Search Results (179)

The increasing adoption of electric vehicles (EVs) demands highly efficient bidirectional DC–DC converters capable of seamless energy transfer between the grid and vehicle batteries. This paper introduces a Fixed-Frequency Dual-Active-Bridge (DAB) resonant converter featuring four degrees of freedom, achieved through a combination of triple phase-shift (TPS) modulation and a current-controlled variable inductor (VI). The proposed control strategy aims to minimize conduction and switching losses by simultaneously managing reactive power, RMS current, and soft-switching conditions across wide variations in voltage and power. Unlike conventional phase-shift or variable-frequency modulations, the fixed-frequency operation maintains full zero-voltage switching (ZVS) for the two bridges, and zero-current switching (ZCS) in the bridge that is receiving energy, enhancing overall system reliability and control simplicity. The proposed converter is validated through simulations and experimental results from a SiC MOSFET-based 14 kW prototype operating at 122 kHz, demonstrating peak efficiencies above 97% under both charging and discharging modes. The experimental results confirm that the proposed DAB topology and modulation scheme significantly improve efficiency and controllability, making it a promising solution for next-generation on-board chargers and vehicle-to-grid (V2G) applications. Full article

Ultra-fast electric vehicle (EV) charging systems are among the most demanding converter-dominated applications due to their high power levels, wide battery-voltage range, strict thermal constraints, and the need for adaptive charging control. Conventional design and tuning approaches often rely on fixed control policies and computationally expensive iterative optimization, which limits their ability to address nonlinear multi-objective trade-offs across the full charging envelope. This paper proposes a hybrid AI–quantum co-design framework for a SiC-based dual active bridge (DAB) converter intended for ultra-fast EV charging applications. The proposed approach combines a physical converter model, an AI surrogate-learning layer for rapid prediction of converter performance, and a quantum-assisted optimization layer for multi-objective exploration of design and control variables. To demonstrate the framework, a representative modular 350 kW ultra-fast charging case study is considered, implemented by four parallel 87.5 kW SiC-based DAB modules and including converter-level optimization and adaptive charging-policy refinement. The revised manuscript introduces a complete system schematic, an explicit DAB converter topology, a clarified methodological workflow, and a simulation-based proof-of-concept evaluation. Representative results indicate improved design-space exploration and more balanced trade-offs between efficiency, thermal stress, ripple, and dynamic response compared with a conventional baseline tuning approach. Although the study does not claim hardware-level quantum advantage, it provides a structured and practically interpretable computational framework for intelligent co-design of high-power charging converters. Full article

The dual-active-bridge (DAB) converter is the core component of the DC micro-grid system; it has the advantages of topological structure symmetry, high efficiency, and high-power density. Model predictive control (MPC) is often employed to improve the dynamic response characteristics of the system, but its strong parameter dependence is a key factor limiting the development of MPC. Therefore, a model-free predictive control (MFPC) method combining an ultra-local model with model predictive control is proposed to solve the problem of strong dependence of traditional MPC on system model parameters. Firstly, establish the ultra-local mathematical model of the DAB converter. The system’s lumped disturbances are identified using the residual prediction method and substituted into the discrete model of the system at the next time step to achieve model-free prediction. Secondly, a minimum back-flow power constraint is added to the cost function to improve the steady-state performance of the converter. Thirdly, in the extended phase shift modulation, the Lagrange multiplier method (LMM) is proposed to reduce the current stress, ultimately achieving the collaborative optimization of the comprehensive performance of the DAB. Finally, a simulation model is built using MATLAB/Simulink, and compared with traditional control methods, the voltage ripple has been reduced by 51.3%, 89.1%, and 85.1%, respectively; the current stress significantly decreases both when the output voltage reference value changes and when the load resistance changes abruptly, and both can basically achieve zero back-flow power operation. The validity and superiority of the proposed strategy have been verified. Full article

This paper proposes an optimized variable-frequency phase-shift modulation strategy based on frequency-domain analysis to address the issues of large reactive circulating current and low transmission efficiency in dual-active-bridge (DAB) converters under voltage mismatch conditions. First, a unified frequency-domain analytical model for extended phase-shift (EPS) modulation is established using Fourier series, which avoids the complexity introduced by mode division in traditional time-domain analysis. The Karush–Kuhn–Tucker (KKT) conditions are then utilized to analytically derive the optimal phase-shift angles that minimize the RMS current over the entire power range. Based on this, a control method is proposed to suppress the reactive circulating current by adjusting the switching frequency. Experimental results demonstrate that the proposed strategy significantly reduces the RMS current and reactive circulating current, thereby improving efficiency across a wide voltage gain and full load range, compared to traditional single phase-shift and extended phase-shift strategies. Full article

Hydrogen is a clean energy carrier with broad application potential. This study focuses on improving hydrogen production efficiency in a proton exchange membrane (PEM) electrolyzer system that integrates a photovoltaic (PV) array, a battery energy storage system, and the electrolyzer. The PV array is interfaced with the electrolyzer through a buck converter using a maximum power point tracking (MPPT) algorithm to ensure maximum energy harvesting. A key contribution of this work is the integration of a battery system through a dual-active-bridge (DAB) converter. The DAB converter employs a multilayer perceptron (MLP) model to dynamically regulate the electrolyzer current and maintain optimal operating efficiency. An adaptive energy management strategy is further proposed to address solar irradiance fluctuations and enhance long-term operational stability. The MLP model is developed in Python and embedded into a PLECS simulation environment. The simulation results verify the effectiveness of the proposed control approach and efficiency optimization scheme. Throughout the simulation period, the PEM electrolyzer sustains an optimal efficiency of 69.9% under maximum PV power output. A limitation of this study is that the efficiency model is derived from the literature and does not yet consider all operational factors, indicating the need for refinement in future work. Full article

This study proposes an adaptive variable structure control strategy for charging stacks to address the issues of reduced conversion efficiency during wide-voltage-range operation and insufficient module allocation flexibility in multi-vehicle scenarios. By dynamically adjusting the number and series/parallel configurations of modules, the strategy ensures that modules consistently operate in high-efficiency regions, thereby achieving high energy conversion efficiency across a wide voltage range. First, the operational characteristics of the three-phase PWM rectifier and the dual active bridge (DAB) converters are analyzed, and their corresponding mathematical and loss models are established. Subsequently, the charging demands acquired by the charging stack are analyzed, and an adaptive variable structure control strategy is designed based on the module margin of the charging stack. When modules are surplus, the feasible range of series/parallel configurations for each port is constrained, and module combinations are optimized with the objective of minimizing system losses. When modules are insufficient, an adaptive module reservation scheduling strategy is employed to ensure temporal fairness in vehicle connection order while supplying power to multiple vehicles, effectively reducing the average charging time. Finally, the effectiveness of the proposed control strategy is validated through simulations conducted on the Matlab/Simulink platform. Results demonstrate that compared to traditional fixed-structure systems, the proposed strategy improves peak efficiency by up to 2.53% at 400 V and 1.12% at 800 V, while reducing the average charging time by 3.07% in the disconnection scenario and 12.1% in the asynchronous access scenario. Full article

Although electric vehicles are being vigorously promoted around the world, the mileage anxiety problem is an important hindrance to their development. Thus, this paper proposes an auxiliary half-bridge dual active bridge (AH-DAB) converter between different electric vehicles, which is based on nonlinear virtual power predictive control. For the converter, characteristics of high power density, wide voltage gain range, and high efficiency are necessary. Firstly, an AH-DAB converter is applied to improve the control variable. Under this effect, the converter can switch between the half-bridge and the full-bridge converter. Secondly, a duty ratio design method is proposed to improve zero-voltage switching (ZVS) performance. Therefore, wide voltage gain range, decoupling of control variables, and high efficiency can be achieved in the nonlinear AH-DAB system. Thirdly, the nonlinear virtual power predictive control is proposed to ensure energy transfer between two electric vehicles. Based on this, the phase shift angle can be predicted and adjusted by ensuring that the actual power is consistently maintained close to the reference power. Moreover, the virtual power is generated to represent the reference power, which can reduce the number of current sensors. Finally, simulation and experiment results collectively show the wide voltage gain range and high efficiency of the proposed AH-DAB converter. Full article

The wide voltage range of energy storage batteries, as currently required in the electric vehicle industry, presents significant challenges for the optimal design of the dual active bridge (DAB) converters used in bidirectional DC–DC (BCD) plug-in electric vehicle (PEV) chargers and home energy management systems (HEMS) applications. This article proposes a DAB converter with an enhanced single-phase-shift (ESPS) modulation that extends the operating voltage range while maintaining zero-voltage-switching (ZVS) conditions by including a DC-blocking capacitor and modifying the trigger sequence of the bridge converter on the secondary side. The operational modes of this modulation scheme are presented, and a control strategy is developed to extend the ZVS range. To validate the concept, a 3.7 kW, 100 kHz prototype is designed and tested, interfacing a 400 V DC bus with a 400–800 V battery. Using 1200 V silicon carbide (SiC) devices, the prototype achieves a peak efficiency of 95.5%. Full article

The growing electrification of ports and maritime transport requires flexible power systems capable of supplying multiple voltage levels with high efficiency and power quality. Battery-based power barges offer a promising solution, but their power conversion systems must handle wide voltage and power ranges while remaining stable under dynamic operating conditions. This paper presents a scalable multi-stage power conversion architecture for battery-based power barges that can supply both low-voltage and high-voltage AC loads from a common DC source. The system combines isolated Dual Active Bridge (DAB) DC–DC converters with a three-level Neutral-Point-Clamped (NPC) inverter. An input-parallel output-series DAB configuration is used for high-voltage operation, enabling modularity and scalability within semiconductor limits. A coordinated control strategy ensures stable DC-link regulation, balanced module operation, and high-quality AC voltage generation. Simulation results confirm stable operation, fast dynamic response, a voltage THD below 4%, and overall efficiency above 95%, demonstrating the suitability of the proposed architecture for future power barge and port electrification applications. Full article

To address the issues of excessive current stress and the power dead zone associated with conventional phase-shift modulation in dual-active-bridge (DAB) converters, a hybrid optimized modulation strategy based on dual-side asymmetric duty modulation (ADM) is proposed. The proposed strategy aims to minimize the peak-to-peak current stress by introducing two distinct operating modes of the converter. A dynamic compensation mechanism based on mode switching is developed, enabling a coordinated dual-mode modulation to achieve minimum peak-to-peak current stress over the full power operating range. In addition, a virtual voltage control scheme is incorporated to enhance the dynamic response and stability of the system. Finally, experimental results obtained from a laboratory prototype verify that the proposed strategy effectively reduces the peak-to-peak current stress while significantly improving the dynamic performance of the DAB converter. Full article

To address the issues of significant dc bus voltage and load fluctuations, as well as unstable power transmission in dual active bridge (DAB) converters within dc microgrid systems, this article proposes a segmented gain adjustment method based on multiplicative feedforward control (MFC-SGA). First, considering both steady-state and dynamic performance of DAB converters, two hybrid optimization control methods are proposed, and their advantages and disadvantages in terms of circuit parameter sensitivity and controller gain are analyzed. Second, to overcome the limitation of multiplicative feedforward control in light-load conditions due to restricted controller gain, the MFC-SGA method is introduced to enable adaptive parameter adjustment. Finally, an experimental prototype is built. Experimental results show that the MFC-SGA method is independent of inductance accuracy. When the operating condition changes, compared with the traditional method, the settling time is shortened by 60–83% and the overshoot is reduced by 37.5–62.5%; especially in light-load mode (10% of rated current), the dynamic response speed is improved by 68.75% compared with the MFC method, and the settling time is reduced from 32 ms to 10 ms. The experimental results verify the feasibility and effectiveness of the proposed method. Full article

In microgrid systems, due to the strong intermittency and randomness exhibited by solar energy and wind energy, significant challenges are posed to the stable power supply and normal operation of actuators. Thus, bidirectional DC-DC converters are required to possess excellent steady-state characteristics and dynamic response performance. This paper presents an active disturbance rejection control (ADRC) method for dual active bridge (DAB) converters incorporating current stress optimization, centering on the analysis and investigation of the integrated technique of current stress optimization and ADRC for DAB converters under triple-phase-shift (TPS) control. Based on TPS modulation, the optimal current stress strategies corresponding to different operating modes are deduced. Meanwhile, an ADRC closed-loop is established, where the extended state observer (ESO) performs real-time estimation of system states and compensates for system disturbances. Furthermore, a unified control model is constructed, facilitating flexible trade-off between control complexity and performance. Finally, a simulation scheme is designed to compare the performance of different control schemes, and the simulation results verify the feasibility and superiority of the proposed strategy. Full article

To address the issues of limited soft-switching range and high inductor current peak in traditional single phase shift (SPS) modulation for AC–DC converters under a wide range of voltage conversion ratio conditions, this paper proposes an optimized modulation strategy based on SPS modulation. First, the steady-state operating characteristics under SPS modulation are analyzed, and the current-transfer equation is derived. A conversion coefficient is then introduced to transform the conventional phase-shift ratio into a new variable. Based on this, the time-domain characteristics of the inductor current peak and the constraints for zero voltage switching (ZVS) are analyzed. An analytical expression of the conversion coefficient is obtained, which ensures ZVS operation for all switches in the dual-active-bridge (DAB) converter and minimizes the inductor current peak. Finally, experiments verify the effectiveness and feasibility of the proposed modulation strategy. Full article

This paper proposes a novel 2-transformer (2-Trans)-based integrated on-board charger (OBC) and low-voltage DC/DC converter (LDC) system for electric vehicles. Conventional integrated OBC–LDC systems employing a three-winding transformer suffer from reduced light-load efficiency during standalone LDC operation because core losses dominate when designers size the transformer for high-power operation. In addition, concentrating multiple windings on a single magnetic core limits transformer design flexibility and causes complex magnetic coupling among the windings. To effectively reduce light-load losses and enhance transformer design freedom, this paper introduces a new integrated charging architecture that utilizes two independent transformers. The proposed system adopts a dual-active-bridge (DAB) converter for high-voltage battery charging and a phase-shift full-bridge (PSFB) converter for low-voltage battery charging. The system supports both simultaneous high- and low-voltage battery charging and standalone low-voltage battery operation, and a dual-phase-shift (DPS) control strategy enables independent and proper power flow control. Experimental results obtained from an 11 kW OBC and a 3 kW LDC prototype demonstrate up to a 33% reduction in light-load losses during standalone LDC operation and confirm the feasibility of improving power density through the proposed 2-Trans-based architecture. Full article

Hardware-in-the-loop (HIL) simulation is an essential tool for rapid and cost-effective development and validation of power-electronic systems. The primary objective of this work is to validate and fine-tune a PLECS-based HIL model of a single dual active bridge (DAB) DC-DC converter, thereby laying the foundation for building more complex models (e.g., multiple converters connected in series or parallel). To this end, the converter is experimentally characterized, and the HIL model is validated across a wide range of operating conditions by varying the PWM phase-shift angle, voltage gain, switching frequency, and leakage inductance. Power transfer and efficiency are analyzed to quantify the influence of these parameters on converter performance. These experimental trends provide insight into the optimal modulation range and the dominant loss mechanisms of the DAB under single phase shift (SPS) control. A detailed comparison between HIL simulations and hardware measurements, based on transferred power and efficiency, shows close agreement across all the tested operating points. These results confirm the accuracy and robustness of the proposed HIL model, demonstrate the suitability of the PLECS platform for DAB development and control validation, and support its use as a scalable basis for more complex multi-converter studies, reducing design time and prototyping risk. Full article