Application of AI supported optimal controller for automatic generation control of a restructured power system with parallel AC–DC tie lines

Abstract

SUMMARYAn optimal controller has been designed for automatic generation control (AGC) of two‐area restructured power system. The performance of the controller has been studied for two cases: (a) when the tie line connecting the two areas consists of parallel EHVAC and HVDC lines and (b) when HVDC link is absent and only ac tie line acts as interconnection. The comparison has been done for the two cases in terms of time taken to damp out oscillations of frequency in each area, tie‐line power exchange between the two areas and power generated by each generator when there is change in load. The simulation results indicate that control performance improves when HVDC link is connected in parallel with EHVAC tie line and output of the dc block is considered as additional state for the optimal controller. Detailed simulation studies were carried out for load demand by DISCOs as per cotracted condition as well as for bilateral contract violation condition. Optimal controller gives better dynamic response compared to conventional PI controller. AGC dynamic response is further improved by using combined optimal fuzzy controller. Particle swarm optimization (PSO) technique has been used for tuning the fuzzy controller. The results of the two area thermal–thermal system indicate better control performance in terms of peak overshoot and settling time by PSO tuned combined optimal fuzzy controller as compared to the un‐tuned controller. Copyright © 2011 John Wiley & Sons, Ltd.