Control of hybrid DC/AC microgrid system employing fuel cell and solar photovoltaic sources using grey wolf optimization

Abstract

The outcome of this study is to improve and enhance the power quality of the hybrid DC/AC microgrid (MG). The photovoltaic (PV) system and the proton exchange membrane fuel cell (PEMFC) are used as renewable energy sources to deliver the optimum active power to the utility grid. The MG system based on the PV system, PEMFC and voltage source inverter is modelled mathematically. Also, the maximum power point tracking (MPPT)-based grey wolf optimization (GWO) is used to increase the PV module efficiency and enhance performance. Also, to improve the PEMFC performance, a digital proportional-integral controller is used to control the PEMFC circuit. The proposed inverter is controlled using synchronous reference frame theory, called the direct-quadrature (dq) control method. Hence, the performance of the proposed MG system is tested using MATLAB® for various weather and loading conditions. From the simulation results, the proposed MG system can deliver and absorb an active power based on the PV and fuel cell characteristics. As a result, the hybrid DC/AC MG is enhanced in terms of stabilization of the DC-bus voltage. Also, the power quality of the MG is improved using GWO optimization based on MPPT. Finally, good results are achieved using GWO in terms of the total harmonic distortion of the output current of 2.3% and higher efficiency of 98.9%.