Patent application number | Description | Published |
20150197158 | PERTURBATIVE INJECTION FOR BATTERY PARAMETER IDENTIFICATION - A battery system includes a traction battery and at least one controller that implement a model of the traction battery. The system may monitor current input and voltage output of the traction battery. The at least one controller may inject a plurality of current signals into the battery when it detects the input current to be approximately zero and a corresponding terminal voltage to be generally constant. Each of the injected current signals has a discrete frequency. The controller may measure voltage responses to the injected currents indicative of impedances of the traction battery at the discrete frequencies. The controller may output parameters representing an equivalent circuit model of the traction battery based on the impedances, and operate the battery based on the parameters. | 07-16-2015 |
20150197159 | IMPEDANCE BASED BATTERY PARAMETER ESTIMATION - A hybrid powertrain system includes a battery cell and at least one controller programmed to output an average internal resistance of the cell for a sliding window time period. A mean electrical impedance is calculated by the controller based on a quotient of a Fast Fourier Transform (FFT) of a voltage output by the cell and a FFT of current input to the cell. An average internal resistance is calculated by the controller based on the mean electrical impedance. The controller may further control the cell according to the average internal resistance. | 07-16-2015 |
20150197164 | RECEDING HORIZON REGRESSION ANALYSIS FOR BATTERY IMPEDANCE PARAMETER ESTIMATION - A hybrid vehicle includes a battery pack having one or more cells and a controller configured to continuously update battery model parameter values based on generalized linear regression analysis. The analysis updates the parameters using a dataset of independent variable vectors and a dependent variable vector constructed from a series of input currents to the battery pack and corresponding voltage responses of the battery pack that fall within a moving window. | 07-16-2015 |
20150258907 | FREQUENCY BASED BATTERY MODEL PARAMETER ESTIMATION - A hybrid powertrain system includes a battery and at least one controller. The at least one controller is configured to determine instantaneous battery power limits during operation of the system using filtered battery voltage signals and current input signals. The at least one controller is further configured to separate medium-to-high frequency dynamics of the measured battery voltage. The filtering process, in certain examples, is realized using a low pass filter or a high pass filter. The at least one controller is further configured to correlate the medium-to-high frequency loads to estimate battery parameters and determine battery dynamics using, in one example, an Extended Kalman Filter. | 09-17-2015 |
20150321576 | Battery Cell State of Charge Estimation - Hybrid and electric vehicles include a traction battery including many interconnected cells. Effective battery control, such as cell balancing, may rely on an accurate state of charge value for each of the cells. A method to reduce the computational effort of the state of charge calculation is developed. An accurate pack level state of charge calculation is implemented and represents the average cell state of charge. An average cell voltage is based on a pack voltage measurement. A state of charge difference is calculated for each cell based on a difference between a cell voltage and the average cell voltage. The state of charge difference utilizes the pack state of charge and a characteristic voltage and state of charge relationship for the cell. The cell state of charge is the sum of the pack state of charge and the state of charge difference. | 11-12-2015 |
20150326038 | SYSTEM AND METHOD FOR BATTERY POWER MANAGEMENT - A battery management system includes a battery pack and a controller. The controller is configured to receive pack terminal voltage and current data. In response, the controller may estimate battery model parameters in an equivalent circuit model and output state variable values indicative of fast and slow dynamics of the voltage responses. The controller may also output parameter values indicative of feedback gains to compute a current limit in a state feedback structure. The controller may further estimate battery current limits based on the state variable values and the feedback gains to control operation of the battery pack. | 11-12-2015 |
20150355283 | Method and System for Estimating Battery Model Parameters to Update Battery Models Used for Controls - A powertrain having a traction battery is operated according to performance variables of the battery based on state variables of a reduced-order electrochemical model of the battery. The state variables are estimated by an estimator based on the battery model. A parameter of the battery model characterizing dynamics of the state variables with respect to battery operating conditions is updated by the estimator based on the battery model. | 12-10-2015 |
20150355615 | Method and System for Battery State of Charge Estimation - A powertrain having a Lithium-ion (Li-ion) traction battery including solid active particles is operated according to a state of charge of the battery based on an estimated Li-ion concentration profile of a representative solid active particle of a reduced-order model of the battery. The concentration profile is estimated according to the reduced-order model from the measured voltage and current of the battery. | 12-10-2015 |
20160001670 | SYSTEM AND METHOD FOR BATTERY MANAGEMENT - A vehicle includes a battery pack and at least one controller. The at least one controller is programmed to provide injection current inputs to a model configured to simulate, in response to the inputs, terminal voltage outputs of the battery pack. The at least one controller is further programmed to output power limits for the battery pack based on a regression of the injection current inputs and terminal voltage outputs. | 01-07-2016 |
20160001672 | EQUIVALENT CIRCUIT BASED BATTERY CURRENT LIMIT ESTIMATIONS - A battery system includes a plurality of battery cells and a controller. The controller outputs a plurality of current limits for the cells, and controls operation of the cells according to the current limits. Each of the current limits has a different time duration and is based on state variables from an equivalent circuit model of the cells. The state variables are based on terminal voltage and output current data associated with the cells. | 01-07-2016 |
20160006087 | Reduced Order Battery Thermal Dynamics Modeling for Controls - A vehicle includes a traction battery that is comprised of a number of cells. A controller operates the traction battery according to a temperature for each of the cells. The temperature is based on a number of coefficients representing a contribution of at least one cell boundary thermal condition and a heat generated in the cell to a steady-state temperature at a predetermined location within the cell. The contributions may be filtered to predict a dynamic response of the temperature to changes in the boundary thermal conditions and the heat generated in the cell. The coefficients may be derived from a full-order model. The resulting reduced-order model requires less execution time while achieving accuracy similar to the full-order model. In addition, a range of characteristic temperatures may be obtained for each cell. | 01-07-2016 |
20160006275 | SYSTEM AND METHOD FOR BATTERY OPEN CIRCUIT VOLTAGE ESTIMATION - A vehicle includes a battery pack and at least one controller. The at least one controller outputs open circuit voltage data for a given state of charge of the battery pack based on model parameters of battery pack positive and negative electrodes represented by normalized Li-ion concentrations at zero and one hundred percent states of charge, and model parameters of at least two open circuit voltages each associated with a different state of charge. | 01-07-2016 |
20160023566 | REDUCED ORDER ELECTROCHEMICAL BATTERY MODEL FOR VEHICLE CONTROL - A vehicle battery system includes a traction battery. The traction battery includes at least one cell having an anode, a cathode and an electrolyte therebetween defining a solid-electrolyte interface including an anode solid-electrolyte interface and a cathode solid-electrolyte interface. The vehicle further includes at least one controller that operates the traction battery according to a battery performance variable. The battery performance variable is based on an effective diffusion coefficient of the solid-electrolyte interface, an effective Ohmic resistance of the battery, a Li-ion concentration that is derived from a response to a current profile, and an operating battery current. | 01-28-2016 |
20160023567 | TEMPERATURE DEPENDENT ELECTROCHEMICAL BATTERY MODEL FOR VEHICLE CONTROL - A vehicle battery system includes a traction battery. The traction battery includes at least one cell having an anode, a cathode and an electrolyte therebetween defining a solid-electrolyte interface including an anode solid-electrolyte interface and a cathode solid-electrolyte interface. The system also includes at least one controller that operates the traction battery according to a battery operational variable that is based on a temperature dependent diffusion coefficient of the solid-electrolyte interface, a temperature dependent Ohmic resistance, a Li-ion concentration that is derived from a response to a current profile, and an operating battery current. | 01-28-2016 |
20160023568 | INTERPOLATION OF METAL-ION CONCENTRATIONS IN A BATTERY MODEL FOR VEHICLE CONTROL - A vehicle battery system includes a traction battery. The traction battery includes at least one cell having an anode, a cathode, and an electrolyte therebetween defining a solid-electrolyte interface including an anode solid-electrolyte interface and a cathode solid-electrolyte interface. The system further includes at least one controller programmed to operate the battery according to a battery state of charge that is based on a metal-ion concentration at unevenly discretized locations along an axis of at least one electrode of the battery and derived from a battery model having an associated battery current profile input. | 01-28-2016 |
20160023569 | BATTERY POWER CAPABILITY ESTIMATION BASED ON REDUCED ORDER ELECTROCHEMICAL MODELS - A vehicle includes a battery made up of cells having positive and negative electrodes. A controller operates the battery according to a battery power limit based on a reduced order electrochemical model of the battery. The model includes states that are effective metal-ion concentrations at locations within the electrodes. A battery power limit is based on the metal-ion concentrations and parameters of a system matrix that includes coefficients indicative of a contribution of each of the concentrations to a gradient defined by the concentrations. The parameters are eigenvalues of the system matrix. The power limit is further derived by transforming the system such that the system matrix is expressed as a function of a diagonal matrix. | 01-28-2016 |
20160059727 | METHOD FOR BATTERY STATE OF CHARGE ESTIMATION - A battery management system includes at least one controller programmed to, in response to a battery current becoming approximately zero, output an open-circuit voltage based on a sequence of battery terminal voltages measured during a time interval in which the battery current remains approximately zero and while a charge polarization voltage is decreasing. The open-circuit voltage may be further based on a non-linear regression of the sequence of battery terminal voltages. The non-linear regression may minimize a mean-squared error between the battery terminal voltages and corresponding battery terminal voltage estimates. The at least one controller may command the battery current to zero for the time interval. The battery management system may be included in a vehicle with a traction battery. | 03-03-2016 |
20160059728 | Method of Operating Vehicle Powertrain Based on Prediction of How Different Chemical Type Batteries Connected in Parallel will Operate to Output Demanded Current - A powertrain having a battery system including at least two batteries of different chemical types connected in parallel is operated according to predicted responses of the batteries to a demanded current command for the battery system to output a demanded current. The battery responses are predicted directly from the demanded current using a backward-looking model of the battery system. | 03-03-2016 |