Abstract: Aspects of the disclosure generally relate to an aircraft propulsion system for an aircraft. The aircraft propulsion system can include at least an electric power source, an electric machine, and a voltage regulator. The voltage regulator regulates the electrical power provided to the electric machine from the electrical power source. The electric power source is capable of providing an AC or DC electrical output and can include a combustion engine with a generator or an electrical storage device.

Abstract: A power converter apparatus comprises a set of switching elements communicatively coupled with a set of gate drive circuits. Each gate drive circuit is configured to provide a respective drive signal to a corresponding switching element, each switching element being switchably responsive to the respective drive signal. The apparatus includes a controller module configured to control an output state of the power converter, and selectively change one of a respective gate resistance and a respective gate current of a corresponding subset of the gate drive circuits based on the output state of the power converter.

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 power converter apparatus comprises a set of switching elements communicatively coupled with a set of gate drive circuits. Each gate drive circuit is configured to provide a respective drive signal to a corresponding switching element, each switching element being switchably responsive to the respective drive signal. The apparatus includes a controller module configured to control an output state of the power converter, and selectively change one of a respective gate resistance and a respective gate current of a corresponding subset of the gate drive circuits based on the output state of the power converter.

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: 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 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: 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: 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 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 converter apparatus comprises a set of switching elements communicatively coupled with a set of gate drive circuits. Each gate drive circuit is configured to provide a respective drive signal to a corresponding switching element, each switching element being switchably responsive to the respective drive signal. The apparatus includes a controller module configured to control an output state of the power converter, and selectively change one of a respective gate resistance and a respective gate current of a corresponding subset of the gate drive circuits based on the output state of the power converter.

Abstract: Provided is a Fresnel lens and display device with such Fresnel lens, the Fresnel lens includes an entrance plane and an exit plane with multiple bump units. The bump units include a First Bump Unit, a Second Bump Unit, and a Third Bump Unit; on one side of the central axis of said lens, the First Bump Unit, Second Bump Unit and Third Bump Unit are placed successively along the radiation direction from the central axis toward the lens edge; on the other side of the central axis of said lens, the First Bump Unit, Second Bump Unit and Third Bump Unit are also placed successively along the radiation direction from the central axis toward the lens edge. The Bump Units on both sides of the central axis of the lens are symmetrical.

Abstract: A method for operating an asynchronous doubly-fed wind turbine generator connected to a power grid in a grid-forming mode to emulate a virtual synchronous machine. The doubly-fed wind turbine generator includes a line-side converter coupled to a rotor-side converter via a direct current (DC) link. The method includes receiving, via a controller, at least one reference command from an external controller. The method also includes controlling rotor flux of the doubly-fed wind turbine generator using the at least one reference command. Further, the method includes providing power droop control for the doubly-fed wind turbine generator through at least one of rotor-side reference frame rotation and d-axis flux control.

Abstract: Aspects of the disclosure generally relate to an aircraft propulsion system for an aircraft. The aircraft propulsion system can include at least an electric power source, an electric machine, a voltage regulator, and at least one propeller. The voltage regulator regulates the electrical power provided to the electric machine from the electrical power source. The electric power source is capable of providing an AC or DC electrical output and can include a combustion engine with a generator or an electrical storage device.

Abstract: A method for operating an asynchronous doubly-fed wind turbine generator connected to a power grid in a grid-forming mode to emulate a virtual synchronous machine. The doubly-fed wind turbine generator includes a line-side converter coupled to a rotor-side converter via a direct current (DC) link. The method includes receiving, via a controller, at least one reference command from an external controller. The method also includes controlling rotor flux of the doubly-fed wind turbine generator using the at least one reference command. Further, the method includes providing power droop control for the doubly-fed wind turbine generator through at least one of rotor-side reference frame rotation and d-axis flux control.

Abstract: A system including a control system is provided. The control system includes a main drive that receives power from a power source and outputs a variable frequency and a variable amplitude AC voltage. The control system also includes a controller to interface with the main drive and an electric machine. The controller receives one or more electrical signals associated with an operating condition of the electric machine from one or more sensors disposed between the electric machine and the main drive. The controller determines correction information based on the received electrical signals and based on a desired operating condition of the electric machine. The controller transmits the correction information to the main drive. The correction information corresponds to a rotor position of the electric machine or operating commands configured to implement the desired operating condition of the electric machine.

Abstract: Provided is a Fresnel lens and display device with such Fresnel lens, the Fresnel lens includes an entrance plane and an exit plane with multiple bump units. The bump units include a First Bump Unit, a Second Bump Unit, and a Third Bump Unit; on one side of the central axis of said lens, the First Bump Unit, Second Bump Unit and Third Bump Unit are placed successively along the radiation direction from the central axis toward the lens edge; on the other side of the central axis of said lens, the First Bump Unit, Second Bump Unit and Third Bump Unit are also placed successively along the radiation direction from the central axis toward the lens edge. The Bump Units on both sides of the central axis of the lens are symmetrical.

Abstract: A drive system for driving an AC electric machine includes an electric machine power converter that provides a primary current excitation vector having a magnitude and angle to drive the AC electric machine. A control system separate from or incorporated into the power converter causes the power converter to inject a carrier signal to the AC electric machine that is superimposed onto the current vector and that generates a carrier response signal that has sensitivity to magnetic alignment information of the AC electric machine at its operating point, the carrier response signal providing a measurable magnetic alignment signature of the AC electric machine. The control system causes the power converter to inject the carrier signal at an injection angle between a constant flux injection angle and a constant torque injection angle, to reduce noise and/or vibration of the AC electric machine caused by the injected carrier signal.

Abstract: A system may be provided that may include an integrated motor drive configured to couple to a motor. The integrated motor drive may include a first converter that may be configured to electrically couple with a winding assembly of the motor. The first converter may include at least first conversion circuitry configured to form a first electrical excitation waveform and second conversion circuitry coupled in parallel to the second conversion circuitry and configured to form a second electrical excitation waveform. The first converter may also include a first transformer configured to form a first summation electrical excitation waveform from the first electrical excitation waveform and the second electrical excitation waveform that drives the motor.

Abstract: A common-mode voltage cancellation (CMVC) circuit, is disclosed. The circuit includes a first set of coupled inductors, each having a primary winding defining a first polarity, and a secondary winding. The secondary windings are electrically coupled in series. Each primary winding receives a phase voltage having a common mode voltage component from a respective input line. The circuit includes a second set of coupled inductors comprising at least one primary winding and at least one secondary winding The at least one primary winding receives a second voltage from the series connected secondary windings of the first set of coupled inductors. Each at least one secondary winding is coupled in series with a respective input line such that the common mode voltage component received on input lines will be reduced at an output of the set of secondary windings.