Aircraft with electric motor and rechargeable power source

Patent metadata

Field	Value
Publication number	US-11267574-B2
Application number	US-201314064366-A
Country	US
Kind code	B2
Filing date	Oct 28, 2013
Priority date	Oct 28, 2013
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

A method and apparatus for controlling an electric aircraft. An apparatus comprises a motor, a power source, and a four-quadrant controller. The motor operates in four quadrants of operational space and operates in one of an accelerating state and a regenerative braking state. A total current flows through the motor. The power source is connected to the motor, and when the motor operates in the regenerative braking state, the total current flows through the power source. The power source has a maximum allowable current. The four-quadrant controller is programmed to identify a recharging parameter, brake the motor to initiate the regenerative braking state when the recharging parameter is present, recharge the power source with the total current during the regenerative braking state, and control a duty cycle of the motor such that the total current does not exceed the maximum allowable current during the regenerative braking state.

First claim

What is claimed is:

1. An aircraft that comprises:
multiple electric motor assemblies connected to a plurality of propellers;
a source of electric power connected to and configured to power each of the multiple electric motor assemblies, such that each electric motor assembly of the multiple electric motor assemblies is configured to parasitically charge the source of electric power and respectively comprises:
an operating state and a recharge state;
a power inverter that comprises only one inductor within the power inverter;
a motor connected to the power inverter; and
a voltage controller that comprises:
a first pair of switches connected to the source of electric power;
a second pair of switches connected to the source of electric power;
a single diode connected to the inductor within the power inverter;
only one inductor within the voltage controller located between and connected to the first pair of switches and the second pair of switches and configured to store energy;
a switch, distinct from the first pair of switches and the second pair of switches, connected to the inductor within the power inverter and configured to:
direct current from the voltage controller to the power inverter responsive to the electric motor assembly being in the operating state and the switch connected to the inductor within the voltage controller being closed; and
direct current through the inductor within the voltage controller to the source of electric power responsive to the electric motor assembly being in the recharge state and the switch connected to the inductor within the voltage controller being open;

only one capacitor that comprises a first terminal and a second terminal, the capacitor being configured to:
receive an energy from the one inductor within the voltage controller;
maintain a desired voltage;
limit a voltage output from the voltage controller that recharges the source of electric power; and
drive the power inverter;

the first terminal of the one capacitor connected to:
the single diode; and
a first switch of the first pair of switches; and

the second terminal of the one capacitor connected to:
a first switch of the second pair of switches; and
a series of switches within the power inverter.

2. The aircraft of claim 1 , further comprising:
a controller programmed to:
control the voltage controller and the power inverter in each electric motor assembly; and
identify a recharging parameter selected from one of a total current or a voltage for each motor; and wherein:
the one capacitor is configured to maintain the desired voltage and drive the power inverter with a current based upon a duty cycle of the first pair of switches and the second pair of switches to power each motor; and
the voltage controller is programmed to receive a commanded current from a commanded current calculator.

3. The aircraft of claim 1 , further comprising a controller programmed to identify a recharging parameter comprising a current from each motor.

4. The aircraft of claim 1 , further comprising:
the source of electric power being a battery;
a battery balancer circuit configured to monitor a battery charge state of the battery; and
a controller programmed to, respectively for each of the multiple electric motor assemblies:
open or close the switch connected to the inductor within the power inverter and the capacitor in the voltage controller and thereby change, based upon a charge state received from the battery, each electric motor assembly between the operating state and the recharge state;
control a duty cycle for each switch in the first pair of switches connected to the battery and the second pair of switches within the voltage controller and thereby control current to the capacitor in the voltage controller;
change a direction of a torque of each electric motor assembly; and
calculate a command current for each electric motor assembly based upon:
a commanded current from the battery balancer circuit;
a commanded voltage from the battery balancer circuit;
an average duty cycle of each electric motor assembly; and
an actual current output of each electric motor assembly.

5. The aircraft of claim 4 , further comprising:
each motor configured to turn a corresponding one of the plurality of propellers;
the battery balancer circuit configured to use the battery charge state to determine a total commanded current for the multiple electric motor assemblies, wherein the total commanded current is determined by current needs of the battery;
a commanded current calculator programmed to determine a commanded current for each electric motor assembly in the multiple electric motor assemblies from the total commanded current, wherein the commanded current for each electric motor assembly in the multiple electric motor assemblies is proportional to a measured current of each electric motor assembly; and
a controller connected to each electric motor assembly and programmed to control the first pair of switches and the second pair of switches in each electric motor in the multiple electric motor assemblies based upon the commanded current for each electric motor assembly to control a current provided from each electric motor assembly in the recharge state to the commanded current for each electric motor assembly.

6. The aircraft of claim 5 , wherein the commanded current calculator is programmed to:
receive a measured current for each electric motor assembly in the multiple electric motor assemblies;
receive an average duty cycle for each electric motor assembly in the multiple electric motor assemblies;
determine an effective current for each electric motor assembly in the multiple electric motor assemblies based upon a quotient of the measured current for each motor divided by the average duty cycle for each motor;
determine a total effective current based upon a sum of the effective current for each electric motor assembly in the multiple electric motor assemblies; and
determine the commanded current for each electric motor assembly in the multiple electric motor assemblies based upon a quotient of the effective current for each motor divided by the total effective current and multiplied by the total commanded current.

7. The aircraft of claim 1 , wherein the aircraft is selected from one of:
an airplane;
a helicopter;
a rotorcraft;
a quadcopter; and
an unmanned aerial vehicle.

8. An aircraft that comprises:
a battery;
multiple electric motor assemblies connected to multiple propellers, each electric motor assembly of the multiple electric motor assemblies, respectively, comprises:
a voltage controller programmed to receive a commanded current from a commanded current calculator;
an operating state and a recharge state;
a power inverter that comprises only one inductor within the power inverter;
a motor connected to a propeller of the multiple propellers;
wherein the voltage controller comprises:
a first pair of switches connected to the battery;
a second pair of switches connected to battery;
a single diode connected to the inductor within the power inverter;
only one inductor within the voltage controller located between and connected to the first pair of switches and the second pair of switches and configured to store energy;
a switch, distinct from the first pair of switches and the second pair of switches, connected to the inductor within the power inverter and configured to:
direct current from the voltage controller to the power inverter responsive to the electric motor assembly being in the operating state and the switch connected to the inductor within the voltage controller being closed; and

direct current through the inductor within the voltage controller to th

Assignees

• Boeing Co

Inventors

• Benson Christopher Pete
• Quadracci Leonard J
• Cameron Douglas C

Classifications

• B60L53/00 Primary

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• B64U2201/20

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• B64U2101/31

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• B64U10/13

  Flying platforms · CPC title

• B64U50/34

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