Power system stabilization

1. A method of damping power system oscillations comprising:

obtaining an AC measurement signal from a power system location;

determining oscillation frequency values in the AC measurement signal;

extracting a plurality of single signal components from the AC measurement signal by subtracting a plurality of processed measurement signals from the AC measurement signal,

wherein each of the plurality of processed measurement signals are generated by time delaying the AC measurement signal with a time delay associated with each of the oscillation frequency values other than the oscillation frequency value of the single signal component to be extracted; and

generating a damping signal based on the plurality of single signal components.

2. The method of claim 1 , wherein obtaining the AC measurement signal comprises removing a DC bias from a measurement signal.

3. The method of claim 2 , wherein removing the DC bias from the measurement signal comprises subtracting a time delayed measurement signal with a time delay of one sampling period from the measurement signal and multiplying a resultant difference with a first gain value.

4. The method of claim 3 , wherein the first gain value is dependent on a damping ratio and the oscillation frequency value of the respective single signal component that is being extracted.

5. The method of claim 1 , wherein generating the damping signal comprises phase shifting the plurality of single signal components to phase lock them with the AC measurement signal.

6. The method of claim 5 , wherein phase shifting the plurality of single signal components comprises transforming the plurality of single signal components into a plurality of d-q domain quantities with a phase angle associated with the oscillation frequency value of the respective single signal component.

7. The method of claim 6 , wherein phase shifting the plurality of single signal components further comprises inverse transforming the plurality of d-q domain quantities into a phase shifted signal with an angle dependent on the phase angle and a phase shift angle.

8. The method of claim 7 , wherein the phase shift angle is dependent on the oscillation frequency value and damping ratio of the respective single signal component.

9. The method of claim 5 , wherein the plurality of single signal components are multiplied by a third gain value before phase shifting.

10. The method of claim 9 , wherein the third gain value is dependent on damping ratios and oscillation frequency values of the plurality of single signal components.

11. The method of claim 1 , wherein generating the damping signal comprises summing the plurality of single signal components.

12. A system for damping power system oscillations comprising:

a damping device to generate a damping signal based on a control signal; and

a damping device controller to generate the control signal, the damping device controller including:

a frequency identification module for determining oscillation frequency values in an AC measurement signal;

a signal separation module to extract a plurality of single signal components from the AC measurement signal by subtracting a plurality of processed measurement signals from the AC measurement signal;

wherein each of the plurality of processed measurement signals are generated by time delaying the AC measurement signal with a time delay associated with each of the oscillation frequency values other than the oscillation frequency value of the single signal component to be extracted.

13. The system of claim 12 , wherein the damping device comprises an automatic voltage regulator or a flexible alternating current transmission device.

14. The system of claim 12 , wherein the damping device controller comprises a subtraction module to generate the AC measurement signal by subtracting a time delayed measurement signal with a time delay of one sampling period from a measurement signal to remove a DC bias from the measurement signal.

15. The system of claim 12 , wherein damping device controller further comprises a d-q transformation module to phase shift the plurality of single signal components to phase lock them with the AC measurement signal.

16. The system of claim 15 , wherein the d-q transformation module comprises a d-q conversion module for transforming the plurality of single signal components into a plurality of d-q domain quantities with a phase angle associated with the respective oscillation frequency.

17. The system of claim 15 , wherein the d-q transformation module comprises an inverse d-q conversion module for inverse transforming the plurality of d-q domain quantities into a phase shifted signal based on the phase angle and a phase shift angle.

18. The system of claim 17 , wherein the phase shift angle is dependent on the oscillation frequency value and a damping ratio of the respective single signal component.

19. The system of claim 12 , wherein the damping device controller generates the control signal by summing the plurality of single signal components.