Self adjusting generator speed control

1. A generator control system comprising:

a generator;

a variable displacement pump that drives a motor;

the motor that drives the generator;

a generator speed sensor that monitors the speed of the generator and generates a measurement output signal that corresponds to the speed of the generator;

a generator speed controller that receives the measurement output signal from the generator speed sensor and generates a control signal that controls the displacement of the variable displacement pump, wherein:

the generator speed controller repeatedly determines whether or not a commanded change in the load on the engine, a commanded change in the speed of the engine, or a commanded change in the load of the generator has occurred and applies default commanded event control gain values to the control signal upon an affirmative determination of an occurrence of the commanded change in the load on the engine, the commanded change in the speed of the engine, or the commanded change in the load of the generator and applies uncommanded event control gain values to the control signal upon a negative determination of an occurrence of the commanded change in the load on the engine, the commanded change in the speed of the engine, and the commanded change in the load of the generator; and

the generator speed controller compares a magnitude of generator speed surging that results from applying the uncommanded event control gain values to a threshold value and reduces the uncommanded event control gain values as needed until either the magnitude of generator speed surging is less than the threshold value or until a minimum uncommanded event control gain value threshold is reached, whichever comes first.

2. The control system according to claim 1 , wherein each reduction to the uncommanded event control gain values involves reducing the previous iteration control gain value by 10% until the magnitude of generator speed surging is less than the threshold value or until a minimum uncommanded event control gain value threshold is reached.

3. The control system according to claim 1 , wherein the magnitude of generator speed surging is calculated as the average value of the absolute value of the difference between measured generator speed and a target generator speed over a time period.

4. The control system according to claim 1 , wherein the magnitude of generator speed surging is calculated as the average value of the absolute value of the difference between measured generator speed and a target generator speed over a time period substantially equal to two periods of a waveform representing generator speed fluctuation.

5. The control system according to claim 1 , wherein the threshold value is greater than or equal to about 6 RPMs and less than or equal to about 9 RPMs.

6. A method for controlling speed surging in a generator driven by a variable displacement pump, comprising the steps of:

using a generator speed sensor to monitor the speed of the generator and generate a measurement output signal that corresponds to the speed of the generator;

using a generator speed controller to receive the measurement output signal from the generator speed sensor and generate a control signal that controls the displacement of the variable displacement pump;

using the generator speed controller to repeatedly determine whether or not a commanded change in the load on the engine, a commanded change in the speed of the engine, or a commanded change in the load of the generator has occurred and apply default commanded event control gain values to the control signal upon an affirmative determination of an occurrence of the commanded change in the load on the engine, the commanded change in the speed of the engine, or the commanded change in the load of the generator and apply uncommanded event control gain values to the control signal upon a negative determination of an occurrence of the commanded change in the load on the engine, the commanded change in the speed of the engine, and the commanded change in the load of the generator; and

using the generator speed controller to compare a magnitude of generator speed surging that results from applying the uncommanded event control gain values to the control signal to a threshold value and to reduce the uncommanded event control gain values as needed until either a magnitude of generator speed surging is less than the threshold value or until a minimum uncommanded event control gain value threshold is reached, whichever comes first.

7. The method for controlling speed surging in a generator according to claim 6 , wherein each reduction to the uncommanded event control gain values involves reducing the previous uncommanded event control gain values by 10% until the magnitude of generator speed surging is less than the threshold value or until a minimum uncommanded event control gain value threshold is reached.

8. The method for controlling speed surging in a generator according to claim 6 , wherein the magnitude of generator speed surging is calculated as the average value of the absolute value of the difference between measured generator speed and a target generator speed over a time period.

9. The method for controlling speed surging in a generator according to claim 6 , wherein the magnitude of generator speed surging is calculated as the average value of the absolute value of the difference between measured generator speed and a target generator speed over a time period substantially equal to two periods of a waveform representing generator speed fluctuation.

10. The method for controlling speed surging in a generator according to claim 6 , wherein the threshold value is greater than or equal to about 6 RPMs and less than or equal to about 9 RPMs.