Development of Optimal PI Controllers of an Inverter–Based Decentralized Energy Generation System Based on Equilibrium Optimization Algorithm

Abstract

The microgrid model gained considerable interest in the electricity industry due to increased financial and environmental benefits. The microgrid views decentralized generation (DG) and associated loads as a subsystem. The controlling methodology is the voltage source converter (VSC) cascaded-type converters technique, which depends on the Proportional-Integral (PI) controller. In this paper, the optimal tuning of the PI controller parameters is formulated as a constrained optimization problem for the system under different conditions (i) The system is converted from on-grid to off-grid mode at Time = 2 s. (ii) The system is subjected to three lines to earth fault in an off-grid mode. (iii) The system is subjected to load variation in an off-grid mode. The equilibrium optimization algorithm (EO) is physics-based optimization to tune the gains of the PI controller. The proposed approach (EO) has been compared with results from other approaches such as Genetic Algorithm (GA) which is inspired by a natural evolution process, Salp Swarm Algorithm (SSA) which is inspired by the swarming behaviour of salp in oceans. Simulations are conducted using MATLAB/Simulink software. The EO performs perfectly and has a fine ability to tune controller gains with smaller errors than other approaches.