AGC of a multi-area thermal system under deregulated environment using a non-integer controller

Abstract This paper presents automatic generation control (AGC) of multi-area thermal systems under deregulated environment considering reheat turbines and appropriate generation rate constraints (GRC). The performance of a fractional-order Proportional–Integral–Derivative (FOPID) controller is evaluated for the first time in AGC of the proposed systems. Performances of several integer order (IO) controllers have been evaluated and are compared with FOPID controller. Investigation reveals that FOPID controller provides better dynamic performance than the IO controllers in both equal and unequal area system. Bacterial foraging (BF) technique is used for simultaneous optimization of the gains and other parameters such as order of integrator ( λ ) and differentiator ( μ ) in case of FOPID controller and speed regulation parameter ( R ) and such optimization results higher value of R which is welcome for simple and cheaper realization of governor. Further, Sensitivity analysis is carried out for the first time in the system considered to investigate the robustness of the optimum gains, λ and μ of FOPID controllers and R parameters obtained at nominal condition. Analysis expose that parameters obtained at nominal conditions need not be reset to wide changes in system condition, parameters, size and position of step load perturbation (SLP). Investigations on higher order of contract violation reveal that FOPID controller performed better than other IO controller.

[1]  Sakti Prasad Ghoshal,et al.  Optimized multi area AGC simulation in restructured power systems , 2010 .

[2]  Olle I. Elgerd,et al.  Electric Energy Systems Theory: An Introduction , 1972 .

[3]  Nasser Sadati,et al.  Design of a fractional order PID controller for an AVR using particle swarm optimization , 2009 .

[4]  K. Miller,et al.  An Introduction to the Fractional Calculus and Fractional Differential Equations , 1993 .

[5]  Muwaffaq I. Alomoush,et al.  Load frequency control and automatic generation control using fractional-order controllers , 2010 .

[6]  YangQuan Chen,et al.  Fractional order PID control of a DC-motor with elastic shaft: a case study , 2006, 2006 American Control Conference.

[7]  P. Sangameswara Raju,et al.  Automatic generation control of TCPS based hydrothermal system under open market scenario: A fuzzy logic approach , 2009 .

[8]  R. D. Christie,et al.  Load frequency control issues in power system operations after deregulation , 1995 .

[9]  Gerald B. Sheblé,et al.  AGC simulator for price-based operation. I. A model , 1997 .

[10]  I. Podlubny Fractional-order systems and PIλDμ-controllers , 1999, IEEE Trans. Autom. Control..

[11]  Loi Lei Lai,et al.  GA optimized PID controllers for automatic generation control of two area reheat thermal systems under deregulated environment , 2008, 2008 Third International Conference on Electric Utility Deregulation and Restructuring and Power Technologies.

[12]  Javad Sadeh,et al.  Practical Viewpoints on Load Frequency Control Problem in a Deregulated Power System , 2010 .

[13]  Amit Patra,et al.  Load following in a bilateral market with local controllers , 2011 .

[14]  Igor Podlubny,et al.  Fractional-order systems and PI/sup /spl lambda//D/sup /spl mu//-controllers , 1999 .

[15]  Lalit Chandra Saikia,et al.  Performance comparison of several classical controllers in AGC for multi-area interconnected thermal system , 2011 .

[16]  Y. Chen,et al.  A comparative introduction of four fractional order controllers , 2002, Proceedings of the 4th World Congress on Intelligent Control and Automation (Cat. No.02EX527).

[17]  G. Sheblé,et al.  AGC simulator for price-based operation. II. Case study results , 1997 .

[18]  Alain Oustaloup,et al.  The CRONE Control of Resonant Plants: Application to a Flexible Transmission , 1995, Eur. J. Control.

[19]  S. Mishra,et al.  Maiden Application of Bacterial Foraging-Based Optimization Technique in Multiarea Automatic Generation Control , 2009, IEEE Transactions on Power Systems.

[20]  M. A. Pai,et al.  Simulation and Optimization in an AGC System after Deregulation , 2001, IEEE Power Engineering Review.