Starting methods for hybrid-electric aircraft

Patent metadata

Field	Value
Publication number	US-2022135240-A1
Application number	US-202017085006-A
Country	US
Kind code	A1
Filing date	Oct 30, 2020
Priority date	Oct 30, 2020
Publication date	May 5, 2022
Grant date	—

Abstract

A method includes using an electric motor to start a thermal engine. The electric motor and thermal engine are connected to one another as the electric motor and the thermal engine of a hybrid-electric power plant in an aircraft. The electric motor can be connected to a combining gear box. The thermal engine can be connected to the combining gear box so that the electric motor and the thermal engine can provide torque to the combining gear box in a parallel hybrid-electric configuration. The combining gearbox can output torque to an air mover for providing thrust to the aircraft.

First claim

What is claimed is:

1 . A method comprising:
using an electric motor to start a thermal engine, wherein the electric motor and thermal engine are connected to one another as the electric motor and the thermal engine of a hybrid-electric power plant in an aircraft.

2 . The method as recited in claim 1 , wherein the electric motor is connected to a combining gear box, wherein the thermal engine is connected to the combining gear box so that the electric motor and the thermal engine can provide torque to the combining gear box in a parallel hybrid-electric configuration.

3 . The method as recited in claim 2 , wherein the combining gearbox outputs torque to an air mover for providing thrust to the aircraft.

4 . The method as recited in claim 3 , wherein using the electric motor to start the thermal engine includes providing torque from the electric motor to the combining gear box, and providing the torque from the combining gear box to the thermal engine to drive rotation in the thermal engine starting from a state of rest to reach a compression ratio where combustion can be initiated in the thermal engine.

5 . The method as recited in claim 1 , further comprising, after using the electric motor to start the thermal engine:
powering the aircraft with the hybrid-electric power plant with combined power from the electric motor and the thermal engine through take-off; and powering the aircraft with the hybrid-electric power plant with combined power from the electric motor and the thermal engine while climbing to cruise altitude.

6 . The method as recited in claim 5 , further comprising powering the aircraft with the the hybrid-electric power plant with power exclusively from the thermal engine after reaching cruise altitude.

7 . The method as recited in claim 1 , further comprising:
issuing a command from an engine control unit (ECU) to an electrical system coupled to the electric motor to bring the thermal engine to a given start speed.

8 . The method as recited in claim 7 , wherein bringing the thermal engine to a given start speed includes using engine speed feedback to the ECU.

9 . The method as recited in claim 7 , wherein the ECU commands the electric motor to decrease torque after the given start speed is reached.

10 . The method as recited in claim 1 , further comprising flying the aircraft through a mission of take-off, climb, cruise, and landing without using the electric motor as a generator.

11 . The method as recited in claim 1 , further comprising using the electric motor as a generator.

12 . A system comprising:
an electric motor; a thermal engine connected to the electric motor as a hybrid-electric power plant in an aircraft; and an engine control unit (ECU) connected to use the electric motor to start the thermal engine.

13 . The system as recited in claim 12 , wherein the electric motor is connected to a combining gear box, wherein the thermal engine is connected to the combining gear box so that the electric motor and the thermal engine can provide torque to the combining gear box in a parallel hybrid-electric configuration, wherein the electric motor and the thermal engine have horse power ratings within one order of magnitude of each other.

14 . The system as recited in claim 13 , wherein the combining gearbox is connected to an air mover for providing thrust to the aircraft.

15 . The system as recited in claim 12 , further comprising:
an electrical system coupled to the electric motor to bring the thermal engine to a given start speed.

16 . The system as recited in claim 15 , further comprising a feedback loop connected to use engine speed feedback to the ECU to bring the thermal engine to the given start speed.

Assignees

• Pratt & Whitney Canada

Inventors

• Imel Paul C
• Bergeron Sebastien
• Plamondon Etienne
• Gosselin-Brisson Samuel
• Guerchkovitch Leonid

Classifications

• B64D35/025

  of parallel type · CPC title

• B64D35/023

  of series-parallel type · CPC title

• B64D31/18

  for hybrid-electric power plants · CPC title

• B64D27/33

  Hybrid electric aircraft · CPC title

• B64D31/14 Primary

  Transmitting means between initiating means and power plants · CPC title