Control system and method for powering a low inertia generator with a gas turbine engine and maintaining speed governing tolerance

1 . A method comprising:

receiving a generator power demand (GPD) signal for a gas generator of a gas turbine engine (GTE);

applying a smoothing filter to the GPD signal to create a smoothed GPD signal;

determining, using the smoothed GPD signal, a GPD anticipation parameter for controlling fuel flow rate to the GTE; and

outputting a fuel flow rate request to the GTE based on the GPD anticipation parameter and a power turbine speed (NPT) controlled by an NPT governing feedback loop.

2 . The method of claim 1 , further comprising transmitting the smoothed GPD signal to a generator according to a delay based on a rate of change of the smoothed GPD signal.

3 . The method of claim 1 , wherein applying the smoothing filter also applies a rate limiter to the GPD signal.

4 . The method of claim 1 , wherein determining the GPD anticipation parameter includes:

determining a moving average of the smoothed GPD signal; and

calculating an anticipated torque or an anticipated shaft horse power using the moving average.

5 . The method of claim 4 , wherein determining the GPD anticipation parameter further includes synthesizing a gas generator speed using the anticipated torque or the anticipated shaft horse power, the method further comprising:

generating a gas generator speed request based on the synthesized gas generator speed and the NPT controlled by the NPT governing feedback loop;

providing the gas generator speed request to a gas generator speed governing feedback loop, wherein the gas generator speed governing feedback loop is disposed as an inner control loop within the NPT governing feedback loop; and

generating the fuel flow rate request using the gas generator speed governing feedback loop, and based on the gas generator speed request and a gas generator speed feedback measurement provided by the GTE.

6 . The method of claim 4 , further comprising:

generating a torque request based on the anticipated torque and the NPT controlled by the NPT governing feedback loop;

providing the torque request to a torque governing feedback loop, wherein the torque governing feedback loop is disposed as an inner control loop within the NPT governing feedback loop; and

generating the fuel flow rate request using the torque governing feedback loop, and based on the torque request and a torque feedback measurement provided by the GTE.

7 . The method of claim 4 , wherein determining the GPD anticipation parameter further includes synthesizing the fuel flow rate using the anticipated torque or the anticipated shaft horse power, the method further comprising:

generating the fuel flow rate request based on the synthesized fuel flow rate and the NPT controlled by the NPT governing feedback loop.

8 . A system comprising:

at least one controller configured to:

receive a generator power demand (GPD) signal for a gas generator of a gas turbine engine (GTE);

apply a smoothing filter to the GPD signal to create a smoothed GPD signal;

determine, using the smoothed GPD signal, a GPD anticipation parameter for controlling fuel flow rate to the GTE; and

output a fuel flow rate request to the GTE based on the GPD anticipation parameter and a power turbine speed (NPT) controlled by an NPT governing feedback loop.

9 . The system of claim 8 , wherein the at least one controller is further configured to transmit the smoothed GPD signal to a generator according to a delay based on a rate of change of the smoothed GPD signal.

10 . The system of claim 8 , wherein applying the smoothing filter also applies a rate limiter to the GPD signal.

11 . The system of claim 8 , wherein, to determine the GPD anticipation parameter, the at least one controller is further configured to:

determine a moving average of the smoothed GPD signal; and

calculate an anticipated torque or an anticipated shaft horse power using the moving average.

12 . The system of claim 11 , wherein, to determine the GPD anticipation parameter, the at least one controller is further configured to synthesize a gas generator speed using the anticipated torque or the anticipated shaft horse power, and

wherein the at least one controller is further configured to:

generate a gas generator speed request based on the synthesized gas generator speed and the NPT controlled by the NPT governing feedback loop;

provide the gas generator speed request to a gas generator speed governing feedback loop, wherein the gas generator speed governing feedback loop is disposed as an inner control loop within the NPT governing feedback loop; and

generate the fuel flow rate request using the gas generator speed governing feedback loop, and based on the gas generator speed request and a gas generator speed feedback measurement provided by the GTE.

13 . The system of claim 11 , wherein the at least one controller is further configured to:

generate a torque request based on the anticipated torque and the NPT controlled by the NPT governing feedback loop;

provide the torque request to a torque governing feedback loop, wherein the torque governing feedback loop is disposed as an inner control loop within the NPT governing feedback loop; and

generate the fuel flow rate request using the torque governing feedback loop, and based on the torque request and a torque feedback measurement provided by the GTE.

14 . The system of claim 11 , wherein, to determine the GPD anticipation parameter, the at least one controller is further configured to synthesize the fuel flow rate using the anticipated torque or the anticipated shaft horse power, and

wherein the at least one controller is further configured to generate the fuel flow rate request based on the synthesized fuel flow rate and the NPT controlled by the NPT governing feedback loop.

15 . A non-transitory machine readable medium including instructions that when executed cause at least one processor to:

receive a generator power demand (GPD) signal for a gas generator of a gas turbine engine (GTE);

apply a smoothing filter to the GPD signal to create a smoothed GPD signal;

determine, using the smoothed GPD signal, a GPD anticipation parameter for controlling fuel flow rate to the GTE; and

output a fuel flow rate request to the GTE based on the GPD anticipation parameter and a power turbine speed (NPT) controlled by an NPT governing feedback loop.

16 . The non-transitory machine readable medium of claim 15 , further comprising instructions that when executed cause the at least one processor to transmit the smoothed GPD signal to a generator according to a delay based on a rate of change of the smoothed GPD signal.

17 . The non-transitory machine readable medium of claim 15 , wherein, to determine the GPD anticipation parameter, the non-transitory machine readable medium further comprises instructions that when executed cause the at least one processor to:

determine a moving average of the smoothed GPD signal; and

calculate an anticipated torque or an anticipated shaft horse power using the moving average.

18 . The non-transitory machine readable medium of claim 17 , wherein, to determine the GPD anticipation parameter, the non-transitory machine readable medium further comprises instructions that when executed cause the at least one processor to synthesize a gas generator speed using the anticipated torque or the anticipated shaft horse power, and

wherein the non-transitory machine readable medium further comprises instructions that when executed cause the at least one processor to:

generate a gas generator speed request based on the synthesized gas generator speed and the NPT controlled by the NPT governing feedback loop;

provide the gas generator speed request to a gas generator speed governing feedback loop, wherein the gas generator speed governing feedback loop is disposed as an inner control loop within the NPT governing feedback loop; and

generate the fuel flow rate request using the gas generator speed governing feedback loop, and based on the gas generator speed request and a gas generator speed feedback measurement provided by the GTE.

19 . The non-transitory machine readable medium of claim 17 , wherein the non-transitory machine readable medium further comprises instructions that when executed cause the at least one processor to:

generate a torque request based on the anticipated torque and the NPT controlled by the NPT governing feedback loop;

provide the torque request to a torque governing feedback loop, wherein the torque governing feedback loop is disposed as an inner control loop within the NPT governing feedback loop; and

generate the fuel flow rate request using the torque governing feedback loop, and based on the torque request and a torque feedback measurement provided by the GTE.

20 . The non-transitory machine readable medium of claim 17 , wherein, to determine the GPD anticipation parameter, the non-transitory machine readable medium further comprises instructions that when executed cause the at least one processor to synthesize the fuel flow rate using the anticipated torque or the anticipated shaft horse power, and

wherein the non-transitory machine readable medium further comprises instructions that when executed cause the at least one processor to generate the fuel flow rate request based on the synthesized fuel flow rate and the NPT controlled by the NPT governing feedback loop.