Variable structure fuzzy gain scheduling based load frequency controller for multi source multi area hydro thermal system

• Published in: International journal of electrical power & energy systems 2013-12, Vol.53, p.375-381
• Main Authors: Vijaya Chandrakala, K.R.M., Balamurugan, S., Sankaranarayanan, K.
• Format: Article
• Language: English
• Subjects: Applied sciences; Control systems; Electric power plants; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Exact sciences and technology; Fuzzy; Fuzzy gain scheduling; Fuzzy logic; Fuzzy set theory; Gain scheduling; Genetic algorithm; Genetic algorithms; Hydro thermal system; Hydroelectric power plants; Load frequency control; Miscellaneous; PI controller; Power networks and lines; Regulation and control; Thermal power plants; Thermoelectricity; Variable structure
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2013.05.009

[Display omitted] •Each control area contains both hydro and thermal plant.•PI controller is tuned using ZN method, genetic algorithm and fuzzy gain scheduling.•The variable structure system is integrated with fuzzy gain scheduling. In this paper, variable structure fuzzy gain scheduling is proposed for solving the load frequency control problem of multi source multi area hydro thermal power system. The two control areas are connected via tie line. Each area comprises of both hydro and thermal power plant. The area frequency and tie line power oscillates during load variations are controlled by primary governor controller and secondary Proportional Integral (PI) controller. The PI controller gains are tuned using Ziegler Nichols’ (ZN) method and Genetic Algorithm (GA). ZN method is for conventional bench marking and GA is based on search in the space. In both the methods, the gain values of PI controllers are fixed for any system changes and it is not acceptable. This problem is overcome by scheduling the gain based on system changes using Fuzzy Logic. Finally, Variable Structure System of switching P to PI controller during transient to steady state is integrated with fuzzy gain scheduling. On evaluating all the controller performance based on performance indices, variable structure fuzzy gain scheduling provides better response for multi source multi area hydro thermal power system.