Stabilization of Multimachine Power Systems by Decentralized Feedback Control

1. Stabilization of Multimachine Power Systems by Decentralized Feedback Control Zhi-Cheng Huang Department of Communications, Navigation and Control Engineering National Taiwan Ocean University

2. Outline • Introduction • Decentralized controller design • Illustrative example • Conclusions

3. Introduction • State-dependent impulse disturbance will be investigated • Direct feedback linearization compensator will be proposed • Boundedness of the system states will be guaranteed within the derived impulse intervals

4. Decentralizedcontrollerdesign • n synchronous machines • Mechanical equations

5. Decentralizedcontrollerdesign Salient-pole synchronous generator • Generator electrical dynamics

6. Decentralizedcontrollerdesign • Electrical equations

7. Decentralizedcontrollerdesign • The compensated multimachine power system model where

8. Decentralizedcontrollerdesign • DFL compensating law where except for the point (which is not in the normal working region for a generator)

9. Decentralizedcontrollerdesign • Generalizeduncertain DFL compensated model where known real constant matrices and controllable real time-varying parameter uncertainties interaction terms unknown nonlinearity constant with values either 1 or 0

10. Decentralizedcontrollerdesign • Assumption 1. (System Matrix Uncertainties) with Lebesgue measurable element

11. Decentralizedcontrollerdesign • Assumption 2.(Interaction functions) with Lebesgue measurable element

12. Decentralizedcontrollerdesign • Assumption 3. (impulse disturbance) where the effect of state changing with 12

13. An Illustrative Example A three-machine example system is chosen to demonstrate the effectiveness of the proposed nonlinear decentralized controller

14. An Illustrative Example • The excitation control input limitations • The generator #3 is an infinite bus and use the generator as the reference

15. System parameters An Illustrative Example

16. An Illustrative Example A three-machine power system

17. An Illustrative Example • The DFL compensated model for the generators #1 and #2

18. An Illustrative Example • with

19. An Illustrative Example • Assume

20. An Illustrative Example • the DFL compensated power system model will be globally asymptotically stable by the linear local state feedback

21. An Illustrative Example

22. An Illustrative Example Fig. 1. The state responses with finite number of impulse disturbances

23. An Illustrative Example

24. An Illustrative Example

25. Conclusions • The problem of decentralized control of multimachine power systems with state-jump disturbances has been explored • A new synthesis algorithm for the direct feedback linearization compensator has been proposed • Sufficient conditions have been derived such that the decentralized practical stability can be guaranteed • The states of the uncertain multimachine power systems with equidistant or periodic impulse disturbance will attract into a bounded ball

26. Q&A

27. The End Thanks for your Attention