Abstract: An accessory power system includes an accessory power module having primary power switches, a transformer, and secondary rectifiers. The primary power switches are electrically connected to the high-voltage bus, and the secondary rectifiers are electrically connected to the low-voltage bus. A peak detector is coupled to the high-voltage bus. A controller is in communication with the peak detector circuit, and operatively connected to the primary power switches. The controller dynamically monitors, via the peak detector circuit, a ripple voltage of the high-voltage bus, compares the monitored voltage with a maximum threshold voltage, and disables the plurality of primary power switches when the ripple voltage of the high-voltage bus is greater than the maximum threshold voltage, and reactivates the primary power switches when the ripple voltage of the high-voltage bus is less than the maximum threshold voltage.

Abstract: An accessory power system includes an accessory power module having primary power switches, a transformer, and secondary rectifiers. The primary power switches are electrically connected to the high-voltage bus, and the secondary rectifiers are electrically connected to the low-voltage bus. A peak detector is coupled to the high-voltage bus. A controller is in communication with the peak detector circuit, and operatively connected to the primary power switches. The controller dynamically monitors, via the peak detector circuit, a ripple voltage of the high-voltage bus, compares the monitored voltage with a maximum threshold voltage, and disables the plurality of primary power switches when the ripple voltage of the high-voltage bus is greater than the maximum threshold voltage, and reactivates the primary power switches when the ripple voltage of the high-voltage bus is less than the maximum threshold voltage.

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.

Abstract: A topology for electric power distribution in a vehicle includes a high-voltage bus connected to a DC-DC electric power converter that is connected to a low-voltage DC load. The DC-DC electric power converter includes a high-voltage switching circuit, a transformer, and a low-voltage rectifier. The high-voltage switching circuit includes first and second switches arranged in series between positive and negative legs of the high-voltage electric power bus at a first node that connects to a leg of an inductor of the transformer. A controller receives a command to discharge the high-voltage electric power bus, and in response, controls a first gate circuit to operate a first switch in a linear mode, and controls a second gate circuit to operate a second switch in a pulsewidth-modulated mode. A duty cycle for the pulsewidth-modulated operation of the second switch is determined based upon the magnitude of electric current.

Abstract: A topology for electric power distribution in a vehicle includes a high-voltage bus connected to a DC-DC electric power converter that is connected to a low-voltage DC load. The DC-DC electric power converter includes a high-voltage switching circuit, a transformer, and a low-voltage rectifier. The high-voltage switching circuit includes first and second switches arranged in series between positive and negative legs of the high-voltage electric power bus at a first node that connects to a leg of an inductor of the transformer. A controller receives a command to discharge the high-voltage electric power bus, and in response, controls a first gate circuit to operate a first switch in a linear mode, and controls a second gate circuit to operate a second switch in a pulsewidth-modulated mode. A duty cycle for the pulsewidth-modulated operation of the second switch is determined based upon the magnitude of electric current.

Abstract: An electrified powertrain system for a vehicle includes an electric machine coupled to a driveline. An inverter controller communicates directly with an auxiliary power module. An ignition module indicates either a key-on state or a key-off state. When the ignition module is in a key-off state, a low-power DC/DC converter generates an output voltage originating on the high-voltage DC bus having a magnitude sufficient to activate the inverter controller. The inverter controller detects a key-off uncontrolled generator (UCG) mode. The inverter controller directly communicates detection of the key-off UCG mode to the auxiliary power module. The inverter controller controls the inverter. The auxiliary power module supplies electric power to operate low-voltage electrically-powered powertrain actuators.

Abstract: An electrified powertrain system for a vehicle includes an electric machine coupled to a driveline. An inverter controller communicates directly with an auxiliary power module. An ignition module indicates either a key-on state or a key-off state. When the ignition module is in a key-off state, a low-power DC/DC converter generates an output voltage originating on the high-voltage DC bus having a magnitude sufficient to activate the inverter controller. The inverter controller detects a key-off uncontrolled generator (UCG) mode. The inverter controller directly communicates detection of the key-off UCG mode to the auxiliary power module. The inverter controller controls the inverter. The auxiliary power module supplies electric power to operate low-voltage electrically-powered powertrain actuators.

Abstract: A method sustains auxiliary power generation aboard a mild hybrid electric vehicle (HEV) in response to a high-voltage (HV) electrical fault condition and executes one of a pair of default limp-home modes depending on the state of the engine at the time of the fault. Each limp-home mode sustains auxiliary power generation during the fault, and at least one mode charges capacitors in the HV bus circuit to provide magnetizing current to a motor generator unit (MGU). An HEV includes a controller and algorithm for sustaining auxiliary power generation during the above fault condition, with the algorithm adapted to control output of an auxiliary power module (APM) and execute one of a pair of default limp-home modes, including a mode in which the APM charges the capacitors to enable a power inverter module (PIM) to provide an initial excitation current to the MGU after the starter motor restarts the engine.

Abstract: A method sustains auxiliary power generation aboard a mild hybrid electric vehicle (HEV) in response to a high-voltage (HV) electrical fault condition and executes one of a pair of default limp-home modes depending on the state of the engine at the time of the fault. Each limp-home mode sustains auxiliary power generation during the fault, and at least one mode charges capacitors in the HV bus circuit to provide magnetizing current to a motor generator unit (MGU). An HEV includes a controller and algorithm for sustaining auxiliary power generation during the above fault condition, with the algorithm adapted to control output of an auxiliary power module (APM) and execute one of a pair of default limp-home modes, including a mode in which the APM charges the capacitors to enable a power inverter module (PIM) to provide an initial excitation current to the MGU after the starter motor restarts the engine.