Design of an optimal PID controller in AC-DC power system using modified genetic algorithm

HVDC power transmission systems can overcome some limitations inherent with AC power transmission systems such as transmission over long distance and transmission with cable. One aspect of importance is the improvement in stability achieved with AC-DC power transmission. In this paper a methodology for the optimal proportional integral derivative (PID) controller design using the modified genetic algorithm (MGA) is proposed to improve the transient stability of AC-DC power systems after faults. This study consists of the formulation of load-flow calculation, basic controls on HVDC transmission system, mathematical model selection for stability analysis, and supplementary signal control by an optimal PID controller using the MGA. The proposed method is verified using computer simulation. The results show the application of the MGA-PID controller in AC-DC power systems has improved the transient stability. The PID controller design using MGA method has been shown to be advantageous when applied for the AC-DC power systems.