Multiple coil electric generator in turbine engine

1. A turbine engine comprising:

a drive shaft;

a first gearbox;

a second gearbox; and

an electric generator comprising:

a first rotating element comprising a first magnet array and mechanically coupled to the drive shaft by at least the first gearbox;

a second rotating element comprising a second magnet array and mechanically coupled to the drive shaft by at least the second gearbox, wherein a distance from the first rotating element to the drive shaft is longer than a distance from the second rotating element to the drive shaft; and

an armature comprising a first coil array and a second coil array, wherein the first gearbox is configured to cause the first rotating element to rotate at a first angular velocity and at a tangential velocity relative to the first coil array, and wherein the second gearbox is configured to cause the second rotating element to rotate at a second angular velocity and at the tangential velocity relative to the second coil array, the first angular velocity being different than the second angular velocity.

2. The turbine engine of claim 1 , wherein:

the first coil array is configured to produce a first alternating-current (AC) electrical current having a particular frequency and a particular phase; and

the second coil array is configured to produce a second AC electrical current having the particular frequency and the particular phase of the first AC electrical current.

3. The turbine engine of claim 1 , wherein a first tangential width of each magnetic element of the first magnet array is equal to a second tangential width of each magnetic element of the second magnet array.

4. The turbine engine of claim 1 , wherein a first tangential width of each coil element of the first coil array is equal to a second tangential width of each coil element of the second coil array.

5. The turbine engine of claim 1 , wherein:

the first coil array is positioned adjacent to the first magnet array;

the second coil array is positioned adjacent to the second magnet array;

a quantity of magnetic elements in the first magnet array is equal to a quantity of coil elements in the first coil array; and

a quantity of magnetic elements in the second magnet array is equal to a quantity of coil elements in the second coil array.

6. The turbine engine of claim 5 , wherein:

the first angular velocity is slower than the second angular velocity; and

the quantity of magnetic elements in the first rotating element is more than the quantity of magnetic elements in the second rotating element.

7. The turbine engine of claim 1 , wherein each magnetic element of the first magnet array is configured to pass over a respective coil element of the first coil array concurrently with each magnetic element of the second magnet array passing over a respective coil element of the second coil array.

8. The turbine engine of claim 1 , wherein each magnetic element of the first magnet array is configured to pass over a respective coil element of the first coil array at a rate that is equal to a rate at which each magnetic element of the second magnet array passes over a respective coil element of the second coil array.

9. The turbine engine of claim 1 , wherein each magnetic element of the magnetic elements in the first magnet array and each magnetic element of the magnetic elements in the second magnet array is configured to pass over a respective coil element in the first coil array or in the second coil array with equal frequency.

10. A method comprising:

receiving, at a first rotating element of an electric generator of a turbine engine, via a first gearbox coupled to a drive shaft of the turbine engine, first mechanical power to cause the first rotating element to rotate at a first angular velocity and at a tangential velocity relative to a first coil array of the electric generator;

receiving, at a second rotating element of the electric generator, via a second gearbox coupled to the drive shaft, second mechanical power to cause the second rotating element to rotate at a second angular velocity and at the tangential velocity relative to a second coil array of the electric generator, the first angular velocity being different than the second angular velocity, wherein a distance from the first rotating element to the drive shaft is longer than a distance from the second rotating element to the drive shaft;

generating, at the first coil array and based on the first mechanical power, first electrical current;

generating, at the second coil array and based on the second mechanical power, second electrical current; and

outputting, by an electrical output element of the electric generator, to an electrical load, the first electrical current and the second electrical current.

11. The method of claim 10 , wherein:

generating the first electrical current comprises generating a first alternating-current (AC) electrical current having a particular frequency and a particular phase; and

generating the second electrical current comprises generating a second AC electrical current having the particular frequency and the particular phase of the first AC electrical current.

12. The method of claim 10 , wherein a first tangential width of a first magnetic element of a first magnet array of the first rotating element is equal to a second tangential width of a second magnetic element of a second magnet array of the second rotating element.

13. The method of claim 10 , wherein a first tangential width of a first coil element of the first coil array is equal to a second tangential width of a second coil element of the second coil array.

14. The method of claim 10 , wherein:

a quantity of magnetic elements in a first magnet array of the first rotating element is equal to a quantity of coil elements in the first coil array; and

a quantity of magnetic elements in a second magnet array of the second rotating element is equal to a quantity of coil elements in the second coil array.

15. The method of claim 10 , wherein:

the first angular velocity is slower than the second angular velocity; and

a quantity of magnetic elements in the first rotating element is more than a quantity of magnetic elements in the second rotating element.

16. A turbine engine comprising:

a drive shaft;

a first gearbox;

a second gearbox; and

an electric generator comprising:

a first rotating element comprising a first magnet array and mechanically coupled to the drive shaft by at least the first gearbox;

a second rotating element comprising a second magnet array and mechanically coupled to the drive shaft by at least the second gearbox, wherein a distance from the first rotating element to the drive shaft is longer than a distance from the second rotating element to the drive shaft; and

an armature comprising a first coil array and a second coil array,

wherein the first coil array is configured to produce a first alternating-current (AC) electrical current having a particular frequency and a particular phase,

the second coil array is configured to produce a second AC electrical current having the particular frequency and the particular phase of the first AC electrical current,

wherein each magnetic element of the first magnet array is configured to pass over a respective coil element of the first coil array concurrently with each magnetic element of the second magnet array passing over a respective coil element of the second coil array,

wherein the first gearbox is configured to cause the first rotating element to rotate at a first angular velocity and at a tangential velocity relative to the first coil array, and

wherein the second gearbox is configured to cause the second rotating element to rotate at a second angular velocity and at the tangential velocity relative to the second coil array, the first angular velocity being different than the second angular velocity.

17. The turbine engine of claim 16 , wherein a first tangential width of each magnetic element of the first magnet array is equal to a second tangential width of each magnetic element of the second magnet array.

18. The turbine engine of claim 16 , wherein a first tangential width of each coil element of the first coil array is equal to a second tangential width of each coil element of the second coil array.

19. The turbine engine of claim 16 ,

wherein the first coil array is positioned adjacent to the first magnet array,

wherein the second coil array is positioned adjacent to the second magnet array,

wherein a quantity of magnetic elements in the first magnet array is equal to a quantity of coil elements in the first coil array, and

wherein a quantity of magnetic elements in the second magnet array is equal to a quantity of coil elements in the second coil array.

20. The turbine engine of claim 19 ,

wherein the first angular velocity is slower than the second angular velocity, and

wherein the quantity of magnetic elements in the first rotating element is more than the quantity of magnetic elements in the second rotating element.