Hybrid turbine starter for a gas turbine engine

1 . A hybrid turbine starter (HTS) for a gas turbine engine, HTS comprising:

a turbine member;

a turbine shaft coupled to the turbine member;

an electric machine having a rotor rotatable about a rotational axis, and a stator having a set of windings, the rotor being selectively coupled with the turbine shaft, the rotor defining a rotor magnetic orientation; and

a controller module configured to, after a shutdown process of the gas turbine engine:

supply, during a first timeframe, a first electrical pulse from a supply of electrical power through the set of windings to define a first stator magnetic orientation causing the rotor to align the rotor magnetic orientation with the first stator magnetic orientation; and

supply, during a second timeframe after the first time, a second electrical pulse from the supply of electrical power through the set of windings to define a second stator magnetic orientation, the second stator magnetic orientation being circumferentially offset from the rotor magnetic orientation and causing a rotational movement of the rotor about the rotational axis that aligns the rotor magnetic orientation with the second stator magnetic orientation.

2 . The HTS of claim 1 , wherein the gas turbine engine comprises an engine drive shaft with the HTS being rotationally couplable to the engine drive shaft, and the rotation of the rotor by the controller module operably rotates the engine drive shaft.

3 . The HTS of claim 2 , wherein the controller module is configured to rotate the engine drive shaft after the shutdown process of the gas turbine engine.

4 . The HTS of claim 3 , wherein the rotation of the rotor by the controller module operably rotates the engine drive shaft at a speed of greater than 0 rpm and less than or equal to 650 rpm.

5 . The HTS of claim 3 , wherein the first timeframe and the second timeframe are each a function of a temperature of the gas turbine engine.

6 . The HTS of claim 1 , wherein the controller module is configured to supply a sequence of electrical pulses from the supply of electrical power, the sequence of electrical pulses including the first electrical pulse and the second electrical pulse, with each electrical pulse of the sequence of electrical pulses being fed to the set of windings to define a respective stator magnetic orientation offset from the rotor magnetic orientation.

7 . The HTS of claim 6 , wherein each successive electrical pulse of the sequence of electrical pulses is configured to cause a rotational movement of the rotor about the rotational axis that aligns the rotor magnetic orientation with the respective stator magnetic orientation of the successive electrical pulse, the sequence of electrical pulses configured to rotate the rotor about in a common direction.

8 . The HTS of claim 1 , wherein the electric machine is a three-phase electric machine.

9 . The HTS of claim 1 , wherein the first timeframe and the second timeframe are each a non-zero amount of time.

10 . The HTS of claim 1 , wherein the controller module is configured to wait a period of time after the first timeframe before supplying the second electrical pulse to define a wait time.

11 . The HTS of claim 1 , wherein:

a torque generated by the electric machine in response to the first electrical pulse is a function of the first timeframe and a current amplitude of the first electrical pulse; and

a torque generated by the electric machine in response to the second electrical pulse is a function of the second timeframe and a current amplitude of the second electrical pulse, respectively.

12 . The HTS of claim 1 , wherein the HTS comprises a housing defining an interior, and the electric machine and the turbine member are located within the interior.

13 . The HTS of claim 1 , wherein a torque required to drive a respective portion of the gas turbine engine is a function of a current amplitude of the first electrical pulse and the second electrical pulse.

14 . The HTS of claim 1 , wherein the supply of electrical power is a supply of direct current electrical power.

15 . The HTS of claim 1 , wherein the supply of electrical power is located on an aircraft and is immediately accessible to the HTS after a shutdown process of the gas turbine engine.

16 . The HTS of claim 1 , wherein the supply of electrical power is located on a ground cart and is not immediately accessible to the HTS after a shutdown process of the gas turbine engine.

17 . A hybrid turbine starter (HTS) for a gas turbine engine, the HTS comprising:

a turbine member;

a turbine shaft coupled to the turbine member;

an electric machine having a rotor rotatable about a rotational axis, and a stator having a set of windings, the rotor being selectively coupled with the turbine shaft, the rotor defining a rotor magnetic orientation; and

a controller module configured to:

supply, during a first timeframe, a first electrical pulse from a supply of electrical power through the set of windings to define a first stator magnetic orientation causing the rotor to align the rotor magnetic orientation with the first stator magnetic orientation; and

supply, during a second timeframe after the first time, a second electrical pulse from the supply of electrical power through the set of windings to define a second stator magnetic orientation, the second stator magnetic orientation being circumferentially offset from the rotor magnetic orientation and causing a rotational movement of the rotor about the rotational axis that aligns the rotor magnetic orientation with the second stator magnetic orientation,

wherein the first timeframe and the second timeframe are each greater than 0 seconds and less than or equal to 10 seconds.

18 . A hybrid turbine starter (HTS) for a gas turbine engine, the HTS comprising:

a turbine member;

a turbine shaft coupled to the turbine member;

an electric machine having a rotor rotatable about a rotational axis, and a stator having a set of windings, the rotor being selectively coupled with the turbine shaft, the rotor defining a rotor magnetic orientation; and

a controller module configured to:

supply, during a first timeframe, a first electrical pulse from a supply of electrical power through the set of windings to define a first stator magnetic orientation causing the rotor to align the rotor magnetic orientation with the first stator magnetic orientation;

supply, during a second timeframe after the first time, a second electrical pulse from the supply of electrical power through the set of windings to define a second stator magnetic orientation, the second stator magnetic orientation being circumferentially offset from the rotor magnetic orientation and causing a rotational movement of the rotor about the rotational axis that aligns the rotor magnetic orientation with the second stator magnetic orientation; and

wait a period of time after the first timeframe before supplying the second electrical pulse to define a wait time:

wherein the wait time is greater than 0 seconds and less than or equal to 100 seconds.

19 . The HTS of claim 18 , wherein the wait time is defined as a period of time that it takes for the rotor magnetic orientation to align with the second stator magnetic orientation from the first stator magnetic orientation.