Effective Energy Management Framework for Standalone Photovoltaic Fuel Cell Direct Current Microgrid without Auxiliary Storage Devices

Abstract

The objective of this paper was to propose an effective energy management framework for a standalone Photovoltaic–Fuel Cell Direct-Current (PV–FC DC) microgrid without auxiliary storage devices using an appropriate standard control strategy. The proposed framework demonstrates that accurate source sizing combined with coordinated power balancing can inherently maintain DC bus voltage stability through real-time generation–load equilibrium. The PV array operates as the primary energy source under high irradiance conditions using a perturb and observe, P&O algorithm for maximum power point tracking. This is then combined with a PEMFC subsystem, interfaced through a two-phase interleaved boost converter that compensates for power deficits during low solar availability. The EMS continuously evaluates the instantaneous power mismatch and generates a reference current for the fuel cell to restore equilibrium without centralized voltage reference enforcement. Simulation results under step irradiance variation demonstrate smooth source transition, negligible overshoot of <5% and tight DC bus regulation within ±1.25%. The findings confirm that DC bus stability can be achieved as a direct consequence of power balance rather than aggressive hierarchical voltage control. The proposed architecture eliminates battery storage, thereby reducing system complexity, cost, and maintenance requirements. Moreover, the EMS improves hydrogen utilization efficiency by activating the fuel cell only during periods of insufficient solar generation. As a result, hydrogen fuel is conserved and used strictly when a solar power deficit occurs. This operating strategy makes the system particularly suitable for medium power standalone applications such as remote telecommunication stations and rural electrification systems.