Design and Comparison of a Novel Controller Based on Control Lyapunov Function and a New Sliding Mode Controller for Robust Power Flow Control Using UPFC

Abstract

Unified power flow controller (UPFC) is a complex Flexible AC Transmission System (FACTS) device. UPFC is capable of controlling selectively the transmission line parameters in order to power flow control and power oscillation damping. This paper presents an advance to power flow control in a power system with UPFC by two nonlinear controllers; one based on the Control Lyapunov Function (CLF) (named also as Direct Lyapunov Method (DLM)) and the other is based on Sliding Mode Control. A state variable control scheme is implemented to challenge the problems of reference tracking, robustness against parameter uncertainty and rejecting external disturbances. Chattering phenomena and discontinuity of the controllers are also removed to obtain a continuous and smooth controller. The proposed controllers are robust against uncertainties and reject external disturbances. Simulation results are given to illustrate the effectiveness and robustness of the proposed algorithm. As the most simply measurable states of the system are used in suggested controllers, there is no need to design state space variable observer system.

Key words:FACTS, UPFC, Power Flow Control, Lyapunov Stability, Control Lyapunov Function, Sliding Mode Control

Keywords

• FACTS, UPFC, Power Flow Control, Lyapunov Stability, Control Lyapunov Function, Sliding Mode Control

References

1. Song, Y.H., and Johns, A.T. ‘Flexible AC
2. transmission systems (FACTS)’, IEE Power and Energy Series 30, London, UK, 1999
3. Zangeneh, A., Kazemi, A., Hajatipour, M., Jadid,
4. J., ‘A Lyapunov theory based UPFC controller for power flow control’, Electrical Power and Energy Systems, 31, 2009, pp. 302–308
5. Gyugyi, L. ‘A unified power flow control concept
6. for flexible AC transmission systems’. IEEE Proc – C 1992; 139(4) pp. 323–331.
7. Yam, C.M., Haque, M.H. ‘A SVD based controller
8. of UPFC for power flow control’. Electr Power Syst Res 2004; 70, pp. 76–84.

9. A. Ajami, A.M. Shotorbani, M.P. Aagababa,
10. ‘Application of the direct Lyapunov method for robust finite-time power flow control with a unified power flow controller’, IET Generation, Transmission & Distribution 2012; Volume 6, Issue 9, pp. 822-830
11. Al-Mawsawi, S.A. ‘Comparing and evaluating the
12. voltage regulation of a UPFC and STATCOM’. Int J Electr Power Energy Syst 2003; 25: pp. 735–740.
13. Gholipour, E., Saadate, S. ‘Improving of transient
14. stability of power systems using UPFC’. IEEE Trans Power Delivery 2005; 20(2): pp. 1677–1682.
15. M. KarbalayeZadeh, H. Lesani, Sh. Farhangi, ‘A
16. Novel Unified Power Flow Controller with Sub- Synchronous Oscillation Damping’, International Review of Electrical Engineering 2011; Vol. 6, No. 5, pp. 2386-2400.
17. Guo, J., Crow, ML., Sarangapani, J. ‘An improved
18. UPFC control for oscillation damping’. IEEE Trans Power Syst 2009; 14(1): pp. 288–296. Tiwari, S., Naresh, R., Jh, R. ‘Neural network predictive control of UPFC for improving transient stability performance of power system’, Applied Soft Computing 2011; 11 (8) pp. 4581-4590
19. Ma, TT., ‘P-Q decoupled control schemes using
20. fuzzy neural networks for the unified power flow controller’. Int J Electr Power Energy Syst 2007;29: pp. 748–758.
21. Sharma, N.K. Jagtap, P.P., ‘Modelling and
22. Application of Unified Power Flow Controller (UPFC)’, 3rd Emerging Trends in Engineering and Technology (ICETET), 2010, pp. 350 – 355. Conference on
23. A. Abbaszadeh, J. Soltani, B. Mozafari, F. Partovi
24. ‘Optimal Ga/Pso-Based Allocation of Facts Devices Considering Voltage Stability through Optimal Power Flow’, International Review of Electrical Engineering 2011; Vol. 6, No. 7, pp. 3065-3072.
25. Shayeghi, H., Shayanfar, H.A., Jalilzade, S.,
26. Safari, A. ‘A PSO based unified power flow controller oscillations’, Energy Conversion and Management 2009; 50, pp. 2583–2592. of power system
27. Ghane, H., Nikravesh, ‘A Nonlinear C-UPFC
28. Lu, B., Ooi, B.T., ‘Unified Power Flow Controller
29. (UPFC) under Nonlinear Control’, Proceedings of the Power Conversion Conference, 2002. PCC- Osaka 2002; (3) pp. 1118–1123.
30. Ilango, G.S., Nagamani, C., Aravindan, D.,
31. ‘Independent control of real and reactive power flows using UPFC based on adaptive back stepping’ TENCON 2008 - 2008 IEEE Region 10 Conference. pp. 1–6.
32. Alasooly, H., Redha, M.,: ‘Optimal control of
33. UPFC for load flow control and voltage flicker elimination and current harmonics elimination’, Computers and Mathematics with Applications 2010; 60, pp. 926–943.
34. Taher, S.A., Akbari, S., Abdolalipour A., and
35. Hematti, R.: ‘Design of Robust Decentralized Control for UPFC Controller Based on Structured Singular Value’, American Journal of Applied Sciences 2008; 5 (10) pp. 1269-1280.
36. Shalchi, F., Shayeghi, H., Shayanfar, H.A.,:
37. ‘Robust control design for UPFC to improve damping of oscillation in distribution system by H2 method’, 16th Conference on Electrical Power Distribution Networks (EPDC), 2011.
38. A. Colbia-Vega, J. de Leo´ n-Morales, L. Fridman,
39. O. Salas-Pena, M.T. Mata-Jimenez, ‘Robust excitation control design using sliding-mode technique for multi-machine power systems’, Electric Power Systems Research 2008; 78, pp. 1627–1634
40. V. Bandal, B. Bandyopadhyay, and A. M.