a real-time internal resistance of the battery during the prediction horizon;

when the measured terminal voltage of the battery is less than a lower voltage threshold, control charging of the battery using a charging power limit determined based on the predicted internal resistance; and

when the measured terminal voltage of the battery is greater than the lower voltage threshold, control charging of the battery using the charging power limit determined based on the real-time internal resistance.

2 . The battery system of claim 1 , wherein the battery control system is programmed to:

determine the charging power limit used to control supply of electrical power to the battery based on the predicted internal resistance when the measured terminal voltage of the battery is less than a lower voltage threshold; and

determine the charging power limit based on the real-time internal resistance when the measured terminal voltage of the battery is greater than the lower voltage threshold.

3 . The battery system of claim 1 , wherein the determining the predicted internal resistance occurs when the measured terminal voltage of the battery is less than a lower voltage threshold and wherein the determining the real-time internal resistance occurs when the measured terminal voltage of the battery is greater than the lower voltage threshold.

4 . The battery system of claim 1 , wherein the predicted internal resistance is determined based on operational conditions projected over a prediction horizon.

5 . The battery system of claim 1 , wherein the real-time internal resistance is determined based on the measured terminal voltage of the battery and a battery model that describes a relationship between measured battery parameters and internal resistance of the battery.

6 . The battery system of claim 1 , wherein:

the one or more sensors are configured to determine sensor data indicative of a measured current flow through the battery; and

to determine the real-time internal resistance, the battery control system is further programmed to:

determine an open-circuit voltage of the battery; and

determine the real-time internal resistance of the battery based on difference between the measured terminal voltage of the battery and the open-circuit voltage of the battery divided by the measured current flow through the battery.

7 . The battery system of claim 6 , wherein, to determine the open-circuit voltage of the battery, the battery control system is further programmed to:

determine an initial state-of-charge of the battery;

determine a current state-of-charge of the battery based on current through the battery between the initial state-of-charge and the current state-of-charge; and

determine the open-circuit voltage of the battery based on the current state-of-charge of the battery.

8 . The battery system of claim 1 , wherein:

the one or more sensors are configured to determine sensor data indicative of measured current through the battery; and

the battery control system is further programmed to:

determine a predicted current flow through the battery expected to occur during the prediction horizon by projecting the measured current over the prediction horizon;

determine a predicted terminal voltage of the battery expected to occur during the prediction horizon by projecting the measured terminal voltage over the prediction horizon; and

determine the predicted internal resistance expected to occur during the prediction horizon based on the predicted current flow and the predicted terminal voltage.

9 . The battery system of claim 5 , comprising a temperature sensor configured to determine sensor data indicative of a temperature of the battery, wherein the battery control system is programmed to adjust model parameters of the battery model based on the temperature of the battery.

10 . An electrical system comprising:

a battery system comprising:

a battery comprising terminals for electrically coupling to an electrical system;

one or more sensors electrically coupled to the battery and configured to determine sensor data indicative of measured operational parameters of the battery, the measured operational parameters comprising a measured terminal voltage; and

a battery control system communicatively coupled to the one or more sensors, the battery control system being programmed to:

determine a predicted internal resistance of the battery expected to occur during a prediction horizon, and a real-time internal resistance of the battery during the prediction horizon; and

when the measured terminal voltage of the battery is:

less than a lower voltage threshold, determine a charging power limit used to control supply of electrical power to the battery based on the predicted internal resistance; and

greater than the lower voltage threshold, determine the charging power limit based on the real-time internal resistance;

an electrical power source and an electrical load electrically coupled to the terminals of the battery; and

an electrical control system communicatively coupled to the battery control system and the electrical power source, wherein the electrical control system is programmed to:

receive an indication of the charging power limit from the battery control system; and

instruct the electrical power source to supply electrical power to the battery in accordance with the charging power limit.

11 . The battery system of claim 10 , wherein the battery control system is programmed to instruct the battery system to electrically disconnect the battery from the electrical load when the measured terminal voltage of the battery exceeds an upper voltage threshold greater than the lower voltage threshold to facilitate improving lifespan of the battery.

12 . The battery system of claim 10 , wherein the measured operational parameters of the battery include a measured current flow through the battery.

13 . The battery system of claim 12 , wherein the battery control system is programmed to determine the real-time internal resistance of the battery based on a difference between the measured terminal voltage of the battery and an open-circuit voltage of the battery divided by the measured current flow through the battery.

14 . The battery system of claim 13 , wherein the battery control system is further programmed to for the determination of the open-circuit voltage to:

instruct the battery system to electrically disconnect the battery from one or more electrical devices of the electrical system; and

determine the open-circuit voltage of the battery based on the measured terminal voltage after the battery is maintained electrically disconnected from the one or more electrical devices a duration greater than a rest duration threshold.

15 . A method for controlling charging of a battery in an electrical system, comprising:

determining, using a control system, a measured terminal voltage of the battery based on sensor data received from a first sensor;

determining, using the control system, a predicted terminal voltage of the battery expected to occur during a prediction horizon by projecting the measured terminal voltage over the prediction horizon;

determining using the control system:

a predicted internal resistance of the battery expected to occur during the prediction horizon based on the predicted terminal voltage; and

a real-time internal resistance of the battery based on the measured terminal voltage of the battery;

determining, using the control system, a charging power limit based on:

the predicted internal resistance of the battery expected to occur during the prediction horizon, when the measured terminal voltage of the battery is less than a lower voltage threshold; and

the real-time internal resistance of the battery, when the measured terminal voltage of the battery is greater than the lower voltage threshold; and

instructing, using the control system, an electrical power source to adjust charging power supplied to the battery based on the charging power limit.

16 . The method of claim 15 , comprising:

determining, using the control system, measured current flow through the battery based on sensor data received from a second sensor; and

when the measured terminal voltage of the battery is not greater than the lower voltage threshold:

determining, using the control system, a predicted current flow through the battery expected to occur during the prediction horizon by projecting the measured current flow over the prediction horizon; and

determining, using the control system, the predicted internal resistance of the battery expected to occur during the prediction horizon based on the predicted current flow through the battery.

17 . The method of claim 16 , comprising:

determining, using the control system, open-circuit voltage of the battery; and

determining, using the control system, the real-time internal resistance of the battery based on:

difference between the measured terminal voltage of the battery and the open-circuit voltage of the battery divided by the measured current flow through the battery when the measured terminal voltage of the battery is greater than the lower voltage threshold; and

a battery model that relates measured operational parameters to model parameters comprising internal resistance of the battery.

18 . The method of claim 17 , comprising:

determining, using the control system, state-of-charge of the battery based on the measured current flow through the battery; and

determining, using the control system, the open-circuit voltage of the battery based on the state-of-charge of the battery.

19 . The method of claim 15 , comprising instructing, using the control system, a switching device electrically coupled between the battery and the electrical power source to switch to an open position when the measured terminal voltage of the battery exceeds an upper voltage threshold greater than the lower voltage threshold.

20 . The method of claim 15 , wherein the determining the measure terminal voltage of the battery and the determining the predicted terminal voltage of the battery occurs when the measured terminal voltage of the battery is less than a lower voltage threshold, determining, and wherein the determining the real-time internal resistance of the battery occurs when the measured terminal voltage of the battery is greater than the lower voltage threshold.