State-of-charge estimator for lithium-ion battery using hysteresis model
AssigneeGM Global Technology Operations LLC
InventorsJun-Mo Kang, Hanho Yun
Life of this patent
Estimating the term…
Abstract
An electric vehicle (EV), and systems and methods are introduced in aspects of the disclosure that use a battery management system (BMS) for one or more Lithium ion (Li+) battery cells. The BMS includes an apparatus coupled with outer terminals of the one or more Li+ battery cells and configured to estimate an open circuit voltage (VOC) across the Li+ battery cells. The apparatus further includes a memory, at least one processor coupled with the memory. The at least one processor is configured, when executing code stored in the memory, to produce a state of charge (SOC) observer, the SOC observer including a hysteresis model to account for hysteresis in the one or more Li+ battery cells.
Claims20
A battery management system (BMS) for one or more Lithium ion (Li+) battery cells, comprising:
- an apparatus coupled with outer terminals of the one or more Li+ battery cells and configured to estimate an open circuit voltage (VOC) across the Li+ battery cells, the apparatus further comprising:
- a memory;
- and
- at least one processor coupled with the memory and configured, when executing code stored in the memory, to produce a state of charge (SOC) observer, the SOC observer including a hysteresis model to account for differential hysteresis in the one or more Li+ battery cells;
- wherein the at least one processor is arranged to effect charging and discharging of the one or more Li+ battery cells to execute the hysteresis model;
- wherein the hysteresis model dynamically models direction-dependent VOC behavior of the one or more Li+ battery cells based upon a direction of current flow and a state of charge;
- and
- wherein the SOC observer determines the SOC for the one or more Li+ battery cells based upon the VOC across the one or more Li+ battery cells.
An electric vehicle (EV), comprising:
- a body, the body coupled to a dashboard, the body housing an internal vehicle cabin, the internal vehicle cabin having a plurality of controls and dials including an indicator identifying an amount of charge or a time period remaining for the EV to continue to run, the identified amount of charge or time period based on a state of charge (SOC) of lithium ion (Li+) battery cells powering the EV;
- a powertrain system coupled with the body and coupled to at least four wheels;
- and
- a battery management system (BMS) for one or more of the Li+ battery cells, the BMS comprising:
- an apparatus coupled with outer terminals of the one or more of the Li+ battery cells and configured to estimate a state of charge (SOC) of the Li+ battery cells, the apparatus further comprising:
- a memory;
- and
- at least one processor coupled with the memory and configured, when executing code stored in the memory, to produce a state of charge (SOC) observer, the SOC observer including a hysteresis model to account for differential hysteresis in the one or more Li+ battery cells;
- wherein the at least one processor is arranged to effect charging and discharging of the one or more Li+ battery cells to execute the hysteresis model;
- wherein the hysteresis model dynamically models direction-dependent VOC behavior of the one or more Li+ battery cells based upon a direction of current flow and a state of charge;
- and
- wherein the SOC observer determines the SOC for the one or more Li+ battery cells based upon the VOC across the one or more Li+ battery cells.
A method for determining the state of charge (SOC) of an electric vehicle (EV) powered by lithium ion (Li+) battery cells exhibiting hysteresis, comprising:
- coupling a battery management system (BMS) with outer terminals of the Li+ battery cells;
- executing code on at least one processor to determine an open circuit voltage (VOC);
- coupling the BMS with outer terminals of the Li+ battery cells;
- and
- executing code by at least one processor within the BMS to produce a state of charge (SOC) observer, the SOC observer including a hysteresis model to account for differential hysteresis in the Li+ battery cells;
- wherein the at least one processor is arranged to effect charging and discharging of the one or more Li+ battery cells to execute the hysteresis model;
- wherein the hysteresis model dynamically models direction-dependent VOC behavior of the one or more Li+ battery cells based upon a direction of current flow and a state of charge;
- and
- wherein the SOC observer determines the SOC for the one or more Li+ battery cells based upon the VOC across the one or more Li+ battery cells.
Dependencies are inferred from the claim text.