Abstract: 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.

Abstract: Dynamically monitoring of an electrically-isolated power bus for a DC power system is described, and includes dynamically monitoring voltage and current on the power bus to determine a variation in the voltage on the power bus. When the variation in the voltage on the power bus is less than a threshold, an active positive isolation resistance term and an active negative isolation resistance term are determined. A first voltage balance term is determined based upon a ratio of the active positive isolation resistance term and the active negative isolation resistance term. A dynamic positive isolation resistance term and a dynamic negative isolation resistance term are determined based upon the active negative isolation resistance term. A fault associated with the power bus is determined based upon the dynamic positive isolation resistance term and the dynamic negative isolation resistance term.

Abstract: A method of controlling temperature of a coolant supplied to a battery pack includes detecting a request for charging the battery pack, and commanding, via the electronic controller, a rate of charge of the battery pack. The method also includes determining the dew point inside the battery pack during the charging. The method additionally includes commanding a supply of coolant to the battery pack while the battery pack is charging. The method also includes regulating a temperature of the coolant to maintain the battery pack above the determined dew point during the charging. The method may further include maximizing the rate of charge at the regulated temperature of the coolant. A battery system employing an electronic controller configured to perform such a method, and a motor vehicle using such a battery system are also within the scope of the present disclosure.

Abstract: Dynamically monitoring of an electrically-isolated power bus for a DC power system is described, and includes dynamically monitoring voltage and current on the power bus to determine a variation in the voltage on the power bus. When the variation in the voltage on the power bus is less than a threshold, an active positive isolation resistance term and an active negative isolation resistance term are determined. A first voltage balance term is determined based upon a ratio of the active positive isolation resistance term and the active negative isolation resistance term. A dynamic positive isolation resistance term and a dynamic negative isolation resistance term are determined based upon the active negative isolation resistance term. A fault associated with the power bus is determined based upon the dynamic positive isolation resistance term and the dynamic negative isolation resistance term.

Abstract: A vehicle system including a propulsion system coupled to a drive wheel and a friction brake configured to apply braking torque to a vehicle wheel is described. Operation thereof includes an instruction set that is executable to monitor vehicle speed, vehicle grade, and an operator braking request, and execute instructions upon achieving a vehicle speed that is less than a threshold speed. The instructions include controlling, via the friction brake, the braking torque to achieve a desired vehicle speed, and determining an operator acceleration request and the vehicle grade. The controller determines a minimum vehicle grade-based operator acceleration request, and releases the friction brake only when the operator acceleration request is greater than the minimum vehicle grade-based operator acceleration request.

Abstract: In one example implementation according to aspects of the present disclosure, a DC-to-DC converter for transmitting electricity from a first power device at a first voltage and current combination to a second power device at a second voltage and current combination is provided. The DC-to-DC converter comprises a first electrical conductor having a first end and a second end and a second electrical conductor having a third end and a fourth end. The first end and the third end are electrically coupled to the first power device and the second end and the fourth end are electrically coupled to the second power device. The first electrical conductor and the second electrical conductor together provide circuit inductance substantially equivalent to and in place of an inductor having a circular winding.

Abstract: A vehicle system including a propulsion system coupled to a drive wheel and a friction brake configured to apply braking torque to a vehicle wheel is described. Operation thereof includes an instruction set that is executable to monitor vehicle speed, vehicle grade, and an operator braking request, and execute instructions upon achieving a vehicle speed that is less than a threshold speed. The instructions include controlling, via the friction brake, the braking torque to achieve a desired vehicle speed, and determining an operator acceleration request and the vehicle grade. The controller determines a minimum vehicle grade-based operator acceleration request, and releases the friction brake only when the operator acceleration request is greater than the minimum vehicle grade-based operator acceleration request.

Abstract: An electrical system includes cables, a DC charge connector, first and second battery modules, a splice device, and a controller. Each battery module has first, second, third, and fourth electrical connectors receiving a respective one of the cables. The battery modules are connected to each other via the cables, and further have first, second, third, and fourth switches that connect battery cell strings to one or more connectors. The charge connector is connected to one of the cables between the first electrical connectors. The splice device connects the charge connector to the first connector of the first battery module and to a pair of the cables. A charging current may be split between the battery modules. The controller selectively establishes parallel charging, parallel drive, and separate drive and charging modes for each battery module. The system may have an independent drive mode.

Abstract: An electrical system includes cables, a DC charge connector, first and second battery modules, a splice device, and a controller. Each battery module has first, second, third, and fourth electrical connectors receiving a respective one of the cables. The battery modules are connected to each other via the cables, and further have first, second, third, and fourth switches that connect battery cell strings to one or more connectors. The charge connector is connected to one of the cables between the first electrical connectors. The splice device connects the charge connector to the first connector of the first battery module and to a pair of the cables. A charging current may be split between the battery modules. The controller selectively establishes parallel charging, parallel drive, and separate drive and charging modes for each battery module. The system may have an independent drive mode.

Abstract: A discharge control system of a vehicle includes a traction power inverter module (TPIM) configured to convert a first direct current (DC) voltage output by a first battery to alternating current (AC) power and apply the AC power to an electric motor. An accessory power module (APM) is configured to convert the first DC voltage into a second DC voltage of a second battery. A voltage calculation module is configured to, when the first DC voltage is less than an operation threshold voltage of the APM, determine the second DC voltage based on a function of the first DC voltage and the operation threshold voltage. A diagnostic module is configured to indicate whether a discharge fault is present. A discharge control module is configured to, when the discharge fault is present, based the first DC voltage and the second DC voltage, selectively control operation of the TPIM and the APM.