Abstract: Systems and methods of aircraft thrust management are provided. For example, a propulsion system for an aircraft comprises a fuel cell assembly comprising a fuel cell, a turbomachine, and a controller comprising memory and one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the propulsion system to perform operations including receiving data indicative of a propulsion system thrust discrepancy and modifying an output of the fuel cell in response to receiving data indicative of the propulsion system thrust discrepancy. Modifying the fuel cell output may include modifying output products, an electrical power output, or both of the fuel cell to balance the thrust provided by the propulsion system.

Abstract: An AC electrical system for a vehicle and methods of operating the same are provided. In one aspect, an AC electrical system includes a first electric machine mechanically coupled with a first spool of a gas turbine engine and a second electric machine mechanically coupled with a second spool of the gas turbine engine. The system also includes a first AC bus and a second AC bus. A first electrical channel electrically couples the first electric machine to the first AC bus and a second electrical channel electrically couples the second electric machine to the second AC bus. The system also includes one or more connection links and one or more power converters for selectively electrically coupling the first and second electrical channels so that electrical power generated by one electric machine can be converted and shared with the other electric machine and electrical loads of the other channel.

Abstract: A power system including a power converter system and an electric machine is provided. In one aspect, the power converter system has first and second switching elements. The electric machine includes a first multiphase winding electrically coupled with the first switching elements and a second multiphase winding electrically coupled with the second switching elements. The first and second multiphase windings are arranged and configured to operate electrically opposite in phase with respect to one another. One or more processors control the first switching elements to generate first pulse width modulated (PWM) signals based on received voltage commands to render a first common mode signal and also control the second switching elements to generate second PWM signals based on received voltage commands to render a second common mode signal. The rendered first and second common mode signals have the same or similar waveform with opposite polarity with respect to one another.

Abstract: An AC electrical system for a vehicle and methods of operating the same are provided. In one aspect, an AC electrical system includes a first electric machine mechanically coupled with a first spool of a gas turbine engine and a second electric machine mechanically coupled with a second spool of the gas turbine engine. The system also includes a first AC bus and a second AC bus. A first electrical channel electrically couples the first electric machine to the first AC bus and a second electrical channel electrically couples the second electric machine to the second AC bus. The system also includes one or more connection links and one or more power converters for selectively electrically coupling the first and second electrical channels so that electrical power generated by one electric machine can be converted and shared with the other electric machine and electrical loads of the other channel.

Abstract: A power converter assembly includes a housing, a cold plate in the housing, and a set of power converter components on the cold plate. The cold plate is configured to receive a coolant. A first medium in the housing surrounds the cold plate and components. An expandable heat transfer structure is attached to one of the cold plate and the housing.

Abstract: A DC charging circuit for an electric vehicle includes a neutral-point clamped (NPC) rectifier and a DC/DC buck converter. The NPC rectifier is configured to convert three-phase AC power to a first DC voltage at a rectifier output stage. The DC/DC buck converter includes a first DC stage coupled to the rectifier output stage, and a second DC stage configured to be coupled to the electric vehicle. The DC/DC buck converter is configured to convert the first DC voltage to a second DC voltage to be supplied to the electric vehicle.

Abstract: An electric power system for a vehicle includes at least one electric machine, one or more power rectifiers, and a plurality of DC channels. The at least one electric machine includes a plurality of tooth-wound multi-phase windings that are substantially magnetically decoupled, and the at least one electric machine is mechanically balanced even if one of the plurality of windings is de-energized. The one or more power rectifiers are configured to produce rectified power from the power generated by the at least one electric machine. The plurality of DC channels are formed after the at least one power rectifier and are configured to provide DC power to one or more loads within a vehicle.

Abstract: Systems and methods are provided for a soft switching topology for a direct current (DC)-DC converter. The systems and methods determine an operational status of an electric motor, and activate at least one of an upper or lower first or second semiconductor switches based on an operation of the electric motor. The first and second switching circuits are conductively coupled to a power inverter circuit. The systems and methods include deliver an adjusted voltage to one of the power inverter circuit or a power circuit based on the operational status of the electric motor.

Abstract: A power system including a power converter system and an electric machine is provided. In one aspect, the power converter system has first and second switching elements. The electric machine includes a first multiphase winding electrically coupled with the first switching elements and a second multiphase winding electrically coupled with the second switching elements. The first and second multiphase windings are arranged and configured to operate electrically opposite in phase with respect to one another. One or more processors control the first switching elements to generate first pulse width modulated (PWM) signals based on received voltage commands to render a first common mode signal and also control the second switching elements to generate second PWM signals based on received voltage commands to render a second common mode signal. The rendered first and second common mode signals have the same or similar waveform with opposite polarity with respect to one another.

Abstract: A method and system for operating a hybrid propulsion system, includes controllably providing a first power to a first bus and a first inverter, electrically coupling a first motor with a second inverter by way of a second bus, operably converting, by the second inverter, the first power received by the first inverter to a starting power adapted for starting the first motor, and increasing, by the second inverter, the starting power to match the first power received.

Abstract: A power source for an aircraft having an engine, the power source including: a fuel cell assembly configured to be integrated into the engine, the fuel cell assembly including: a first fuel cell group; and a second fuel cell group, wherein during a first operating condition of the power source the fuel cell assembly is configured to provide a first power output from the first fuel cell group and the second fuel cell group and during a second operating condition is further configured to provide a second power output from the first fuel cell group, the second power output being different than the first power output.

Abstract: An aircraft electrical system including: a first DC power bus and a fuel cell assembly including a first fuel cell group, wherein the first fuel cell group is electrically coupled directly to the first DC power bus without a voltage converter to provide a first power output to the first DC power bus.

Abstract: A power source for an aircraft having a gas turbine engine, including: an electrical connection assembly; a fuel cell assembly integrated into the gas turbine engine, electrically coupled to the connection assembly and configured to provide a first power output; and an electric machine coupled to the gas turbine engine, electrically coupled to the connection assembly and configured to provide a second power output, wherein both the first power output from the fuel cell assembly and the second power output from the electric machine are provided to the connection assembly during operating of the gas turbine engine and wherein the connection assembly is electrically coupled to an aircraft electrical load.

Abstract: The present disclosure relates to electrical machines (100, 200) configured to be fed by pulse width modulation from a power converter (170) and comprising a stator (110), a rotor (120), a rotor shaft (130) and one or more bearings (140, 141) arranged between the rotor (120) and the stator (110). The electrical machine (100, 200) further comprising an electrical shunt (160, 161) arranged between the rotor shaft (130) and the stator (110). The present disclosure also relates to methods (500) to mitigate electrical discharge machining bearing currents in electrical machines (100, 200).

Abstract: Systems and methods of aircraft thrust management are provided. For example, a propulsion system for an aircraft comprises a fuel cell assembly comprising a fuel cell, a turbomachine, and a controller comprising memory and one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the propulsion system to perform operations including receiving data indicative of a propulsion system thrust discrepancy and modifying an output of the fuel cell in response to receiving data indicative of the propulsion system thrust discrepancy. Modifying the fuel cell output may include modifying output products, an electrical power output, or both of the fuel cell to balance the thrust provided by the propulsion system.

Abstract: A system includes a starter generator configured to provide power to a first bus and a first inverter, a second inverter coupled to the first inverter, a first switch configured to selectively couple the second inverter to the first bus and to a second bus, a second switch configured to selectively couple a first motor to the first bus and to the second bus, and a controller. The controller sets the first switch to a second position and the second switch to a second position, causes the second inverter to convert the power from the first inverter to a starting power for starting the first motor, causes the second inverter to increase the starting power to match the power provided to the first bus from the starter generator, and switches the second switch to the first position, when the starting power matches the power from the starter generator.

Abstract: A power system including a power converter system and an electric machine is provided. In one aspect, the power converter system has first and second switching elements. The electric machine includes a first multiphase winding electrically coupled with the first switching elements and a second multiphase winding electrically coupled with the second switching elements. The first and second multiphase windings are arranged and configured to operate electrically opposite in phase with respect to one another. One or more processors control the first switching elements to generate first pulse width modulated (PWM) signals based on received voltage commands to render a first common mode signal and also control the second switching elements to generate second PWM signals based on received voltage commands to render a second common mode signal. The rendered first and second common mode signals have the same or similar waveform with opposite polarity with respect to one another.

Abstract: A system includes a starter generator configured to provide power to a first bus and a first inverter, a second inverter coupled to the first inverter, a first switch configured to selectively couple the second inverter to the first bus and to a second bus, a second switch configured to selectively couple a first motor to the first bus and to the second bus, and a controller. The controller sets the first switch to a second position and the second switch to a second position, causes the second inverter to convert the power from the first inverter to a starting power for starting the first motor, causes the second inverter to increase the starting power to match the power provided to the first bus from the starter generator, and switches the second switch to the first position, when the starting power matches the power from the starter generator.

Abstract: A method for preventing damage in a bearing of a generator of an electrical power system includes monitoring one or more electrical signals of a power conversion assembly of the electrical power system. The method also includes estimating an impedance path of common mode current from a terminal to ground using the operating parameter(s) of the power conversion assembly. Further, the method includes determining a one or more magnitudes and/or a one or more phase angles of the impedance path at different frequencies, such a switching frequency and/or harmonics. Moreover, the method includes determining whether the impedance path is indicative of degradation in at least one of bearing insulation or a ground brush of the generator based on a change in the one or more magnitudes and/or the one or more phase angles. In addition, the method includes implementing a control action when the impedance path is indicative of degradation in the bearing insulation and/or the ground brush of the generator.

Abstract: An AC electrical system for a vehicle and methods of operating the same are provided. In one aspect, an AC electrical system includes a first electric machine mechanically coupled with a first spool of a gas turbine engine and a second electric machine mechanically coupled with a second spool of the gas turbine engine. The system also includes a first AC bus and a second AC bus. A first electrical channel electrically couples the first electric machine to the first AC bus and a second electrical channel electrically couples the second electric machine to the second AC bus. The system also includes one or more connection links and one or more power converters for selectively electrically coupling the first and second electrical channels so that electrical power generated by one electric machine can be converted and shared with the other electric machine and electrical loads of the other channel.