Tuning of Fractional Order PI λ D μ Controllers using Evolutionary Optimization for PID Tuned Synchronous Generator Excitation System

摘要

This paper has propounded the notion of the design of cascaded integer order (IO) PID - fractional order (FO)PIλDμcontroller by evolutionary multi-objective based optimization approach for a synchronous generator excitation system. The three contradicting performance indices have been framed in time domain as well as in frequency domain to minimize error, escalate the robust stability and to minimize the energy consumption. This paper propounded the issue of contradiction in minimizing error, escalation of robust stability and minimization of energy consumption by framing cascaded IO PID - FO PID controllers as multi-objective optimization problem. The optimization problem is solved to generate the design parameter that meets the competitive multi-objective specifications relating to performance, robust stability and to optimal control by making trade-off between them and respective weightage given to each objective function. The solution generates the non-dominated set of Pareto-optimal solutions and allows the designer to select a particular controller configuration with respective weightages. With the application of this proposed design to the excitation system of synchronous generator to a power plant’s, the dynamic robust stability enhanced explicitly with minimum energy consumption.