This paper presents the comprehensive design, analytical modeling, and simulation validation of a dual active bridge (DAB) converter for bidirectional power interfaces in microgrid applications. The proposed analysis is developed under single phase shift (SPS) modulation and is based on the voltage applied across the leakage inductance of the high-frequency transformer (HFT), from which the interval-by-interval evolution of the current is derived. This formulation allows the main electric variables of the HFT to be obtained analytically, including the transferred power, average output current, output power, and RMS current stress. The proposed sizing procedure also considers different operating cases according to the power flow direction and the voltage relation between the high- and low-voltage (HV and LV) DC buses. Particular attention is given to the sizing of the DC bus capacitors, whose capacitance and RMS current requirements are determined based on charge variation and the allowable voltage ripple. The analytical results are validated using a PSIM simulation model under both HV-to-LV and LV-to-HV power flow, including operation under a significant voltage mismatch condition. In addition, calculated and simulated results are reported for all four operating cases, demonstrating good agreement between the analytical formulation and the converter’s simulated behavior.

DC Power Grids (DCPGs) are becoming more important, mostly due to the inherent DC characterization of new sources and load technologies, like renewables and electric vehicles. Remarkably, thanks to advances in power electronics converters and control algorithms, bipolar DCPGs are attaining additional prevalence, which results mainly from the increasing efficiency and power density of power converters, but also because DCPG avoid some characteristic power quality problems of the AC power systems. The voltages of the bipolar DCPG should be balanced in the main source by the AC-DC power converter, or by additional converters with the single objective of voltage balancing; however, independently of the voltage balancing and depending on the loads, which can be linked through two-wires or three-wires, current unbalances may occur. In this context, this paper proposes a novel three-wire DC-DC converter operating as an Active Balancer of Currents (ABC), which is linked in parallel to the bipolar DCPG through the three-wires of the point of common coupling (PCC), to ensure balanced currents in the main source. The proposed three-wire DC-DC converter operating as an ABC has a three-wire interface and offers the possibility of a bidirectional power operation, ensuring the compensation of all scenarios of current unbalances. Since it is linked in parallel to the bipolar DCPG, it controls and balances directly the current between wires, ensuring balanced currents on the source side and zero current on the neutral wire. A laboratory prototype was developed and experimental results were obtained. The validation was carried out considering distinctive current unbalances, both positive and negative, as well as sudden variations, verifying the correct operation of the proposed three-wire DC-DC converter functioning as an ABC.

The growing incorporation of distributed energy resources (DER) in power distribution grids, although pivotal to the energy transition, increases operational variability and amplifies the exposure to disturbances that can compromise resilience and the continuity of service during contingencies. Addressing these challenges requires both a shift toward flexible distribution architectures and the adoption of advanced power electronics interfacing systems. In this setting, this paper proposes a resilience-oriented strategy for medium-voltage (MV) distribution systems and clustered hybrid AC/DC microgrids interfaced through solid-state transformers (SSTs). When a fault occurs along an MV feeder segment, the affected microgrids naturally transition to islanded operation. However, once their local generation and storage become insufficient to sustain autonomous operation, the proposed framework reconfigures the power routing within the cluster by activating an emergency low-voltage DC (LVDC) power path that bypasses the faulted MV section. This mechanism enables controlled power sharing between microgrids during prolonged MV outages, ensuring the supply of priority loads without oversizing SSTs or reinforcing existing infrastructure. Experimental validation on a reduced-scale SST prototype demonstrates stable grid-forming and grid-following operation. The reliability of the proposed scheme is supported by both steady-state and transient experimental results, confirming accurate voltage regulation, balanced sinusoidal waveforms, and low current tracking errors. All tests were conducted at a switching frequency of 50 kHz, highlighting the robustness of the proposed architecture under dynamic operation.

Conventional power grid infrastructures, marked by rigidity and technological obsolescence, struggle to meet the demands of modern power systems. Furthermore, low-frequency transformers (LFT) lack controllability and multifunctional capability, while their operational lifetime reduces under the widespread use of nonlinear loads. Thus, achieving stable operation requires advanced power electronics converters and a shift towards hybrid AC/DC smart grids, both at the medium-voltage (MV) distribution level and within low-voltage (LV) microgrids. To address these goals, this article proposes a multiterminal solid-state transformer (SST) for MV/LV power routing. As a distinguishing feature, it integrates an isolated DC/DC quad-active bridge (QAB) converter as the intermediate power stage, unifying and providing complete galvanic isolation among four electrical ports: 1) MVAC; 2) MVDC; 3) LVAC; and 4) LVDC. A downscaled SiC-based prototype, switching at 50 kHz, experimentally validates the concept. Explicitly, tests on the QAB stage under distinct power flow scenarios confirm the feasibility of the proposed SST, establishing it as a promising solution in hybrid AC/DC smart grids.

In recent years, the demand for more sustainable and energy-efficient mobility solutions has accelerated the development of electric vehicles (EVs) and their charging infrastructure. This paper proposes a customized high-frequency planar transformer (HFPT) for integration into an LLC resonant converter intended for EV fast-charging applications. The main contribution of this work is the design and optimization of the HFPT based on a modular segmented ferrite core structure composed of top and bottom tiles, side bars, and a central core piece. When assembled, these components form a compact planar magnetic structure suitable for high-power LLC converter applications. The LLC converter is designed to support a wide input voltage range of 550 V to 800 V and an output voltage range of 240 V to 460 V. The HFPT design methodology carefully considers the effects of the segmented core structure, including magnetizing and leakage inductances, flux density distribution, core and winding losses, and parasitic capacitances. The magnetic design was validated through finite element method (FEM) electromagnetic simulations performed in ANSYS Maxwell. The overall converter performance was analyzed in PSIM and subsequently verified through the implementation of a 10 kW laboratory prototype. Experimental results were obtained for a 3 kW prototype, confirming zero-voltage and zero-current switching (ZVZCS) over the entire tested output power and voltage ranges. The prototype achieved a maximum efficiency of 96.1%, with a flat efficiency curve maintained across the full tested operating voltage range, demonstrating that the customized HFPT is a practical, scalable, and cost-effective solution for high-power EV fast-charging applications.

Wide-bandgap (WBG) semiconductor materials such as silicon carbide (SiC) and gallium nitride (GaN) are key enablers of power-electronics converters for aerospace platforms, where high efficiency, weight reduction, and thermal robustness are critical requirements. This paper presents the main challenges associated with the use of these technologies, including protection requirements, electromagnetic compatibility, and thermal management, as well as the material advantages that enable higher switching frequencies and lower losses compared to conventional Si technologies. A comparative analysis of semiconductor technologies and suitable power-conversion topologies for the aerospace context is provided. Representative laboratory-scale experimental validation is presented, including the development of a DC–DC boost converter and a DC–AC full-bridge inverter, which are linked through the common DC-link and are used for interfacing batteries and an electrical motor, both based on GaN and SiC diodes. The results demonstrated the correct operation, with stable high-frequency performance under controlled laboratory conditions, supporting aerospace-oriented development, although evaluated in a laboratory environment, confirming the potential of WBG technologies for future power-conversion architectures.

The rapid adoption of electric vehicles (EVs) has increased the demand for high-power EV fast-charging converters, intensifying thermal stress on discrete power semiconductors such as silicon carbide (SiC) MOSFETs and diodes. Efficient thermal management is therefore crucial for maintaining device reliability, particularly at high switching frequencies and high-power densities. This paper presents a comprehensive thermal optimization framework for integrating vapor chambers into high-power EV fast-charging converters. Using the Wolfspeed CRD-60DD12N-K 60 kW LLC resonant converter as a reference, the baseline thermal behavior is characterized through COMSOL Multiphysics simulations of a forced air-cooled heat sink. A multiphysics model is developed to incorporate a copper-water-vapor chamber, accounting for wick porosity, laminar vapor flow, and phase-change heat transfer. Thermal performance enhancements are demonstrated through experimental benchmarking, with vapor chamber integration reducing peak device temperatures by over 39 % and significantly improving temperature uniformity. An optimization algorithm is implemented in MATLAB to minimize the dimensions of the vapor chamber and heat sink while satisfying heat-transfer limitations imposed by capillary, boiling, viscous, sonic, and entrainment constraints. The validated simulation model demonstrates the potential to reduce the vapor chamber footprint by 41.8 % and the heat-sink area by 34 % without compromising thermal reliability. These findings establish the viability of compact, high-efficiency vapor-chamber-assisted thermal solutions for next-generation high-power EV fast-charging converters.

Efficient thermal management is essential to ensure reliability and performance in high-power electric vehicle (EV) fast-charging converters employing silicon carbide (SiC) MOSFETs. SiC MOSFETs are widely adopted in next-generation power converters due to their high efficiency, fast switching capability, and ability to operate at high temperatures. This paper presents an integrated thermal management strategy combining a copper-inlay printed circuit board (PCB) with a hybrid aluminum cold plate containing embedded copper pipes to improve heat spreading and SiC MOSFET die-to-coolant thermal performance. A complete analytical and simulation-based framework is developed to evaluate the thermal resistance of each layer in the conduction path, starting with the SiC MOSFET die, then the solder joint, copper inlay, thermal interface material (TIM), and cold plate, and finally the circulating coolant. The power-loss profiles of the SiC MOSFETs and diodes were calculated using analytical switching-loss and conduction loss models. Finite-element simulations in COMSOL Multiphysics quantify the internal temperature distribution and evaluate the impact of PCB configuration, TIM conductivity, and coolant flow rate on the SiC MOSFET die and package surface temperature. Results show that the copper-inlay PCB reduces thermal resistance by more than 30 percent compared to via-based boards, lowering the MOSFET package surface temperature from approximately 130 degrees C to 102 degrees C under identical power dissipation. Parametric analysis demonstrates that selecting an optimized TIM conductivity of 5 W/(m & centerdot;K) and a coolant flow rate of 1 GPM reduces the SiC MOSFET die temperature from 102 degrees C to about 41 degrees C. Experimental validation using a fabricated prototype showed strong correlation with simulation results in terms of spatial temperature distribution and hotspot locations, confirming the accuracy of the thermal model. The proposed multilayer copper-inlay and cold-plate configuration provides a compact, reliable, and scalable thermal solution for next-generation SiC-based high-power EV fast-charging converters.

Active rectifiers are of paramount importance for guaranteeing power quality in smart grids, due to their characteristics of sinusoidal current consumption and unitary power factor operation. In this paper, a novel unified single-phase (USP) front-end converter is proposed for active rectifier applications in smart grids, offering additional advantages and a set of relevant features besides the conventional active rectification. With the proposed USP front-end converter, the following independent operation modes are available: 1) operation as a traditional active rectifier, ensuring sinusoidal AC grid current (with very low total harmonic distortion), unitary power factor, and controlled DC link voltage; 2) operation as a shunt active power filter, producing a current with controlled harmonic content and phase angle at the fundamental frequency, in order to ensure almost sinusoidal current and a unitary power factor at the AC power grid; and 3) combined operation as an active rectifier and as a shunt active power filter, providing power to the DC load, while simultaneously producing a current waveform with reduced harmonic content and controlled power factor. By controlling these individual operation modes, electrical appliances in smart grids can operate dynamically and collaboratively, improving power quality. In addition, the proposed USP front end converter may operate as a single-phase diode rectifier in case of control system failure or damage of the controlled switching devices. This situation is particularly relevant since it allows to supply the DC load even under such unfortunate circumstances. Along with the paper, the topology of the proposed USP front end converter, its principle of operation, and the control strategies for each operation mode, are separately explained. A 3.6 kW, 230 V-50 Hz laboratorial prototype of the proposed USP front end converter is presented, and the experimental validation is carried out for all operation modes.

DC-DC converters are fundamental to electric vehicle (EV) fast charging infrastructures, where the LLC DC-DC resonant converter is widely adopted due to its soft-switching capability, high efficiency, galvanic isolation, and wide output voltage regulation. The high-frequency transformer in the LLC converter plays a key role in achieving such features, as well as for ensuring high power density. This study presents the design of a planar transformer that incorporates detailed modeling of critical parameters, including magnetizing and leakage inductance, flux density, losses, and parasitic capacitances. A custom ferrite core structure is proposed, consisting of ferrite tiles, ferrite bars, and a central ferrite block for a 25 kW LLC converter power module operating with an input voltage range of 650 V to 850 V and an output voltage varying between 200 V and 500 V. The proposed design was validated through electromagnetic simulations in ANSYS Maxwell, employing the finite element method (FEM), while the performance of the LLC converter was analyzed using PLECS simulations.

The dependence of power electronics converters is increasingly unquestionable, where a vast majority of topologies can be used supported by digital control algorithms. Normally, control requires the use of sensors, however, although less considered, sensorless techniques can also be applied, offering the possibility of reducing the hardware necessities, while increasing the control requirements. This paper proposes a sensorless current control applied to a DC-DC buck converter. The mathematical formulation of the sensorless technique is presented for contextualization with the DC-DC buck converter but, it is also illustrated how it can be derived for other voltage-source converters, controlled by current. The validation is performed by computer validation and corroborated by experimental results of a fully developed laboratorial prototype of a DC-DC buck converter. The results confirm the applicability of the proposed sensorless current control for different requirements of load operation.

In electric railway trains two main power systems can be distinguished: The system of the power propulsion and the system of the auxiliary power services. Consequently, since the train is supplied from the catenary in AC, the use of an AC to DC power converter is indispensable. This paper proposes the application of a modular multilevel converter (MMC) as main power converter (i.e., interfacing the AC catenary and the DC link inside the train). The operation of the MMC is ensured by a model predictive current controller, which controls its input AC current according to specific power requirements. The MMC and the model predictive current control are validated recurring to computer simulations. Based on the developed simulation models, the presented results permit to verify the advantages associated with the modularity of the converter and with the performance of the model predictive current control.

Hand to hand with the ongoing energy transition, this paper proposes a conceptual multibus architecture for smart homes, designed to improve flexibility, efficiency, and scalability of residential DC microgrids. The proposed solution centralizes DC distribution at 800 V-DC using the first conversion stage of a solid-state transformer (SST), while the subsequent two stages are allocated at the smart home level. In this context, four SST-based schemes are introduced to implement a residential multibus comprising 400 V-DC, 48 V-DC, and 230 V-AC voltage feeders, tailored to meet the requirements of modern and future applications. This approach aims to minimize conversion losses, improve power quality, and ensure robust power supply across the residential system. The suggested concept supports seamless integration of DC-native systems, enabling adaptability to the dynamic nature of residential loads and fostering the incorporation of emerging technologies within smart homes and smart grids.

This paper explores the transformative role of solid-state transformers (SSTs) in enhancing the performance of smart grids and microgrids, focusing on their technological capabilities and contribution to sustainability. Renowned for their flexibility, adaptability, and scalability, SSTs are crucial for improving the resilience of electrical systems, particularly in dynamic infrastructures with multiple loads and renewable energy sources (RES). Key features, such as seamless transitions between grid-connected and island modes, position SSTs as pivotal elements in addressing the challenges posed by the ongoing energy transition. By dynamically mitigating faults and improving power quality, SSTs ensure reliable supply during power outages and disturbances. Computational simulations validate SST's effectiveness in power flow management, reinforcing their capability to optimize power grid stability under both steady and transient states. Thus, this paper highlights how SSTs bridge technical feasibility with sustainability principles, empowering the integration of emerging technologies while strengthening power grid controllability. The integration of grid-following and grid-forming capabilities further ranks SSTs as catalysts for modern power systems, offering significant technological and societal benefits. These characteristics are particularly valuable in regions with limited access to reliable electricity, where SSTs, combined with distributed generation, can promote energy security, economic development, community engagement, and social equity.

This paper proposes a novel single-phase integrated inverter for photovoltaic (PV) applications called Hybrid Inverter Zeta-Cuk (HIZC). The HIZC operates in discontinuous conduction mode and employs four unidirectional power switches, which are achieved by associating series power diodes to MOSFETs. In addition, during the grid's positive half-cycle, the inverter acts similarly to the Zeta converter. On the other hand, during the negative half-cycle, the inverter operates similarly to the Cuk converter. Due to the adopted design criteria, the Zeta and the Cuk operation modes show similar behavior. The small-signals analysis considers the Zeta and Cuk operation modes, showing a significant similarity between their frequency responses, proofing the similarity of the HIZC's functionality in both operation modes. The HIZC can boost the voltage of the PV array and perform the DC-AC conversion at the same time. The maximum power available at the PV array is harvested using a multi-loop control in conjunction with the perturb-and-observe algorithm, while an AF-alpha beta-PLL system guarantees synchronism with the power grid. Experimental results prove the structure feasibility of the proposed topology for PV applications. In addition, the HIZC presents high-efficiency conversion and also low total harmonic distortion in the current injected into the power grid.

This paper presents a high-efficiency wireless power transfer (WPT) architecture employing a resonant inductive coupling to power smart sensor nodes in remote or sealed environments, where conventional power delivery is unfeasible. The system integrates a photovoltaic (PV) energy source with a step-down DC-DC converter based on the LM2596 buck regulator to adjust the voltage from the PV. The proposed conditioned power system supplies the entire electronic circuit consisting of a PWM modulator based on an NE555, which drives an IR2110 gate driver connected to a Class D power amplifier. The amplifier excites a pair of high-Q resonant coils designed for mid-range inductive coupling. On the receiver side, the inductively coupled AC signal is rectified and regulated through an AC-DC conversion stage to charge a secondary energy storage unit. The design eliminates the need for physical electrical connections, ensuring efficient, contactless energy transfer. The proposed system operates at a resonant frequency of 24.46 kHz and achieves up to 80% transmission efficiency at a distance of 113 mm. The receiver provides a regulated DC output between 4.80 V and 4.97 V, sufficient to power low-consumption smart sensors.

In response to the growing demand for technological solutions aimed at enhancing the stability of electrical power systems, this paper proposes a new approach to power flow management in solid-state transformers (SST). Within the context of smart grids, the increasing integration of renewable energy sources (RES) introduces greater uncertainty and variability, making it critical to balance mismatched generation and consumption periods. This study explores the integration of batteries into the core of the SST architecture, targeting power grid stabilization and galvanic isolation between the medium-voltage (MV) and low-voltage (LV) subsystems. To this end, a triple active bridge (TAB) converter is used in the SST’s isolated stage, offering enhanced flexibility and resilience by enabling energy storage and demand-driven power routing. Computational simulations validate the proposed multiport DC-DC converter, which employs a dual-phase shift (DPS) modulation to control both the direction and magnitude of the power flow. The results confirm the approach’s compatibility with modern electrical power systems, addressing the main challenges and opportunities.

In the high-performance environment of Formula Student Car racing, effective battery thermal management is crucial for safety, reliability, and performance. This work presents the design and validation of a lightweight, air-based Battery Cooling System (BCS) developed for a Formula Student vehicle. The system addresses the significant thermal loads generated by 528 Molicel P45B lithium-ion cells, arranged in a constrained U-shaped module layout. Using Computational Fluid Dynamics (CFD), the airflow geometry was optimized to deliver uniform cooling across all modules while minimizing aerodynamic drag. Simulations evaluated the system’s performance under various ambient temperatures (25 °C and 30 °C) and airflow velocities (from 16 m/s to 18 m/s), identifying the impact of duct geometry, internal air guides, and airflow distribution on thermal regulation. Results showed that, at nominal ambient temperature (25 °C), all monitored cells stayed below the 60 °C threshold required by FS regulations. At elevated ambient conditions (30 °C), regions above 60 °C appeared within the pack, revealing non-uniform cooling and reduced safety margin. These findings suggest that, while the system complies with current rules, additional design refinements are needed to enhance robustness under harsher conditions. Additionally, these results are specific to a Formula Student application under competition constraints and are not intended to be generalized to production EVs.

Power quality is a concern and more and more relevant due to the numerous technologies requiring an interface with the power grid through power electronics converters. Thus, efficient power factor correction (PFC) circuits, ensuring unitary power factor, sinusoidal AC currents, and controlled DC voltages, are of utmost importance. Aligned with such importance, a novel Single-phase Interleaved-based Three-level (SIT) PFC rectifier is proposed in this paper, which can be used in various applications for AC-DC conversion. A thorough explanation of the SIT PFC rectifier is given, supported by a comparison with the traditional solutions. Additionally, a predictive-based current control is discussed. The obtained simulations permit to examine the complete operation principle of the SIT PFC rectifier (i.e., sinusoidal AC current, interleaved-based mode, three levels of voltage, controlled DC voltage), revealing its accuracy even when operating in critical conditions of operation.

YThis paper introduces an LLC converter with a variable input DC-link voltage, aimed to address the challenges of single stage DC-DC converter with wide output voltage range associated with electric vehicle (EV) fast chargers. The proposed design optimizes the input/output voltage ratio to enhance efficiency across a wide range of charging operating power values. The analysis highlights the converter's ability to accommodate the output voltage range from 200 V to 500 V with input voltage variations from 650 V to 850 V, while operating at frequencies between 73 kHz and 114 kHz for power levels up to 25 kW. With efficiency range from 97.5% to 98.5%, this design offers a highly efficient and adaptable solution for EV fast chargers, aligned with the technical requirements and performance expectations of modern EV charging infrastructures.