Abstract:
In an islanded microgrid, the system operating frequency and voltage is governed by the socalled
droop based relationships due to the absence of conventional slack bus which necessitates
incorporation of various controllers. The parameters of the controllers play a vital role ensuring
stable and reliable supply of power to the connected consumers. In this work, a two-stage
optimal tuning procedure is presented for controlling a two inverter based microgrid system
under isolated mode of operation. At rst, the key control parameters in
uencing the transient
response of the system are identi ed. Next, an eigenvalue based optimization process has been
adopted in which three population based search algorithms: Genetic Algorithm (GA), Particle
Swarm Optimization (PSO) algorithm and Grey Wolf Optimization (GWO) algorithm are used
in order to nd out the initial range of controller parameters in an unbounded search space.
In the second stage of optimization, Exhaustive Search (ES) and Interior Point (IP) based
search algorithms are adopted to obtain the optimized value within the bounds provided by the
population based search algorithms. At the end, time domain and comparative analyses among
these combinational algorithms are presented to determine the most e ective algorithm for the
studied islanded microgrid system. The simulation results show that the performance of GA is
inferior compared to other two algorithms: PSO and GWO. GWO provides better optimization
in comparatively lesser amount of time than PSO in the rst stage and in the second stage, IP
yields better optimization than ES. Consequently, the two stage optimization process suggests
that GWOIP could be chosen for the design problem.
