Abstract:

In this study, a particle swarm optimization (PSO) algorithm-based Proportional-Integral-Derivative (PID) controller is proposed for the Automatic Voltage Regulator (AVR) system terminal tracking problem in the existence of time-delay and varying loads. AVR is a commonly used electronic device for maintaining generator output terminal voltage at a given reference under time-delays and varying load thus introduces a challenging electrical system problem. Time-delays exist in many real-world systems due to the lags in transmission and transport, in general, they have a negative effect on the stability and control design. In this research, the time delay is approximated by Pade approximation leading to the so-called non-minimum phase system. A nonminimum phase system represents the difficulty of controlling due to its zeroes in the complex right half side of the s-plane. To this aim, we utilize a PID controller, its design and application widely studied in real-time systems, thus it is a suitable selection for the AVR system. The optimal controller gains Kp, Ki, and Kd are optimized with the proposed PSO algorithm based on a commonly used error minimization objective function. The PSO-based optimal PID controller’s performance is analyzed with several methods including root locus, bode analysis, robustness, and disturbance rejection. It is demonstrated that the proposed PID controller improves the reference terminal voltage tracking performance of the AVR system. According to the obtained results, it has been revealed that the proposed PSO-based PID controller improves tracking properties under time-delay and load change thus it can be effectively used for synchronous generator automatic voltage regulator (AVR) system terminal voltage stability.

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