Fault-tolerant power system architecture for aircraft electric propulsion

A method for fault-tolerant operation of an aircraft electric propulsor, the method comprising:

• monitoring operation of an AC motor and of a motor controller that is configured and connected to convert DC power from a DC bus into AC power for the AC motor;
• detecting a fault during monitoring;
• opening a contactor that is disposed between the DC bus and the motor controller in response to detecting the fault;
• determining a fault type of the fault;
• and
• commanding an inverter of the motor controller to a safe state mode which is dependent on the fault type.

A system comprising a DC source, a DC bus connected to receive DC power from the DC source, a motor controller connected to receive DC power from the DC bus, and an AC motor connected to receive AC power from the motor controller, wherein:

• the AC motor comprises a rotor, a stator, a first winding at a first angular position on the stator, a second winding at a second angular position on the stator different than first angular position, and a third winding at a third angular position on the stator different than first and second angular positions;
• and
• the motor controller comprises an inverter connected to receive DC power from the DC bus and to supply AC power to the first, second, and third windings, and a controller configured to perform operations comprising:
• (a) controlling first, second, and third switches in the inverter so that three phases of AC power are supplied in sequence to the first, second, and third windings during system operation;
• (b) detecting a turn-to-turn fault in one of the first, second and third windings during system operation;
• and
• (c) shorting the first, second, and third power switches together in response to detecting the turn-to-turn fault.

An aircraft comprising a DC source, a DC bus connected to receive DC power from the DC source, and an electric propulsion unit connected to receive DC power from the DC bus, wherein:

• the electric propulsion unit comprises a motor controller connected to receive DC power from the DC bus, an AC motor connected to receive AC power from the motor controller, and a propeller having a shaft which is coupled to the rotor of the AC motor operatively coupled to the AC motor;
• the AC motor comprises a rotor, a stator, a first winding at a first angular position on the stator, a second winding at a second angular position on the stator different than first angular position, and a third winding at a third angular position on the stator different than first and second angular positions;
• and
• the motor controller comprises an inverter connected to receive DC power from the DC bus and to supply AC power to the first, second, and third windings, and a controller configured to perform operations comprising:
• (a) controlling first, second, and third switches in the inverter so that three phases of AC power are supplied in sequence to the first, second, and third windings during system operation;
• (b) detecting a fault in the motor controller or an input to the motor controller during system operation;
• and
• (c) opening the first, second, and third power switches together in response to detecting the fault.