Abstract: A method and system for an engine starter/generator is provided. The starter/generator system includes a three phase squirrel cage induction machine, a three phase inverter/converter electrically coupled to the three phase squirrel cage induction machine. The starter/generator system also includes a bidirectional DC-DC converter electrically coupled to the three phase inverter/converter, and a digital control board configured to sensorlessly determine a rotor angle from a plurality of phase currents to the induction machine during a start mode. During the start mode, logic in the digital control board configures the starter/generator system into a combination of an induction motor, a three phase DC-AC inverter, and a DC-DC boost converter, and during a generate mode, the logic in the digital control board configures the starter/generator system into a combination of an induction generator, a three phase AC-DC converter, and a DC-DC buck converter.

Abstract: A bus centering device for use in an aircraft electrical power distribution system that includes a positive bus rail, a negative bus rail, and a ground is described. The device includes a central node, a first and second switching component configured to couple the central node to the positive rail and the negative rail for a first and second predetermined duty cycle, respectively. The device includes an inductive component coupled between the central node and ground, and is configured to maintain a voltage at the central node substantially equal to ground, wherein a voltage between the positive rail and the central node is maintained substantially equal to a voltage between the negative rail and the central node. The device includes a first and second current limiting device configured to maintain a continuity of current from the inductive component when the first and second switching components are turned off.

Abstract: A starting and generating system for use with an aircraft engine includes a starter/generator and an inverter/converter/controller (ICC) coupled to the starter/generator. The starter/generator is configured to start the aircraft engine in a start mode and to generate AC power in a generate mode. The starter/generator includes an exciter and a rotational shaft. The ICC is configured to provide AC power at a first frequency the starter/generator in the start mode and to control the exciter during the generate mode such that the generate mode AC power has a second frequency, wherein the first frequency is based on a shaft speed of the shaft.

Abstract: A method is provided for using a temporary power source to transfer a power bus from a first power source to a second power source. The first power source operates at a first electrical frequency, and the second power source operates at a second electrical frequency that is different from the first electrical frequency. The method includes adjusting the output frequency of the temporary power source to match the first electrical frequency and supplying power to the power bus from the temporary power source. The method also includes disconnecting the first power source from the power bus. The method further includes adjusting the output frequency of the temporary power source to match the second electrical frequency. The method further includes coupling the second power source to the power bus.

Abstract: A method and system for an engine starter/generator is provided. The starter/generator system includes a three phase squirrel cage induction machine, a three phase inverter/converter electrically coupled to the three phase squirrel cage induction machine. The starter/generator system also includes a bidirectional DC-DC converter electrically coupled to the three phase inverter/converter, and a digital control board configured to sensorlessly determine a rotor angle from a plurality of phase currents to the induction machine during a start mode. During the start mode, logic in the digital control board configures the starter/generator system into a combination of an induction motor, a three phase DC-AC inverter, and a DC-DC boost converter, and during a generate mode, the logic in the digital control board configures the starter/generator system into a combination of an induction generator, a three phase AC-DC converter, and a DC-DC buck converter.

Abstract: An apparatus for use with a flight control actuator and method for assembling the same is provided. The apparatus includes a motor drive system and a control unit. The motor drive system includes a capacitor-based energy storage configured to store and provide energy within or proximate to the actuator. The control unit is coupled to the motor drive system and is configured to facilitate managing power within or proximate to the actuator.