Gm Global Technolgoy Operations, Inc.

Yanyan Zhang

Joseph Mussro

Sriram Ganapathy

Xingcheng Xiao

Brian James Koch

Bruce Jeffrey Clingerman

Daniel J Wilson

Donald H Keskula

Jing Gao

Daniel C Di Fiore

Kiran Mallavarapu

Kris Sevel

Zhe Li

Loren Devries

Ryan B Moulliet

Andrew M Zettel

Davis H Rossman

Chetan Powar

Sangam Rawat

Ziad Shounia

Methods and systems are provided for monitoring a state of health (SOH) of a battery system of an electric vehicle (EV). A projected SOH value of the battery system at one of a future vehicle age and a future total EV mileage is generated. The projected SOH value is based in part on a current SOH value and historical SOH values associated with use of the battery system to supply power to at least one of an offboard vehicle load and an onboard accessory load. A determination is made regarding whether the projected SOH value is less than a SOH threshold at the one of the future vehicle age and the future total EV mileage. A customer SOH alert regarding use of the battery system to supply power to the at least one of the offboard vehicle load and the onboard accessory load is generated based on the determination.

Systems and methods for monitoring a state of health of a battery system of an electric vehicle

A method, system, and motor vehicle for controlling a direct-current fast-charging process of a battery system are provided that significantly improves performance of the direct-current fast-charging process and minimizes condensation issues by utilizing lower coolant temperature for a short duration when a rechargeable energy storage system cell temperature is greater than a specific temperature threshold. The rechargeable energy storage system cell temperature, a rechargeable energy storage system state of charge a rechargeable energy storage system voltage, and a rechargeable energy storage system direct-current fast-charging current are utilized to determine when to utilize the lower coolant temperature when the rechargeable energy storage system cell temperature is greater than a specific temperature threshold instead of using a lower coolant temperature from the beginning of the direct-current fast-charging process.

DCFC smart cooling strategy

A battery cell includes an anode, a cathode, a liquid electrolyte, and a battery cell case. The battery cell case is configured to house the anode, the cathode, and the liquid electrolyte and includes a case interior wall arranged proximate one of the anode and the cathode, a battery case ceiling, and a battery case floor catching and collecting the liquid electrolyte due to force of gravity. The case interior wall defines a pattern of surface tension varying between hydrophobic and hydrophilic along the case interior wall between the battery case floor and the battery cell ceiling. The pattern of surface tension thereby facilitates self-propulsion of the liquid electrolyte in opposition to the force of gravity and a predetermined distribution of the liquid electrolyte along the battery cell wall.

Battery cell enclosure with anti-gravity electrolyte distribution

System and methods for setting pressure limits for an air supply of a fuel cell ('FC') system are presented. Certain embodiments disclosed herein may allow a FC system to calculate a minimum and a maximum FC stack cathode inlet pressure based on different operating conditions while ensuring that the FC stack receives a desired air flow. Further embodiments disclosed herein may allow a FC system to maintain a cathode inlet air pressure within a range that protects an associated compressor from entering surge and/or overheating conditions.

Systems and methods to determine cathode inlet pressure limits in a fuel cell system

System and methods for detecting surge conditions in a compressor system are presented. In some embodiments, a method for detecting surge conditions may include receiving a plurality of flow measurements relating to a flow rate through the compressor system. Amplitude calculations may be performed based on at least one of the plurality of flow measurements to identify a possible surge condition. Frequency calculations may also be performed to identify a possible surge condition. A surge condition may be detected based on the results of the amplitude calculation and the frequency calculation and, in response, a surge detection control signal may be generated.

Systems and methods for detecting compressor surge

Disclosed herein are systems and methods for monitoring and controlling a flow of air within a fuel cell stack. The fuel cell stack may include an air supply path to conduct a flow of air through the fuel cell. Sensors may be configured to determine parameters associated with the air supply path, such as pressure, flow rate, etc. A modeling system may further be configured to determine a modeled parameter associated with the air supply path. A control system may receive input from the one or more sensors and the modeling system to generate a baseline based on the measured parameter and the modeled parameter, determine a difference between the measured parameter and the modeled parameter, determine a change of the difference with respect to the baseline, determine that the change satisfies a criterion, and selectively implement a corrective action based upon satisfaction of the criterion.

Systems and methods to monitor and control a flow of air within a fuel cell stack

A system and method for utilizing a pressurized volume of oxygen in a cathode plumbing of a fuel cell system. The system and method includes calculating an air/oxygen balance that is based on an air balance and an oxygen balance in the cathode plumbing. The system and method further include determining the number of moles of oxygen available for fuel cell chemical reactions using the calculated air/oxygen balance and drawing current from a fuel cell stack using the moles of oxygen available for fuel cell chemical reactions.

FCS overall efficiency by using stored cathode oxygen during down-transients

Systems and methods to control compressor recirculation of a reactant in a fuel cell system. A recirculation valve flow setpoint value for a gas flow to the recirculation valve is calculated based on a received cathode flow setpoint. A value corresponding to a predicted recirculation valve position is generated, and can be used as a control command for changing the position of the recirculation valve to reduce the valve response time during operational transients of the fuel cell system.

Systems and methods for controlling a compressor recirculation valve

A method and device for predictively controlling the speed of a compressor used in conjunction with a fuel cell stack. Feedforward command signals are generated based on fuel cell stack setpoints that are based on stack humidification requirements. A pressure drop model uses these setpoints to determine a compressor outlet pressure setpoint change brought about by an operational transient. A recursive approach is used to solve for one or more future or desired compressor operating conditions. The results of this recursive approach are used to determine the feedforward speed command of the compressor, where known operational parameters (such as can be found on a compressor map) may be used. This permits rapid changes in compressor speed to comply with the new operating point of the fuel cell system that is brought about by the operational transient.

Predictive cathode compressor speed control in a fuel cell power system

Devices and methods to control a cathode backpressure valve and a bypass valve in a vehicle fuel cell system. A feedforward-based control strategy is used to control the cathode backpressure valve. The control over the bypass valve is integrated into the control over the cathode backpressure valve. Such a control strategy acts in a predictive manner to improve valve response to transitory cathode pressure and bypass flow split setpoints in the system.

Cathode flow split control and pressure control for a vehicle fuel cell power system

Systems and methods to control fuel cell stack pressure through a cathode backpressure valve. A flow offset value is used as a capacitance term during transient operational conditions to account for discrepancies between the stack flow setpoint and the actual stack flow. The capacitance term is based on operational parameters, including stack pressure changes, stack coolant temperature and stack volume. The additional flow produced by the capacitance terms may be fed, along with pressure drop models and a valve position model to provide a more accurate prediction of valve position.

Cathode pressure control utilizing a capacitance model

Systems and methods to mitigate surge conditions in a compressor of a vehicle fuel cell system. A first surge mitigation strategy regulates a cathode backpressure valve, if the compressor is operating at or above a threshold speed. A second surge mitigation strategy regulates a recirculation valve if the compressor is operating below the threshold speed. In one form, a feedback-based control may be used as part of a larger feedforward-based control strategy such that the mitigation is part of a reactive control strategy. The strategy may additionally be implemented in a processor-based controller.

Reactive compressor surge mitigation strategy for a fuel cell power system

A system and method for determining the maximum allowed stack current limit rate for a fuel cell stack that considers cell voltage. The method includes estimating a fuel cell stack voltage based on a fuel cell resistance value, stack variables and a current request signal. The fuel cell resistance value can be modeled based on stack temperature and stack relative humidity. The stack variables can include exchange current density and mass transfer coefficient. The method then uses the estimated fuel cell voltage and a look-up table based on estimated voltage to determine a current rate limit value for changing the current of the stack. The method then adds the current rate limit value and the current request signal to obtain the current set-point.

Method to improve fuel cell system performance using cell voltage prediction of fuel cell stack

A system for estimating parameters of a fuel cell stack. The system includes a stack health monitor for monitoring minimum cell voltage, stack voltage and current density of the fuel cell stack. The stack health monitor also indicates when a predetermined minimum cell voltage threshold level has been achieved. The system further includes a controller configured to control the fuel cell stack, where the controller determines and records the average fuel cell voltage. The controller generates and stores artificial data points proximate to the one or more predetermined minimum cell voltage threshold levels each time the minimum cell voltage drops below the one or more predetermined minimum cell voltage threshold levels so as to provide an estimation of the fuel cell stack parameters including a minimum cell voltage trend and a minimum cell voltage polarization curve.

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Victor, NY, United States of America

Yanyan Zhang