A single-phase common-mode transformerless grid-connected photovoltaic (PV) converter, which is based on the integration of two stages, is proposed in this paper. Transformer elimination in grid-connected PV systems has many advantages. It not only reduces cost, size, and weight but also increases the complete system efficiency. Since there is no galvanic isolation between grid and PV array, a leakage current may appear due to the PV parasitic capacitance to the ground, if this is not taken into account in the converter design. This paper presents a dc/dc boost converter integrated with a full-bridge inverter. The integration of these two stages reduces the ground leakage current. The neutral line of the grid is directly connected to the negative terminal of the PV array, eliminating any possibility of leakage current in this terminal. The principle of operation of the transformerless converter is analyzed, and a 200-W topology is experimentally tested.

Leakage current is one of the main issues for transformerless grid-connected photovoltaic (PV) inverters, and its reduction is a primary focus of various studies reported in the literature. This paper proposes and validates a finite control set model predictive controller (FCS-MPC) with a novel cost function (CF) to mitigate leakage current in a single-phase full-bridge (FB) grid-connected inverter with an LCL filter, making no modifications to the traditional FB topology and without adding any extra components. Furthermore, mathematical modeling is based on the fully actuated system (FAS) model, allowing a reduction in the number of variables sensed during implementation, resulting in only grid current and voltage being measured.

In this paper, a di/dt detection circuit for DC breaker applications is proposed to provide faster short-circuit and overcurrent fault detection, where DC breakers are required to be designed for unidirectional fault current conditions, which is a challenge regarding DC microgrid applications due to some associated problems such as long periods of fault interruption, complex circuit structure, and low reliability. The proposal, which is based on measurement of di/dt, can detect fault current conditions for different distances from the point of failure, and is suitable to operation in both islanding and grid-connected conditions. The proposed circuit was studied theoretically and experimentally in steady state, as well as under load changes and short circuit conditions to ensure proper operation, making this solution a fast current fault detection solution, which is a significant advantage and requirement in DC microgrid applications.

The modern electric power systems are going through a revolutionary change due the development of DC loads and higher efficiency of DC systems where DC microgrids have some attractive characteristics, however they have several challenges such as limiting and interrupting fault current. In this paper, a protection for DC systems based on transient di/dt detection is proposed to provide faster short-circuit and overcurrent fault detection, where DC breakers are required to be designed for bidirectional fault current conditions, which is a challenge regarding DC microgrid applications due to some associated problems such as long periods of fault interruption, complex circuit structure, and low reliability. The proposal can detect fault current conditions for different distances from the point of failure, and is suitable to operation in both islanding and grid connected conditions. The proposed circuit was analyzed theoretically and experimentally in steady state, as well as under load changes and short circuit conditions to ensure proper operation, making this solution a suitable fast current fault DC breaker solution, which is a significant advantage and requirement in protection of DC systems.

Lithium-ion battery management systems (BMSs) for electric vehicles (EVs) require equivalent circuit models (ECMs) that balance prediction accuracy with identifiability, validation robustness, sensing requirements, and embedded computational cost. This PRISMA 2020-oriented systematic review evaluates recent ECM evidence for EV-oriented BMS applications and develops a function-driven model-selection framework. Scopus and Web of Science were searched using database-specific 2020–2025 publication-year filters. Of 721 identified records, 497 were unique, 478 full texts were retrieved, and 256 studies were included; 230 were original research studies and 26 were reviews. Among the 230 original research studies, experimental evidence was documented in 219 (95.2%), whereas 89 (38.7%) were rated sufficient for validation-data independence. These results show that terminal-voltage accuracy alone is insufficient to establish ECM deployability. The review therefore introduces a minimum-sufficient-complexity framework that links the target BMS function to model structure, parameterization, validation evidence, available sensors, and computational constraints. The resulting guidance supports selection of the least complex ECM that is both physically relevant to the target BMS decision and adequately identifiable and validated.

This paper reviews intelligent battery charging strategies for Society 5.0 and their relevance to electric vehicles, microgrids, and energy storage systems. Conventional and advanced charging methods are discussed, together with the role of state estimation, adaptive control, optimization, and artificial intelligence. The analysis shows that intelligent charging can improve efficiency, safety, battery lifetime, and sustainability. Key challenges and research opportunities are also identified for the development of smarter, more user-centered battery charging systems.