In this paper an intelligent fuzzy logic controller is proposed to control the frequency and voltage of a power generating system. The load frequency control (LFC) and automatic voltage regulator (AVR) are installed in each generator to control the real and reactive power flows. Due to rising and falling power demand, the real and reactive power balance is harmed and hence frequency and voltage get deviated from nominal value. This necessitates the need for an intelligent fuzzy controller to generate and deliver power in an interconnected system as economically and reliably as possible while maintaining the voltage and frequency within permissible limits. The conventional PID controllers employed for this task will have zero steady-state error but lead to large deviations in frequency and voltage under varying load conditions. The proposed method overcomes the drawbacks of a conventional fixed gain controller and improvement is achieved in terms of settling time, oscillations and overshoot. The single and two area LFC and AVR are modeled in MATLAB using the transfer function of the system. Fuzzy rules and membership functions are tuned based on the knowledge of experts and from previous experience about the plant behavior. The models are simulated for different load conditions and regulations in order to demonstrate the effectiveness of the proposed controller. Simulation results emphasise the improved performance in comparison with fixed gain controllers.
Anowar MS, Rabani MG, Hossain MF, Sheikh MRI and Rakibul Isalm M. ( 2006) Fuzzy frequency controller for an AGC for the improvement of power system dynamics, in Proceedings of the 4th International Conference on Electrical, Computer Engineering, 19-21 December , Dhaka, Bangladesh, pp. 5-8.
2.
Barjeev T. and Srivastava SC ( 2003) A fuzzy logic based load frequency controller in a competitive electricity environment, IEEE Paper No. 0-7803-7989-6/03.
3.
Chaturvedic DK, Satsangi PS and Kalra PK ( 1999) Load frequency control: a generalized neural network approach . Electric Power and Energy Systems21: 405-415.
4.
Chowdhury S., Chowdhury SP and Choudri S. ( 1999) Advanced digital load frequency control with unknown deterministic power demand for interconnected power systems. IE(I) Journal on Electrical Power System80: 87-95.
5.
Chown GA and Hartman RC ( 1998) Design and experience with a fuzzy logic controller for automatic generation control (AGC). IEEE Transactions on Power Systems13: 965-970.
6.
Ha QP and Negnevitsky M. ( 1995) A robust modal controller with fuzzy tuning for multi-masselectromechanical systems, in Proceedings of the Third Australian and New Zealand Conference on Intelligent Information Systems, University of Tasmania, Australia, pp. 214-219.
7.
Saadat Hadi (ed.) (1999) Power System Analysis, McGraw-Hill International edition. New Delhi, India: Hadi Saadat.
8.
Hasan Abul R., Thomas S Martis and Sadrul Ula AHM ( 1994) Design and implementation of a Fuzzy Controller based Automatic Voltage Regulator for a synchronous generator. IEEE Transactions on Energy Conversion9(3): 550.
9.
Juang CF and Lu CF ( 2005) Load frequency control by hybrid evolutionary fuzzy PI controller. IEE Proceedings On-line20050176: 196-204.
10.
Kaimal MR, Dasgupta S. and Harishankar M. ( 1997) Neuro-Fuzzy Control Systems. New Delhi : Narosa Publishing House.
11.
Karnavas KL and Papadopoulos DP ( 2002) AGC for autonomous power system using combined intelligent techniques. Electric Power System Research62: 225-239.
12.
Khodabakshian A. and Golbon N. ( 2005) Robust load frequency controller design for hydro power systems. Proceedings of the IEEE Conference on Control Applications, 28-31 August, Toronto, Canada.
13.
LaMeres BJ and Nehrir MH ( 1999) Fuzzy logic based voltage controller for a synchronous generator. IEEE Computer Applications in Power12(2): 46-49.
14.
Lu J., Nahrir MH and Pierre DA ( 2001) A fuzzy logic based adaptive power system stabilizer for multi-machine systems. Electric Power Systems Research60: 115-121.
15.
Mathur HD and Ghosh S. ( 2006) A comprehensive analysis of intelligent control for load frequency control, inIEEE Power India Conference 10 April, Delhi.
16.
Mathur HD and Manjunath HV ( 2007) Frequency stabilization using fuzzy logic based controller for multi-area power system. South Pacific Journal of Natural Science4: 22-30.
17.
Mitra P., Maulik S., Chowdhury SP and Chowdhury S. ( 2008) ANFIS based automatic voltage regulator with hybrid learning algorithm. International Journal of Innovations in Energy Systems and Power3(2): 1-39.
18.
Momoh JA, Ma XW and Tomsovic K. ( 1995) Overview and literature survey of fuzzy set theory in power systems, Paper # 95 WM 208-9 PWRS, in Transactions of IEEE PES Winter Power Meeting, January/February, NewYork .
19.
Mukherjee V. and Ghosal SP ( 2008) Velocity relaxed swarm intelligent tuning of fuzzy based power system stabilizer, in IEEE Power Engineering Society Conference 85, IEEE paper No.0-7803-9525-5/06.
20.
Nanda J. and Mangla A. ( 2004) Automatic generation control of an interconnected hydro-thermal system using conventional integral and fuzzy logic controller , in IEEE International Conference on Electric Utility Deregulation, Restructuring and Power Technologies, April, Hong Kong , pp. 372-379.
21.
Panda G., Panda S and Ardil C (2009) Hybrid neuro fuzzy approach for automatic generation control of two-area interconnected power system. International Journal of Computational Intelligence5(1): 80-84.
22.
Ramakrishnan S. and Selvan S. ( 2005) Fuzzy based image texture classification using wavelet packet transform, in Proceedings of 3rd National Conference on Mathematical & Computational Models, 15-16 December , PSG College of Technology, Coimbatore, pp. 514-520.
23.
Ross TJ ( 2005) Fuzzy Logic with Engineering Applications. New Delhi: McGraw Hill International Edition.
24.
Sambariya DK, et al. (2009) Fuzzy applications to single machine power system stabilizers . Journal of Theoretical and Applied Information Technology5: 317-324.
25.
Soundarrajan A., Krishnakumar R. and Subharani S. ( 2003) Intelligent controllers for automatic generation control , in Proceedings of the International conference on Robotics, Vision, Information and Signal Processing, January , Penang, Malaysia, pp. 307-311.
26.
Talaq J. and Al-Basri F. ( 1999) Adaptive fuzzy gain scheduling for load frequency control . IEEE Transactions on Power Systems14(1): 145-150.
27.
Thottungal R. and Anbalagan P. ( 2003) Control of load frequency for interconnected power system using fuzzy logic. Proceedings of the Twentyfifth National Systems Conference, 20-23 May, PSG College of Technology, India, pp. 76-79.
28.
Vinod Kumar DM ( 1998) Intelligent controllers for automatic generation control , in Proceedings of IEEE Region 10 International Conference on Global Connectivity in Energy, Computer, Communication and Control, 17-19 December, New Delhi, pp. 557-574.
29.
Wood AJ and Wollenberg BF ( 2006) Power Generation, Operation and Control. New York: John Wiley.
30.
Ying-Tung Hsiao ( 2004) Ant colony optimization for designing of PID controllers , in Proceedings of the IEEE International Symposium on Computer Aided Control Systems Design, 4 September, Taipei, Taiwan, pp. 321-325.
31.
Young-H Moon, Heon-Su Ryu, Jong-Gi Lee, Kyung-Bin Song and Myong-Chul Shin ( 2002) Extended integral control for load frequency control with the consideration of generation rate constraints. Electrical Power and Energy Systems24: 263-269.
32.
Yukita K., Goto Y., Mizuno K., Miyafuji T., Ichiyanagi K. and Mizutani Y. ( 2000) Study of load frequency control using fuzzy theory by combined cycle power plant. Proceedings of IEEE Power Engineering Society Winter Meeting, 422-427, I.
33.
Zeynelgil HL, Demiroren A. and Sengor NS ( 2002) The application of ANN technique for automatic generation control for multi-area power system. Electric Power and Energy Systems24: 345-354.
