At least one of a plurality of generators is a first generator configured such that a relationship of a generator output voltage with respect to a generator active power output from the generator to a corresponding first AC wiring portion has a predetermined first drooping characteristic. The control device is configured to generate a drive signal for a power conversion device by deciding a target value of a first control element such that a relationship of an AC wiring portion voltage with respect to a power conversion device active power output from the power conversion device to a first AC wiring portion corresponding to a first generator has a predetermined second drooping characteristic and correcting the target value of the first control element according to a DC voltage at a DC wiring portion.

At least one of a plurality of generators is a first generator configured such that a relationship of a generator output voltage with respect to a generator active power output from the generator to a corresponding first AC wiring portion has a predetermined first drooping characteristic. The control device is configured to generate a drive signal for a power conversion device by deciding a target value of a first control element such that a relationship of an AC wiring portion voltage with respect to a power conversion device active power output from the power conversion device to a first AC wiring portion corresponding to a first generator has a predetermined second drooping characteristic and correcting the target value of the first control element according to a DC voltage at a DC wiring portion.

A method of predicting a health status of an integrated drive generator (IDG) includes determining an effective deviation across a plurality of IDG output frequencies for a given IDG operation period. The method includes correlating the effective deviation to an IDG capability to determine a health of the IDG. A system for predicting a health status of an integrated drive generator (IDG) includes an IDG and a generator control unit (GCU) operatively connected to the IDG to determine a plurality of IDG output frequencies for a given IDG operation period. The system includes a central processing unit (CPU) operatively connected to the GCU to receive the IDG output frequencies therefrom. The CPU is configured and adapted to determine an effective deviation across at least some of the plurality of IDG output frequencies for the given IDG operation period, and correlate the effective deviation to an IDG capability to determine a health of the IDG.

A system includes a first AC bus configured to supply power from a first generator. A first generator line contactor (GLC) selectively connects the first AC bus to the first generator. A second AC bus is configured to supply power from a second generator. A second GLC selectively connecting the second AC bus to the second generator. An auxiliary generator line contactor (ALC) is connected to selectively supply power to the first and second AC buses from an auxiliary generator. A first bus tie contactor (BTC) electrically connects between the first GLC and the ALC. A second BTC electrically connects between the ALC and the second GLC. A ram air turbine (RAT) automatic deployment controller is operatively connected to automatically deploy a RAT based on the combined status of the first GLC, the second GLC, the ALC, the first BTC, and the second BTC.

A brushless starter-generator system is contained within a single housing. The housing has a first end with an opening to receive a drive spline from a motive source and an opposing second end. A brushless, rotating machine is located adjacent the first end and is kinetically connectable to the drive spline. A power control unit is adjacent the second end and electrically coupled to the brushless, rotating machine. The brushless, rotating machine is selected from the group consisting of a synchronous machine, a permanent magnet machine, and an induction machine. Electrical and mechanical interfaces are identical to a like-rated brushed version for a true “drop-in” replacement capability to facilitate replacements and up-grades.

Methods and systems for operating a hybrid electric aircraft propulsion system mounted to an aircraft. The method comprises driving a first rotating propulsor from a first electric motor operatively connected to a generator, driving a second rotating propulsor from a second electric motor operatively connected to the generator, and driving a third rotating propulsor from a thermal engine, the thermal engine operatively connected to the generator and configured to drive the generator.

The disclosed embodiments aim to improve upon existing multi stage generators for providing power to a load. In particular, embodiments of the invention include a regulator situated between the output of a pilot exciter and the main exciter of a multi stage generator system, the regulator arranged to limit the voltage available to a field current control element which sets the field current supplied to the main exciter.

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.

A generator control unit includes a plurality of permanent magnet generator (PMG) inputs, a transformer including a multi-configuration input winding and at least one output winding. Each PMG input in the plurality of PMG inputs is connected to the multi-configuration input winding at a corresponding input winding input.

An auxiliary power unit (APU) control system for an aircraft is disclosed. The APU control system includes an APU, one or more processors, and a memory coupled to the one or more processors. The memory stores data comprising a database and program code that, when executed by the one or more processors, causes the APU control system to receive a one or more ambient signals indicative of an air density value and one or more power signals indicative of a specific amount of power generated by the APU. The APU control system is further caused to determine a variable rotational speed of the APU based on the air density value and instruct the APU to operate at the variable rotational speed. The APU continues to generate the specific amount of power when operating at the variable rotational speed.