A micro-grid consisting of distributed generation resources (DGRs) with a hybrid energy storage system (HESS) composed of batteries and super-capacitors was studied. A control strategy based on the particle swarm optimization (PSO) and energy management algorithms was proposed to facilitate power distribution in the micro-grid and to improve the reliability, control levels, and penetration of micro-grids in the current electrical grids. The proposed operational strategy is based on the power predicted using the load profile and power generation resources. Energy management strategies were then presented by solving a multi-objective problem by the PSO algorithm and submitting the optimization results to the fuzzy controller and power distribution management (PDM) unit. The optimizer, the PDM unit, and the fuzzy controller provide a comprehensive operating procedure for the islanded and grid-connected micro-grids, taking into account their stability against grid fluctuations. In another part of this strategy, an auxiliary power control unit (APCU) was proposed for supporting the HESS and increasing the reliable performance of this unit. The proposed structure was applied to the net power (P-net) of the islanded and grid-connected micro-grids. The net power was divided into high-frequency (super-capacitor) and low-frequency (battery and APCU) components. The proposed algorithm and simulation results were analyzed using MATLAB/Simulink (C) 2020 ISA. Published by Elsevier Ltd. All rights reserved.