# Fuzzy Applications in a Multi-Machine Power System Stabilizer

• Accepted : 2010.05.17
• Published : 2010.09.01

#### Abstract

This paper proposes the use of fuzzy applications to a 4-machine and 10-bus system to check stability in open conditions. Fuzzy controllers and the excitation of a synchronous generator are added. Power system stabilizers (PSSs) are added to the excitation system to enhance damping during low frequency oscillations. A fuzzy logic power system stabilizer (PSS) for stability enhancement of a multi-machine power system is also presented. To attain stability enhancement, speed deviation ($\Delta\omega$) and acceleration ($\Delta\varpi$) of the Kota Thermal synchronous generator rotor are taken as inputs to the fuzzy logic controller. These variables have significant effects on the damping of generator shaft mechanical oscillations. The stabilizing signals are computed using fuzzy membership functions that are dependent on these variables. The performance of the fuzzy logic PSS is compared with the open power system, after which the simulations are tested under different operating conditions and changes in reference voltage. The simulation results are quite encouraging and satisfactory. Similarly, the system is tested for the different defuzzification methods, and based on the results, the centroid method elicits the best possible system response.

#### References

1. E.V. Larsen and D.A. Swann, “Applying Power System Stabilizers Part 1: General Concepts,” IEEE Transactions on Power Apparatus and Systems, Vol. PAS-100, No. 6, June 1981, pp. 3017-3024. https://doi.org/10.1109/TPAS.1981.316355
2. Rajeev Gupta, “Robust Non-dynamic Multi-rate Output Feedback Technique based Power System Stabilizer,” Ph. D. Thesis, IIT, Bombay (India), 2004.
3. M.A.M Hassan, O.P. Malik, and G.S. Hope, “A Fuzzy Logic Based Stabilizer for Synchronous Machine,” IEEE Transactions on Energy Conversion, Vol. 6, No. 3, September 1991, pp. 407-413. https://doi.org/10.1109/60.84314
4. Yuan-Chyuan Lee and Chi-Jui, “Damping of Power System Oscillations with Output Feedback and Strip Eigenvalue Assignment,” IEEE Tran. on PAS, Vol. 10, No. 3, August 1995, pp. 1620-1626.
5. Y.Y. Hsu and C.Y. Hsu, “Design of a Proportional-Integral Power System Stabilizer,” IEEE Trans. On PAS, 1(2), 1986, pp. 46-53.
6. C.J. Wu and Y.Y. Hsu, “Self-tuning Excitation Control for Synchronous Machine,” IEEE Tran. On AES, Vol. 22, 1986, pp. 389-394.
7. Y.Y. Hsu and C.H. Chang, “Design Fuzzy Power System Stabilizer for Multi-machine Power System,” IEE Proc., Vol. 137, Pt.c., No. 3, May 1990.
8. H.J. Zimmermann, “Fuzzy Set Theory and Its Application,” Kluwer-Nijoff Publishing Company, 1985.
9. Byung-Jae Choi, Seong-Woo Kwik, and Byung Kook Kim, “Design and Stability Analysis of Single-Input Fuzzy Logic Controller,” IEEE Trans. On System, Man and Cybernetics, Vol. 30, No. 2, April 2000.
10. L.A. Zadeh, Fuzzy Sets, Inf. and Control 8, 1965, pp. 38-353.
11. K.R. Padiyar , “Power system dynamics stability and control,” Interline publications, Bangalore, 1997.
12. P. Kundur, “Power System Stability and Control,” McGraw-Hill, Inc., New York, 1993.

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