Design of Optimal Linear Quadratic Gaussian (LQG) Controller for Load Frequency Control (LFC) using Genetic Algorithm (G.A) in Power System
(International Journal of Engineering Works)
Vol. 5, Issue 3, PP. 40-49, March 2018
Load Frequency Control, Linear Quadratic Regulator, Linear Quadratic Gaussian, Kalman Filter, Genetic Algorithm
Nowadays power demand is increasing continuously and the biggest challenge for the power system is to provide good quality of power to the consumer under changing load conditions. When real power changes, system frequency gets affected while reactive power is dependent on variation in voltage value. For satisfactory operation the frequency of power system should be kept near constant value. Many techniques have been proposed to obtain constant value of frequency and to overcome any deviations. The Load Frequency Control (LFC) is used to restore the balance between load and generation by means of speed control. The main goal of LFC is to minimize the frequency deviations to zero. LFC incorporates an appropriate control system which is having the capability to bring the frequency of the Power system back to original set point values or very near to set point values effectively after the load change. This can be achieved by using a conventional controller like PID but the conventional controller is very slow in operation. Modern and optimal controllers are much faster and they also give better output response than conventional controllers. Linear Quadratic Regulator (LQR) is an advanced control technique in feedback control systems. It’s a control strategy based on minimizing a quadratic performance index. In despite of good results obtained from this method, the control design is not a straight forward task due to the trial and error involved in the selection of weight matrices Q and R. In this case, it may be hard to tune the controller parameters to obtain the optimal behaviour of the system. The difficulty to determine the weight matrices Q and R in LQR controller is solved using Genetic Algorithm (G.A). In this research Paper, G.A based LQG controller which is the combination of LQR and Kalman Filter is feedback in LFC using MATLAB/SIMULINK software package. Reduction in frequency deviations and settling time was successfully achieved by using LQG Controller with LFC based on G.A.
- Muddasar Ali: Lecturer & Researcher, Faculty of Electrical Engineering, Wah Engineering College (WEC), University of Wah, Pakistan. Email:firstname.lastname@example.org, Cell: +92-332-5417228
- Syeda Tahreem Zahra: Electrical Engineer & Researcher, Department of Electrical Engineering, University of Engineering & Technology (U.E.T), Taxila, Pakistan.
- Khadija Jalal: Lecturer & Electrical Engineer, Faculty of Electrical Engineering, Army Public College of Management & Science (APCOMS), Rawalpindi, Pakistan.
- Ayesha Saddiqa: Lab Engineer & MSc Scholar, Faculty of Electrical Engineering, Army Public College of Management & Science (APCOMS), Rawalpindi, Pakistan.
- Muhammad Faisal Hayat: Lab Engineer & MSc Scholar, Faculty of Electrical Engineering, Wah Engineering College (WEC), University of Wah, Pakistan.
Muddasar Ali, Syeda Tahreem Zahra, Khadija Jalal, Ayesha Saddiqa, Muhammad Faisal Hayat, "Design of Optimal Linear Quadratic Gaussian (LQG) Controller for Load Frequency Control (LFC) using Genetic Algorithm (G.A) in Power System" International Journal of Engineering Works, Vol. 5, Issue 3, PP. 40-49, March 2018.
-  P. Prajapati, “Multi-Area Load Frequency Control (LFC) by various Conventional Controllers using Battery Energy Storage System (BES),” International Conference on Energy Efficient Technologies for Sustainability (ICEETS) , ISSN: 978-1-4673, IEEE, 2016.
-  G. S. Thakur, “Load frequency control (LFC) in single area with traditional Ziegler-Nichols PID tuning controller,” International Journal of Research in Advent Technology, vol. 2, no. 12, E-ISSN: 2321-9637, December 2014.
-  M. Pal, “To Control Load Frequency by using Integral Controller,” International Journal of Innovative Research in Science, Engineering and Technology, (An ISO 3297: 2007 Certified Organization), vol. 3, no. 5, May 2014.
-  M. Wadi, “Optimal Controller for Load Frequency Control via LQR and Legendre wavelet function,” Journal of Automation and Control, vol. 3, no. 2, pp. 43-47, © Science and Education Publishing, DOI: 10.12691/ automation-3-2-2, 2015.
-  A. M. YOUSEF, “Improved Power System Stabilizer by Applying LQG Controller,” Advances in Electrical and Computer Engineering, ISBN: 978-1-61804-279-8.
-  P.S. Kumar, “Load Frequency Control Of Multi Area Power System Using Fuzzy And Optimal Control Techniques,” International Journal of Recent Trends in Engineering & Research (IJRTER), vol. 2, no. 8, ISSN: 2455-1457, August 2016.
-  S. K. Joshi, “Analysis of Load Frequency Control (LFC) using PID Controller,” International Journal of Emerging Technology and Advanced Engineering, ISSN 2250-2459, ISO 9001:2008 Certified Journal, vol. 4, no. 11, November 2014.
-  Hadi Saadat, “Power System Analysis,” PSA Publishing, 2010
-  Stefani, “Design of Feedback Control Systems,” 4th ed.
-  A. Tewari, “Modern control design with Matlab”.
-  A. H. Khan, “Optimized Reconfigurable Control Design for Aircraft using Genetic Algorithm,” Research Journal of Applied Sciences, Engineering and Technology, vol. 6, no. 24, ISSN: 2040-7459; e-ISSN: 2040-7467, Maxwell Scientific Organization, 2013.
-  Bingbing Wu, “Design and implementation of the inverted pendulum optimal controller based on hybrid genetic algorithm,” International Conference on Automation, Mechanical Control and Computational Engineering, (AMCCE 2015).
-  S. A. Ghoreishi, “Optimal Design of LQR Weighting Matrices based on Intelligent Optimization Methods,” International Journal of Intelligent Information Processing, vol. 2, no. 1, March 2011.
-  K. J, Astrom, and R. M. Murray, “An Introduction to Feedback System,” Princeton University Press, April 2010.
-  C. Concordia, and L. K. Kirchmayer, “Tie line power and frequency control of electric power systems,” Amer. Inst. Elect. Eng. Trans., Pt. II, vol. 72, pp. 562 572, June 1953.
-  N. Cohn, “Some Aspects of Tie-line Bias Control on Interconnected Power Systems,” Amer. Inst. Elect. Eng. Trans., vol. 75, pp. 1415-1436, February 1957.
-  O. I. Elgerd, and C. Fosha, “Optimum Megawatt Frequency Control of Multi-area Electric Energy Systems,” IEEE Trans. Power App. Syst., vol. PAS-89, no. 4, pp. 556–563, April 1970.
-  R. K. Green, “ Transformed Automatic Generation Control,” IEEE Trans.Power Syst., vol. 11, no. 4, pp. 1799–1804, November 1996.
-  D. Das, J. Nanda, M. L. Kothari, and D. P. Kothari, “Automatic Generation Control of Hydro Thermal system with new area control error considering generation rate constraint,” Elect. Mach. Power Syst., vol. 18, no. 6, pp. 461– 471, Nov./Dec. 1990
-  R. K. Cavin, M. C. Budge Jr., and P. Rosmunsen, “An Optimal Linear System Approach to Load Frequency Control (LFC),” IEEE Trans. On Power Apparatus and System, pp. 2472-2482, PAS-90, Nov./Dec. 1971.
-  V. F. Montagner, “A Robust LQR Applied To A Boost Converter With Response Optimized Using A Genetic Algorithm,” Power Electronics and Control Research Group, Federal University of Santa Maria ,97105-900, Santa Maria, RS, Brazil.
-  M. D. Youns, “Optimization Control of DC Motor with Linear Quadratic Regulator and Genetic Algorithm Approach,” Tikrit Journal of Engineering Sciences, vol. 20, no.5, June 2013.
-  Q. Wang, “An Overview of Genetic Algorithms Applied to Control Engineering Problems,” Proceedings of the Second International Conference on Machine Learning and Cybernetics, Xi’an, pp. 2-5, November 2003.