Robust Frequency Control in an Islanded Microgrid: A Novel Stochastic Fractal Search Algorithm Approach

Abstract

This paper presents a robust frequency control in an islanded ac microgrid (MG). The microgrid considered in this paper consists of distributed energy sources (DES). These include micro-turbine (MT), diesel engine generator (DEG), fuel cell (FC), renewable energy sources like wind turbine (WT), photovoltaic panels (PV), and energy storage systems like battery energy storage system (BESS) and flywheel energy storage system (FESS). The load fluctuation, wind power fluctuation and solar irradiation fluctuation often influence the frequency of the MG. So to tackle this problem, a proportional-integral-derivative controller (PID) is designed and optimized by using the stochastic fractal search (SFS) algorithm. The proposed controller is very effective and able to eliminate the frequency deviation in a short time. The time-domain simulation results obtained by SFS based PID controller are compared with the results obtained by SFS based PI controller to show the effectiveness of the proposed controller. From the comparison, it can be observed that proposed controller gives better frequency stability and hence improves the frequency of the MG significantly.