In this paper, an algorithm for the maximum extraction of energy generated by photovoltaic (PV) systems was presented. The tracking of the global maximum point of the system is complex due to the non-linearity of the current-voltage (I-V) characteristic curve of the photovoltaic modules, as they vary according to the temperature and solar irradiation in the module. To obtain the best energy efficiency in these systems, it is important that the generation is delivering the maximum power available through the arrangement. In order to solve such problems, in this work an efficient MPPT-FA method was proposed, which showed good traceability when compared to traditional methods. Most traditional MPPT techniques are not able to find the global maximum point to extract the maximum power provided by the PV system. Finally, the Firefly Metaheuristic MPPT method proved to be robust against several partial shading scenarios. Simulations were presented to demonstrate the effectiveness of the proposal when compared to the traditional MPPT-PO method.

This work aims to present an electrical power management system, between a photovoltaic generation system and a battery energy storage system, by using a low-power dual-stage microinverter connected to the electrical distribution network, configuring a nanogrid. The presented system is capable of performing the active power injection of the photovoltaic arrangement, increasing the availability of electrical energy through a maximum power point tracking algorithm. The system is also able to manage the processes of the charge and discharge of the battery system, where the energy storage system will serve as grid support when renewable power is not available. Furthermore, to ensure the quality of electric energy the proposed microinverter also has the characteristic of parallel active filter for suppression of harmonic currents and reactive compensation of local load current, ensuring the quality of electric energy. As a result, this work presents the system topology, modeling and control of electronic converters, the management strategy with its modes of operation and the results of numerical validation of the proposed system.

Several management and control techniques for hybrid energy storage systems (HESS) with batteries and supercapacitors are presented in the literature applied to microgrids (MGs). The filter-based control strategy for defining the control loop actuation is one of the most widely used approaches with satisfactory performance. Variations of the Filter-Based Method (FBM) method are proposed to improve the control efficiency of the HESS under load disturbance and intermittent generator sources. However, not enough attention has been paid to the impacts of MG on the operational performance of batteries, despite the fact that they represent a non-negligible percentage of the total cost of MGs. In this paper, a control strategy called FBM-CSoC is proposed that focuses primarily on mitigating battery safety and degradation issues. The control strategy proposes a distribution of the charging and discharging current in a weighted proportional way to the normalized rated capacity and current state of charge (SoC) of each battery in the MG. This control strategy favors both the reduction of the internal temperature variation of the cells and the possibility of them operating in overcharging or over-discharging conditions. A comparative case study between the traditional FBM method and the FBM-CSoC, by means of numerical simulations, demonstrated that the load distribution occurs satisfactorily in energy storage systems. Finally, the FBM-CSoC method can be flexibly used for different types of battery technology and/or batteries with different SoCs integrated with supercapacitors.

This article presents the development of a Three-Phase Interleaving Phase-Shifted Full Bridge (PSFB) DC-DC converter for green hydrogen generation. The converter implements Zero Voltage Switching (ZVS) and GaNFETs in the primary side of the transformer, and incorporates an Active Clamp system with synchronous rectification in the secondary side. These features are designed to minimize switching losses and significantly improve the power conversion efficiency. Simulation results confirm the effectiveness of these design choices, showcasing improved waveforms and stable operation. This work contributes to the advancement of power electronics in the field of green hydrogen production, offering a promising solution to increase efficiency and enhance the overall power quality of hydrogen generation processes.

Given the climate change observed in the past few decades, sustainable development and the use of renewable energy sources are urgent. In this scenario, hydrogen production through electrolyzers is a promising renewable source and energy vector because of its ultralow greenhouse emissions and high energy content. Hydrogen can be used in a variety of applications, from transportation to electricity generation, contributing to the diversification of the energy matrix. In this context, this paper presents an autonomous isolated DC microgrid system for generating and storing electrical energy to be exclusively used for feeding an electrolyzer hydrogen production plant, which has been retrofitted for green hydrogen production. Experimental verification was performed at Itaipu Parquetec, which consists of an alkaline electrolysis unit directly integrated with a battery energy storage system and renewable sources (e.g., photovoltaic and wind) by using an isolated DC microgrid concept based on DC/DC and AC/DC converters. Experimental results revealed that the new electrolyzer DC microgrid increases the system’s overall efficiency in comparison to the legacy thyristor-based power supply system by 26%, and it autonomously controls the energy supply to the electrolyzer under optimized conditions with an extremely low output current ripple. Another advantage of the proposed DC microgrid is its ability to properly manage the startup and shutdown process of the electrolyzer plant under power generation outages. This paper is the result of activities carried out under the R&D project of ANEEL program No. PD-10381-0221/2021, entitled “Multiport DC-DC Converter and IoT System for Intelligent Energy Management”, which was conducted in partnership with CTG-Brazil.

The solar energy has been considered by many researchers the most promising source energy of the future. However, the applicability of photovoltaic panels depends on several factors, such as the efficiency and cost. Nowadays, besides its low efficiency, the photovoltaic (PV) array is considered a very expensive technology. As a result, it is necessary to improve the ways of adapting the available energy provided by the photovoltaic arrays. Once the available DC voltage provided by photovoltaic panels is low to connect the PV system to the grid via a DC-AC converter, it becomes necessary to use of step-up DC-DC converters. Thus, they must be designed to avoid any waste of energy. This paper deals with the simulation and analysis by comparison of several topologies of step-up DC-DC converters, addressing aspects of extreme importance for application in photovoltaic systems, such as the efficiency of the DC-DC converters. A energia solar tem sido considerada por muitos pesquisadores como a mais promissora das fontes de energia do futuro. Contudo, a aplicabilidade de painéis fotovoltaicos depende de diversos fatores, tais como eficiência e custo. Nos dias de hoje, além de sua baixa eficiência, o painel fotovoltaico é ainda considerado uma tecnologia cara. Em função disso, é necessário aprimorar ao máximo os meios de adaptação da energia oferecida pelos painéis. Uma vez que, em algumas aplicações, a tensão c.c. disponibilizada pelos painéis fotovoltaicos (FV) é baixa quando se deseja conectar o sistema FV na rede elétrica através de um conversor c.c.-c.a., torna-se necessária a utilização de conversores c.c.-c.c. elevadores. Assim, estes devem ser projetados de modo a evitar qualquer desperdício de energia. Este trabalho visa a simulação e análise por comparação de algumas topologias de conversores c.c.-c.c. elevadores, abordando aspectos de extrema importância para aplicação em painéis fotovoltaicos, tal como a eficiência dos conversores.