Abstract: A dual-input 18-pulse autotransformer rectifier unit for more electric aircraft AC-DC converter uses an autotransformer with a nine-phase output to condition AC power prior to DC rectifying the AC power.

Abstract: Embodiments of the disclosure include an electric taxi system including a generator configured to provide an AC power source and a main controller configured to generate one or more PWM control signals. The electric taxi system also includes a plurality of motor controllers connected in parallel to the generator, wherein each of the plurality of motor controllers receives one of the one or more PWM control signals. The electric taxi system further includes a plurality of motors, wherein each of the plurality of motors are coupled to one of the plurality of motor controllers.

Abstract: Embodiments of the disclosure include an electric taxi system including a generator configured to provide an AC power source and a main controller configured to generate one or more PWM control signals. The electric taxi system also includes a plurality of motor controllers connected in parallel to the generator, wherein each of the plurality of motor controllers receives one of the one or more PWM control signals. The electric taxi system further includes a plurality of motors, wherein each of the plurality of motors are coupled to one of the plurality of motor controllers.

Abstract: A power converter system includes an interleaved power converter having a plurality of parallel-connected phase legs between DC terminals and an AC terminal. A plurality of parallel-connected inductors are each connected to one of the plurality of parallel-connected phase legs to provide a summed output of the parallel-connected phase legs to the AC terminal. A controller generates PWM signals used to control the state of each of the plurality of phase legs by comparing a carrier signal to a reference signal, wherein a period of the carrier signal is randomly varied from a nominal period.

Abstract: A multi-level power converter system includes a multi-level power converter configured to synthesize at least three direct current (DC) voltages into an alternating current (AC) output voltage, and includes a plurality of transistors. A controller generates pulse-width modulation (PWM) signals used to control a state of the plurality of transistors of the multi-level converter by comparing first and second carrier signals to a reference signals, wherein a period of the first and second carrier signals is randomly varied from a nominal period.

Abstract: A thermal stress reduction method includes ramping an electric power generator to start an aircraft engine, for a time period associated with the aircraft engine start sequence toggling a three-level inverter switch array to a three-level pulse width modulation mode, determining if a first time interval in the three-level pulse width modulation mode exceeded a predetermined three-level pulse width modulation mode interval, in response to the first time interval exceeding the three-level pulse width modulation mode interval, toggling the three-level inverter switch array to a two-level pulse width modulation mode, determining if a second time interval in the two-level pulse width modulation mode exceeded a predetermined two-level pulse width modulation mode interval and in response to the second time interval exceeding the two-level pulse width modulation mode interval, toggling the three-level inverter switch array to the three-level pulse width modulation mode.

Abstract: A thermal stress reduction method includes ramping an electric power generator to start an aircraft engine, for a time period associated with the aircraft engine start sequence toggling a three-level inverter switch array to a three-level pulse width modulation mode, determining if a first time interval in the three-level pulse width modulation mode exceeded a predetermined three-level pulse width modulation mode interval, in response to the first time interval exceeding the three-level pulse width modulation mode interval, toggling the three-level inverter switch array to a two-level pulse width modulation mode, determining if a second time interval in the two-level pulse width modulation mode exceeded a predetermined two-level pulse width modulation mode interval and in response to the second time interval exceeding the two-level pulse width modulation mode interval, toggling the three-level inverter switch array to the three-level pulse width modulation mode.

Abstract: A thermal stress reduction method includes ramping an electric power generator to start an aircraft engine, for a time period associated with the aircraft engine start sequence toggling a three-level inverter switch array to a three-level pulse width modulation mode, determining if a first time interval in the three-level pulse width modulation mode exceeded a predetermined three-level pulse width modulation mode interval, in response to the first time interval exceeding the three-level pulse width modulation mode interval, toggling the three-level inverter switch array to a two-level pulse width modulation mode, determining if a second time interval in the two-level pulse width modulation mode exceeded a predetermined two-level pulse width modulation mode interval and in response to the second time interval exceeding the two-level pulse width modulation mode interval, toggling the three-level inverter switch array to the three-level pulse width modulation mode.

Abstract: A dual-input nine-phase autotransformer converts first and second three-phase AC inputs to a nine-phase AC output. The autotransformer includes input terminals for connection to a first three-phase AC input and a second three-phase AC input smaller than the first three-phase AC input. The autotransformer includes a first plurality of coils, a second plurality, and a third plurality of coils wound on respective phase legs of the autotransformer. The autotransformer includes a plurality of output terminals for providing a plurality of AC output voltages, and a plurality of internal terminals for connecting the first, second, and third plurality of coils in a configuration that provides a 40° phase shift in the AC outputs provided by the dual-input nine-phase autotransformer.

Abstract: A system and method for operating a semi-conductor based circuit breaker as a transient current limiter includes a semi-conductor switch that operates in a linear mode during a transient event and thereby reduces the transient current passing through the switch.

Abstract: A thermal stress reduction method includes ramping an electric power generator to start an aircraft engine, for a time period associated with the aircraft engine start sequence toggling a three-level inverter switch array to a three-level pulse width modulation mode, determining if a first time interval in the three-level pulse width modulation mode exceeded a predetermined three-level pulse width modulation mode interval, in response to the first time interval exceeding the three-level pulse width modulation mode interval, toggling the three-level inverter switch array to a two-level pulse width modulation mode, determining if a second time interval in the two-level pulse width modulation mode exceeded a predetermined two-level pulse width modulation mode interval and in response to the second time interval exceeding the two-level pulse width modulation mode interval, toggling the three-level inverter switch array to the three-level pulse width modulation mode.

Abstract: A dual-input 18-pulse autotransformer rectifier unit for more electric aircraft AC-DC converter uses an autotransformer with a nine-phase output to condition AC power prior to DC rectifying the AC power.

Abstract: A dual-input nine-phase autotransformer converts first and second three-phase AC inputs to a nine-phase AC output. The autotransformer includes input terminals for connection to a first three-phase AC input and a second three-phase AC input smaller than the first three-phase AC input. The autotransformer includes a first plurality of coils, a second plurality, and a third plurality of coils wound on respective phase legs of the autotransformer. The autotransformer includes a plurality of output terminals for providing a plurality of AC output voltages, and a plurality of internal terminals for connecting the first, second, and third plurality of coils in a configuration that provides a 40° phase shift in the AC outputs provided by the dual-input nine-phase autotransformer.

Abstract: A system and method for operating a semi-conductor based circuit breaker as a transient current limiter includes a semi-conductor switch that operates in a linear mode during a transient event and thereby reduces the transient current passing through the switch.

Abstract: A control circuit for a lamp. The control circuit is used in conjunction with an alternating current (AC) variable voltage power source to energize the lamp. The control circuit includes a voltage sensing component for sensing the voltage of an voltage input signal from the power source for energizing the lamp. The control circuit includes a controller configured to estimate a delay angle as a linear function of the sensed voltage. The control circuit includes an AC converter for modifying the voltage input signal according to the estimated delay angle to generate an AC voltage output signal having a constant root mean square voltage for energizing the lamp.

Abstract: A ballast including an H-bridge type inverter for driving a lamp and a filter circuit that includes a buck inductor is disclosed. The buck inductor is a primary winding of a transformer, and a secondary winding of the transformer provides power to a controller of the ballast. The controller operates the inverter in various pre-ignition modes of operation such that prior to ignition, the open circuit voltage (OCV) (i.e., voltage across the lamp) and buck inductor current are controlled to transfer sufficient power from the primary of the transformer to the secondary winding of the transformer to power the controller. No switches of the inverter are turned on while there is a non-zero current through the filter circuit.

Abstract: A ballast including an H-bridge type inverter for driving a lamp and a filter circuit that includes a buck inductor is disclosed. The buck inductor is a primary winding of a transformer, and a secondary winding of the transformer provides power to a controller of the ballast. The controller operates the inverter in various pre-ignition modes of operation such that prior to ignition, the open circuit voltage (OCV) (i.e., voltage across the lamp) and buck inductor current are controlled to transfer sufficient power from the primary of the transformer to the secondary winding of the transformer to power the controller. No switches of the inverter are turned on while there is a non-zero current through the filter circuit.

Abstract: A control circuit for a lamp. The control circuit is used in conjunction with an alternating current (AC) variable voltage power source to energize the lamp. The control circuit includes a voltage sensing component for sensing the voltage of an voltage input signal from the power source for energizing the lamp. The control circuit includes a controller configured to estimate a delay angle as a linear function of the sensed voltage. The control circuit includes an AC converter for modifying the voltage input signal according to the estimated delay angle to generate an AC voltage output signal having a constant root mean square voltage for energizing the lamp.