Abstract: A traction battery controller of an electrified vehicle dynamically adjusts an estimation gain based on a state-of-charge (SOC) of the traction battery and controls the vehicle according to an operating characteristic of the traction battery estimated from an equivalent circuit model of the traction battery that depends on the estimation gain. The controller may reduce the estimation gain while the SOC is low or high and may otherwise maintain the SOC. The controller may dynamically adjust the estimation gain based further on a temperature of the traction battery. The operating characteristic may be a power capability of the traction battery or an updated SOC of the traction battery.

Abstract: A method for detecting a capacity of a battery, such as a traction battery of an electrified vehicle, includes varying a charge current provided to the battery and measuring a terminal voltage of the battery as the charge current is being varied. An estimator, that utilizes voltage feedback based on a model of the battery to provide state and parameter estimations of the battery, is driven with the terminal voltage to estimate a state-of-charge (SOC) of the battery. The capacity of the battery may be detected based in part on the SOC.

Abstract: A vehicle includes a battery, an electric machine, and a controller. The battery has a state of charge. The electric machine is configured to draw electrical power from the battery to propel the vehicle in response to an acceleration request and to deliver electrical power to the battery to recharge the battery. The controller is programmed to adjust an estimation of battery state of charge based on a feed forward control that includes a coulomb counting algorithm, a first feedback control that includes a first battery model, and a second feedback control that includes a second battery model. The controller is further programmed to control the electrical power flow between the battery and the electric machine based on the estimation of the state of charge of the battery.

Abstract: A system includes at least one load in a vehicle, a battery electrically connected to the load, a power source electrically connected to the load, and a computer communicatively connected to the power source. The computer is programmed to reduce a voltage supplied by the power source to the load so that the battery discharges to supply power to the load, and then, in response to an electrical quantity of the system being outside an electrical-quantity range while the battery is discharging, perform a minimal risk condition or prevent the vehicle from movably operating.

Abstract: A vehicle includes a battery, an electric machine, and a controller. The battery has a state of charge. The electric machine is configured to draw electrical power from the battery to propel the vehicle in response to an acceleration request and to deliver electrical power to the battery to recharge the battery. The controller is programmed to adjust an estimation of battery state of charge based on a feed forward control that includes a coulomb counting algorithm, a first feedback control that includes a first battery model, and a second feedback control that includes a second battery model. The controller is further programmed to control the electrical power flow between the battery and the electric machine based on the estimation of the state of charge of the battery.

Abstract: A system includes at least one load in a vehicle, a battery electrically connected to the load, a power source electrically connected to the load, and a computer communicatively connected to the power source. The computer is programmed to reduce a voltage supplied by the power source to the load so that the battery discharges to supply power to the load, and then, in response to an electrical quantity of the system being outside an electrical-quantity range while the battery is discharging, perform a minimal risk condition or prevent the vehicle from movably operating.

Abstract: Method and apparatus are disclosed for monitoring a vehicle power supply system having a primary and a secondary power source. An example vehicle includes a primary power source, a secondary power source comprising a low voltage battery, and a processor. The processor is configured for reducing an output of the primary power source, determining an operational characteristic of the low voltage battery while the output of the primary power source is reduced, and providing an alert based on the operational characteristic.

Abstract: A high voltage battery pack comprises series-connected battery units, each separately powering a respective DC/DC converter. The converter outputs are coupled in parallel to supply a low-voltage DC bus. A central module has 1) an outer loop controller generating a target current to regulate the bus voltage and 2) an allocator distributing the target current via allocated current commands for respective converters. Local controllers each regulate an output current of a respective converter. The allocator identifies battery units having a predetermined deviation from a reference metric that characterizes the battery pack, allocates reverse currents to respective converters for the identified battery units, and increases the target current commanded for the DC/DC converters not allocated to have a reverse current by the allocated reverse currents. Battery units with extremely low or high states as compared with the other units are quickly balanced, thereby improving overall performance of the battery pack.

Abstract: A vehicle includes a traction battery comprising a plurality of cells. The vehicle also includes a plurality of power converters each electrically coupled between a corresponding group of cells and an electrical bus. A controller is programmed to allocate current demand to the power converters and operate the power converters to minimize energy consumption and losses.

Abstract: A vehicle includes a traction battery comprising a plurality of cells. The vehicle also includes a plurality of power converters each electrically coupled between a corresponding group of cells and an electrical bus. A controller is programmed to allocate current demand to the power converters and operate the power converters to minimize energy consumption and losses.

Abstract: A high voltage battery pack comprises series-connected battery units, each separately powering a respective DC/DC converter. The converter outputs are coupled in parallel to supply a low-voltage DC bus. A central module has 1) an outer loop controller generating a target current to regulate the bus voltage and 2) an allocator distributing the target current via allocated current commands for respective converters. Local controllers each regulate an output current of a respective converter. The allocator identifies battery units having a predetermined deviation from a reference metric that characterizes the battery pack, allocates reverse currents to respective converters for the identified battery units, and increases the target current commanded for the DC/DC converters not allocated to have a reverse current by the allocated reverse currents. Battery units with extremely low or high states as compared with the other units are quickly balanced, thereby improving overall performance of the battery pack.

Abstract: A traction battery of a vehicle includes a temperature compensated passive wireless surface acoustic wave sensor within the traction battery and a controller. The temperature compensated passive wireless surface acoustic wave sensor is configured to receive a broadcast signal and transmit a reflected signal. The controller is programmed to transmit the broadcast signal and receive the reflected signal, and based on a difference in phase and amplitude between the broadcast and reflected signals indicative of an increase in pressure within the traction battery, stop charging the traction battery.

Abstract: Method and apparatus are disclosed for monitoring a vehicle power supply system having a primary and a secondary power source. An example vehicle includes a primary power source, a secondary power source comprising a low voltage battery, and a processor. The processor is configured for reducing an output of the primary power source, determining an operational characteristic of the low voltage battery while the output of the primary power source is reduced, and providing an alert based on the operational characteristic.

Abstract: An apparatus for model predictive control (“MPC”) is disclosed. A method and system also perform the functions of the apparatus. The apparatus includes a measurement module that receives battery status information from one or more sensors receiving information from a battery cell, and a Kalman filter module that uses a Kalman filter and the battery status information to provide a state estimate vector. The apparatus includes a battery model module that inputs the state estimate vector and battery status information into a battery model and calculates a battery model output, the battery model representing the battery cell, and an MPC optimization module that inputs one or more battery model outputs and an error signal in a model predictive control algorithm to calculate an optimal response. The optimal response includes a modification of the error signal.

Abstract: An apparatus includes a battery state module that determines a battery state of each of a plurality of battery cells forming a battery unit. A battery state includes a health of the battery cell. A battery state of a battery cell differs from a battery state of other battery cells of the battery unit. Each battery cell is connected to a shared bus through a bypass converter that provides power from the battery cell to the shared bus. A charge/discharge modification module determines, based on battery state, an amount to vary a charging characteristic for each battery cell compared to a reference charging characteristic. Each charging characteristic varies as a function of a reference state. A charge/discharge module adjusts charging/discharging of a battery cell of the battery unit based on the charging characteristic of the battery cell.

Abstract: An electrified vehicle high voltage battery pack has series-connected battery units or cells combining to provide the high voltage. To power a low voltage bus (e.g., for low voltage accessories or charging a low voltage battery) in a balanced manner, a plurality of DC/DC converters each has an input coupled to a respective battery unit and the converters have respective outputs coupled in parallel to the low voltage bus. A first loop controller receives an actual bus voltage. The first controller generates a target current in response to the bus voltage adapted to regulate the actual bus voltage to a target voltage less than the high voltage. A second controller distributes the target current into a plurality of allocated current commands for respective converters according to respective states of charge of the battery units connected to the converters.

Abstract: A vehicle includes a traction battery and a controller coupled to the traction battery and having a memory, the controller being programmed to control the traction battery based on a difference between a total resistance indicated by voltage and current at a first operating condition and a battery cell resistance associated with the first operating condition previously stored in the memory, the difference being indicative of a wiring resistance associated with electrical connectors such as wires, cables, bus bars, and the like of the battery. The battery or the vehicle may be controlled in response to the adaptively determined wiring resistance by adjusting subsequent voltage or current determinations used to determine state of charge and battery capacity and/or to control charging or discharging of the battery and selection of various vehicle operating modes.

Abstract: An electrified vehicle has a battery pack comprising series-connected battery units providing a main voltage. To supply a lower voltage bus equally from all battery units, a plurality of DC/DC converters are powered by respective units and have their outputs in parallel. A central module has an outer loop controller generating a target current to regulate the bus voltage to a predetermined voltage and has an allocator distributing the target current into a plurality of allocated current commands according to respective states of charge of the battery units. A plurality of local controllers each adjusts a current of a respective DC/DC converter. Each local controller receives a respective allocated current command as a respective feedforward control variable. Each local controller uses an error between the bus voltage and the predetermined voltage to be integrated as a respective feedback control variable only when the error is above a threshold.

Abstract: A hybrid or electric vehicle includes a traction battery to store and provide energy for the vehicle. The traction battery includes a number of battery cells. For effective operation of the traction battery, operating parameters, such as state of charge and battery power limits, may need to be known. The operating parameters may be a function of battery cell voltage and impedance parameters. A parameter estimation scheme may use measured cell voltages and a measured traction battery current as inputs. A current measurement bias may be modeled that incorporates measurement bias caused by asynchronous current and voltage measurements. The current measurement bias may be estimated for each cell and the value may differ between cells.

Abstract: A diagnostic method for contact resistance failure includes estimating electrical contact surface resistance of at least one contactor, determining a faulted status of the at least one contactor and indicating the faulted status of the at least one contactor if the at least one contactor is in the faulted status.