Optimizing Reliability of PV based Microgrid by Integrating Fuel Cell

Abstract

In the last few decades, solar photovoltaic (PV) based DC microgrids (MG) have become increasingly popular in applications such as electric vehicle (EV) charging, domestic and commercial power sup-plies etc. However, due to the uncertainty in solar power generation, the reliability of such systems is low for standalone applications, and hence, energy storage systems (ESS) are necessary to maintain power flow when power generation is not sufficient due to low irradiance or during night time. In solutions where batteries are used as ESS is bulky, heavy, and slow in response due to low power density, and therefore, not suitable for applications requiring fast transient response. Fuel cell (FC) technol-ogy on the other hand has become a promising non-conventional energy source featuring both high energy density and power availability, though has slow dynamic response. Furthermore, the compactness and portable feature of FC enable it to to use in almost every field that uses battery as ESS (BESS). In this work, an existing DC MG consisting of solar PV, BESS, and DC load is considered. The solar PV and the battery are connected to the MG DC bus via buck and bi-directional DC-DC converters respectively, whereas the FC is integrated using a boost con-verter. The Perturb and Observe (P&O) maximum power point tracking (MPPT) algorithm is implemented to track the maximum power point (MPP) of both PV and FC. Here, the DC bus voltage is maintained at 48 V by the bi-directional converter using a Proportional-Integral (PI) controller. This work highlights the MPPT of FC and the integration of solar PV, BESS, and FC to the DC MG leading to cleaner and more efficient energy solution.