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Electric vehicles (EVs) are a sustainable means of transportation, with their onboard batteries being crucial for both performance and energy management. A modular and reconfigurable power converter topology to connect removable batteries to the main DC bus of an EV is proposed in this paper. By employing Dual Active Bridge (DAB) converters in an Input Parallel Output Series (IPOS) configuration, the proposed topology is compatible with 400 V and 800 V standards without the need for external switches. The research explored the possibility to apply a very simple control strategy based on independent linear regulators. A theoretical analysis of the IPOS DAB converter is presented and the design of independent control regulators which minimize the coupling effect between the control variables is addressed. The stability of the IPOS DAB converter could be ensured using the proposed simplistic approach, enabling us to drastically simplify the regulator design step. The dynamic performance of the system was confirmed by means of a simulation and experimentally. [ABSTRACT FROM AUTHOR]

Abstract In recent years, the integration of bidirectional converters in the grid for V2G (vehicle-to–grid) applications of Electric Vehicles (EVs) has gained significant attention due to its potential to enhance grid stability, energy efficiency, and economic benefits. This analytical review highlights the different topologies of bidirectional converters and discusses various control techniques for efficient power flow between the vehicle and grid to enhance the performance of V2G and G2V functionalities. Further, the topologies of bidirectional converters highlighting key parameters such as the count of switches and their voltage stress, current ripple, efficiency, etc., are explored. The distinct advantages and limitations of each classification are also discussed. Many multilevel topologies that generate significant gain with low stress on switches and lesser harmonics have also been reviewed. The review then examines various control strategies, including power flow control and voltage regulation. These techniques are classified according to their control methodologies, which include traditional proportional-integral (PI) control, predictive control, sophisticated model-based control, and optimization. The synthesis of current advances in bidirectional converters and control techniques sheds light on developing trends and technologies, identifying important problems and future research objectives in the field. The economic and environmental implications of the G2V and V2G case studies also reinforce the review. Thus, this evaluation aims to promote further breakthroughs in EV integration with the grid, eventually leading to a more sustainable and resilient energy ecology.

Abstract This paper introduces a novel high-voltage gain topology for a solid-state transformer, integrating a DC-DC converter and dual active bridge converters. The proposed design features three DC links operating at different voltage levels. The first DC link connects to a single-switch high step-up DC-DC converter, while the second DC link interfaces with an AC source via a rectifier, allowing the use of both DC and AC inputs. A high-frequency transformer ensures galvanic isolation between the sources and the third DC link. The DC-DC converter employs coupled inductors and voltage multiplier cells, offering distinct advantages such as a high voltage gain, reduced voltage stress on semiconductors, and minimized current ripple. These features make the topology highly suitable for transferring power from renewable energy sources, such as photovoltaic panels, to a high-voltage DC link in microgrid or nanogrid applications. The novelty lies in the combination of multiple voltage levels, high-frequency isolation, and the ability to handle both DC and AC inputs efficiently. An experimental prototype, delivering 620 W with a 25 V DC input and 110 V AC input, is built, and the results validate the converter’s effectiveness.

ABSTRACT This article deals with the modeling and control of a solid‐state transformer (SST) based on a dual active bridge (DAB) and modular multilevel converter (MMC) for integrating solar photovoltaic (SPV) and battery energy storage (BES) systems into the grid. SST uses DABs for bidirectional DC‐DC conversion and an MMC for DC‐AC conversion. A hybrid control method is developed in this study, which combines proportional‐integral (PI) controllers and model predictive control (MPC) to achieve the multiple objectives of the SST. The DABs' control system uses PI controllers for power extraction from the SPV system and to regulate the charging and discharging of the BES according to power generation and demand fluctuations. MPC is applied to control the active power injection, regulate the DC‐link and sub‐module capacitor voltages of the MMC. Moreover, the developed hybrid control method ensures reliable SST performance even under adverse conditions like grid voltage distortion, unbalance, and frequency variations. An energy management strategy is developed based on total power generation, reference active power injection, and the state of charge of the BES. This strategy ensures accurate reference power injection to the grid despite dynamic changes in operating conditions. The article also presents a detailed mathematical model of the DAB and MMC components, and the stability of the control algorithm is analyzed theoretically. The effectiveness of the SST and the proposed hybrid control scheme is demonstrated through MATLAB/Simulink simulations and hardware‐in‐the‐loop experimental results under various operating conditions. [ABSTRACT FROM AUTHOR]

The publication addresses the dynamic state challenges encountered during development of a dual active bridge (DAB) converter within DC microgrid systems. The conventional startup method is identified as instigating a cascade of unfavorable outcomes, encompassing elevated starting current, transformer current asymmetry, DC voltage distortions, EMI and heightened thermal stress on semiconductor components. Additionally, it necessitates precise calibration of magnetic components and diodes. A proposed remedy to these issues is introduced, involving a control method based on an additional phase shift to modulate the current of the primary H bridge. This novel control methodology is posited as a means to mitigate the aforementioned undesirable effects associated with traditional converter initiation techniques. The research also delves into considerations of a proper design procedure for the converter. Emphasis is placed on integrating the novel control methodology into the design framework in order to effectively address challenges arising during transient states. Validation of the proposed solution is substantiated through a series of laboratory tests, the results of which are comprehensively presented in the article. These tests affirm the efficiency of the system when incorporating the novel control methodology, thereby substantiating its practical utility in mitigating the issues identified during the initiation phase of the DAB converter in DC microgrid systems. [ABSTRACT FROM AUTHOR]

In recent years, the integration of bidirectional converters in the grid for V2G (vehicle-to–grid) applications of Electric Vehicles (EVs) has gained significant attention due to its potential to enhance grid stability, energy efficiency, and economic benefits. This analytical review highlights the different topologies of bidirectional converters and discusses various control techniques for efficient power flow between the vehicle and grid to enhance the performance of V2G and G2V functionalities. Further, the topologies of bidirectional converters highlighting key parameters such as the count of switches and their voltage stress, current ripple, efficiency, etc., are explored. The distinct advantages and limitations of each classification are also discussed. Many multilevel topologies that generate significant gain with low stress on switches and lesser harmonics have also been reviewed. The review then examines various control strategies, including power flow control and voltage regulation. These techniques are classified according to their control methodologies, which include traditional proportional-integral (PI) control, predictive control, sophisticated model-based control, and optimization. The synthesis of current advances in bidirectional converters and control techniques sheds light on developing trends and technologies, identifying important problems and future research objectives in the field. The economic and environmental implications of the G2V and V2G case studies also reinforce the review. Thus, this evaluation aims to promote further breakthroughs in EV integration with the grid, eventually leading to a more sustainable and resilient energy ecology.Article highlights: The key points of the paper are: Different converter topologies for G2V & V2G and their impact on the grid are discussed and compared. A critical analysis of state of art control methodologies applied to DC/DC converters has been discussed. Advanced optimization algorithms for smart and coordinated charging of an EV are presented. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) are rapidly replacing fossil-fuel-powered vehicles, creating a need for a fast-charging infrastructure that is crucial for their widespread adoption. This research addresses this challenge by improving the control of dual active bridge converters, a popular choice for high-power EV charging stations. A critical issue in EV battery charging is the smooth transition between charging stages (constant current and constant voltage) which can disrupt converter performance. This work proposes a novel feedforward control method using a combination of droop-based techniques combined with a sophisticated linear active disturbance rejection control system applied to a single-phase shift-modulated dual active bridge. This combination ensures a seamless transition between charging stages and enhances the robustness of the system against fluctuations in both input voltage and load. Numerical simulations using MATLAB/Simulink R2024a demonstrated that this approach not only enables smooth charging but also reduces the peak input converter current, allowing for the use of lower-rated components in the converter design. This translates to potentially lower costs for building these essential charging stations and faster adoption of EVs. [ABSTRACT FROM AUTHOR]

Renewable energy sources (RESs) have become a prominent trend in the development of energy systems in many countries. To manage RESs, microgrids have emerged as an efficient and optimal solution. However, a microgrid might occasionally have problems like overloading and voltage sag. To address this problem, this paper proposes a technique that combines a consensus algorithm and a dual active bridge (DAB) to transfer energy between two different microgrids. A detection technique for overloading and voltage sag is part of the proposed control approach. In these circumstances, the DAB facilitates consensus adjustments to the stable microgrid current to bring it into balance with the overloaded current. By applying this proposed control method, voltage drops are significantly reduced, leading to an improvement in the power system quality. The simulation results of the microgrid and a scaled‐down laboratory system are conducted to verify the feasibility of the proposed control scheme. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This paper presents the effect of dead time on active power transfer of the dual active bridge (DAB) and a novel mitigation technique for the same. The whole power range is categorized into five zones based on the switching instant link current direction and the modified active power expressions with effect of dead time are derived for each zone. The novel compensation method for dead time improves the performance of any general optimized techniques for DAB with extended phase shift. Firstly, the link current values at different switching instants are estimated using the mathematical expressions obtained using a linear piece-wise method. Secondly, the values are used for compensation logic formulation in the whole power range. The compensation process is applied to two different configurations, open loop (circulating mode) and close loop (voltage control mode). The mid-power zone is compensated using a constant phase shift modification and the low power zone is compensated using a PI controller based phase shift modification. Finally, the effectiveness of the proposed compensation technique is verified through MATLAB Simulink model and 1.2 kW experimental prototype. [ABSTRACT FROM AUTHOR]

This paper focuses on the integration technology of electric vehicle motor driving system and on-board charging system. The front-stage bi-directional AC/DC converter time-multiplexes a three-phase bridge full-control circuit into a staggered parallel totem pole power factor correction circuit and a three-phase inverter circuit, which enables the on-board charging system to have a motor control function. It can form a bidirectional AC/DC converter which can realize the function of motor control. The rear-stage DC/DC converter can realize the energy exchange between power supply and power battery or power battery and motor through dual active bridge structure. The working characteristics of the front-stage circuit and the soft switching range of the rear-stage circuit are studied. The mathematical model of the front-stage circuit and the rear-stage circuit are established by small signal analysis, and the control strategy of the front-stage double-closed loop and the rear-stage double-loop competition is adopted. The PI controller parameters are designed by using the mathematical model of the system, and the stability of the compensated system is verified by the open-loop amplitude-frequency characteristic curve. The simulation model and experimental platform are established. The charging mode is verified by the electronic load and high voltage DC source simulate the power battery. The driving mode is verified by using the 5 kW permanent magnet synchronous motor. The simulation and experimental results verify the feasibility of the system to achieve charging and driving functions. [ABSTRACT FROM AUTHOR]

This paper proposes a novel feedforward control scheme to achieve a very smooth transition from Constant Current (CC) to Constant Voltage (CV) charging modes, the commonly used method for electric vehicle charging applications. Furthermore, a three-loop model-independent Linear Active Disturbance Rejection Control (LADRC)-based system is proposed, replacing the traditional two-loop Proportional-Integral (PI) control system. The extra loop performs a decoupled dq vector control of the inductor current, which is typically not used in single-phase Dual Active Bridge (DAB) systems. This additional loop not only facilitates the optimal determination of both internal and external phase shift angles of a Dual-Phase Shift (DPS) modulator but also lowers the peak input current of the converter, allowing for lower-rated switches. Numerical simulations using MATLAB/Simulink demonstrate the robustness of the proposed control strategy against both input voltage disturbances and load disturbances during the transition from CC to CV charging modes. Hence, the dynamic performance of the charging system is significantly improved with minimal controller effort. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Electronic Measurement & Instrument is the property of Journal of Electronic Measurement & Instrumentation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

DC fast charging is critical for the widespread adoption of electric vehicles (EVs) due to its impact on convenience, economics, and environmental sustainability. Due to the critical role of DC fast charging in EV adoption, improving its efficiency and performance is paramount. This paper presents a Fractional-Order PI (FOPI) controller for obtaining a well-regulated output voltage of a Dual Active Bridge (DAB) converter, a widely used topology in EV applications. The proposed FOPI is validated to the conventional PI controller in a simulated DAB model that is relevant to DC fast charging applications. The evaluation is performed, and various time-domain parameters and performance indices to evaluate the dynamic response of the model are considered. The results are expected to demonstrate significant improvement in the converter's transient and steady-state response using the proposed FOPI controller compared to the conventional PI controller, contributing to a more efficient and robust DC fast charging system. This improvement can translate to faster charging times, better stability, and potentially reduced stress on the EV battery during DC fast charging. [ABSTRACT FROM AUTHOR]

The single-phase dual active bridge (DAB) DC/DC converter is a vital component in modern power electronics systems, facilitating efficient bidirectional power transfer between various energy sources and loads. One of the critical aspects in the design of such converters is the selection of an appropriate leakage inductance, as it significantly affects the circulating power within the converter. This study investigates the influence of inductance on the reactive power flow and introduces an analytical formula for calculating the necessary leakage inductance based on the specified rated power of the DAB converter. By employing the inductance values determined through the proposed formula, the developed power control-based modulation method, implemented in discrete time, successfully achieves zero reactive power caused by the first harmonic components under all load conditions. This selection of leakage inductance optimizes the performance of the converter ensuring efficient power delivery across various applications. The applicability of this method extends to various DAB applications, including electric vehicles, integration with asynchronous microgrids, and aerospace systems. [ABSTRACT FROM AUTHOR]

Energy exchange between AC grid and DC supply that is a part of a hybrid electric micro-grid takes place using various power converter designs. The single-phase, single-stage, AC-DC power dual active bridge converter is one option. The phase-shift modulation is used to regulate energy flow in both directions. The topology of one stage AC-DC dual active bridge converter based in bidirectional switching modules has been introduced. This paper next introduces the analysis of the AC side current considering basic modulation functions and suggests an optimum phase-shifted modulation strategy. The proposed modulation function provides minimum harmonics distortion. A simulation study is presented to compare the proposed strategy to the basic sinusoidal and triangular modulation techniques. The results show that the modified modulation reduces the average THD by about 55% and 39% compared to the standard sinusoidal and triangular modulation strategies respectively and ensures linear relationship between the transferred power and magnitude control coefficient. [ABSTRACT FROM AUTHOR]

The Dual Active Bridge (DAB) converter is known for its advantageous characteristics, including bidirectionality, galvanic isolation, and soft-switching operation. However, achieving Zero Voltage Switching (ZVS) across the complete operation range is not guaranteed, particularly through a wide input–output voltage ratio. This paper explores the integration of the switching frequency as a control variable in the DAB converter to ensure ZVS operation across a wide voltage range, employing Single Phase Shift (SPS) modulation. The study evaluated the RMS and reactive currents under variable switching frequency, presenting the advantages of this approach. Moreover, it includes a design-oriented analysis of the ZVS limits and their relationship with the switching frequency, aiming to ensure ZVS at any operating point. Experimental results validated the theoretical analysis, while presenting the main advantages of variable switching frequency implementation. [ABSTRACT FROM AUTHOR]

Summary: In the context of the dual active bridge (DAB) bidirectional DC‐DC converter using the traditional dual‐phase‐shift (DPS) control method, a transient DC bias occurs during power co‐direction and commutation conversion. This bias negatively impacts the converter's transient performance and can lead to harsh effects, such as hard switching problems, resulting in power loss and excessive current stress. In a closed‐loop control system, poor transient response may destroy the stability of the converter. In this paper, the transient‐optimized‐dual‐phase‐shift (TODPS) control strategy is proposed to eliminate the transient DC bias and to maintain soft switching during transient states. It reduces power loss, eliminates excessive current stress, and allows for smooth transitions between single‐phase‐shift (SPS) and DPS control strategies without introducing DC bias. A closed‐loop control system based on TODPS control is established with feed‐forward compensation to adjust the primary‐side current and modify transmission power. This adjustment enhances the transient performance of the DAB converter. The proposed strategy is versatile and applicable to various power conversion scenarios involving DAB converters. It enables quick switching of the magnitude and direction of the primary‐side current during transient states, resulting in a smooth transient effect without noticeable overshoot or oscillation. The experiment results verify the effectiveness of the proposed transient optimization strategy. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper proposes a current-fed dual active bridge (DAB) converter, connected in parallel on the secondary-side AC-link, as a DC–DC converter with a high boost ratio and high input current capacity. Compared to conventional converters, the proposed converter can reduce the number of components without complicating power control and increase input current capacity. However, the parallel connection on the secondary-side AC-link could cause a circulating current. Therefore, this paper develops an equivalent circuit model of the proposed converter and theoretically analyzes the characteristics of the circulating current. The analysis reveals the influences caused by the circulating current on the proposed converter and shows a guideline for reducing the circulating current. Furthermore, using a prototype rated at 2 kW, the validity of the theoretical analysis is demonstrated through experiments. In the experiments, the validity of the theoretical analysis was confirmed, and it was verified that the proportion of the circulating current relative to the secondary-side converter’s current was less than 8% at maximum. In addition, introducing a phase-shift control on the primary-side converters reduced the input current ripple by 38.6%. Furthermore, even under conditions where the circulating current is relatively large, the efficiency drop of the proposed converter was minimal. This indicates that the influence of the circulating current on the proposed converter is sufficiently small.

This article presents a detailed procedure for deriving the generalized average model (GAM) of a dual active bridge converter. The proposed model incorporates higher orders of harmonic components to increase accuracy. Moreover, the turn ratio of the high-frequency transformer ($N_{\mathrm{t}}$) is considered for realistic modeling, which removes the conventional assumption of unity turn ratio. A detailed model of the DAB will ensure an accurate control design. Required mathematical expressions are derived and explained thoroughly, with an example showcasing a GAM model of the DAB converter up to the ninth harmonics. Several GAM models using different harmonic orders (first, third, fifth, seventh, and ninth harmonics) are derived and compared to the PLECS simulation model and a real-time simulation of the DAB converter on the PLECS RT-Box-2. Results show that including up to the ninth harmonics in the proposed model of the DAB converter leads to achieving accurate voltage and current amplitudes that are almost identical to the simulation outputs and even better than the experimental results.

ABSTRAK Indonesia bertujuan untuk beralih dari bahan bakar fosil ke sumber energi terbarukan, dengan target integrasi sebesar 23% pada tahun 2025 dan 31% pada tahun 2050. Transisi ini menghadapi tantangan akibat sifat terputus-putus dari sumber energi terbarukan yang memengaruhi kualitas listrik. Solid State Transformer (SST) muncul sebagai solusi. Dalam penelitian ini, sebuah trafo frekuensi tinggi dirancang untuk konverter Dual Active Bridge (DAB), dengan leakage inductance menjadi parameter penting. Berdasarkan perhitungan yang dilakukan, menunjukkan kebutuhan leakage inductance adalah sebesar 277 uH untuk DAB. Untuk memenuhi kebutuhan daya dan nilai leakage inductance tersebut, trafo dengan inti EE48020, 87 lilitan non-seksional, dan ketebalan isolasi 8,4 mm dapat dikembangkan. Hasil simulasi mengkonfirmasi nilai leakage inductance yang dihasilkan sebesar 268,95 uH. Kata kunci: tranformator frekuensi tinggi, dual active bridge, solid state transformer, kebocoran induktansi, geometri inti ABSTRACT Indonesia aims to shift from fossil fuels to renewable energy sources, targeting 23% integration by 2025 and 31% by 2050. This transition faces challenges due to the intermittent nature of renewable sources, impacting power quality. Solidstate transformers (SST) emerge as a solution. In this study, a high-frequency transformer (HFT) is designed for the dual active bridge (DAB), with leakage inductance being a crucial parameter. Calculations indicate a 277 uH requirement for the DAB. To meet power needs and leakage inductance values, an HFT with an EE48020 core, 87 non-sectional turns, and 8.4 mm insulation thickness is developed. Simulation results confirm a leakage inductance of 268.95 uH for the HFT. Keywords: high frequency transformer, dual active bridge, solid state transformer, leakage inductance, core geometry

Este artigo apresenta a análise e operação de um conversor CA-CC trifásico, bidirecional e isolado em alta frequência, de único estágio com correção do fator de potência, destinado para aplicação como carregador embarcado de baterias de veículos elétricos. Este conversor pode operar nos modos Grid-to-Vehicle (G2V) e Vehicle-to-Grid (V2G). No lado primário tem-se um conversor boost trifásico intercalado (interleaving) com modulação PWM senoidal para conexão com a rede elétrica, e na saída um barramento CC com ponto médio. O lado secundário é composto por uma topologia em ponte completa com modulação PWM convencional de razão cíclica de 50%. A transferência de potência do lado primário ao secundário é realizada por meio da técnica de defasamento angular (phase-shift), a mesma utilizada em conversores Dual-Active Bridge (DAB). Devido a defasagem natural do sistema trifásico, é possível obter transferência de potência constante, de reduzida ondulação, por meio do controle do defasamento angular também constante. Os princípios de operação do conversor são apresentados e demonstrados por análises qualitativas e quantitativas. Resultados experimentais de um protótipo de potência de 3 kW, tensão de entrada da rede elétrica de 127 V/60 Hz, tensão de saída de 300 V e frequência de comutação de 50 kHz são apresentados. Em conformidade com as análises, o protótipo doconversor apresentou fator de potência de 0,997, potência transferida entre primário e secundário constante e de baixa ondulação e dinâmica satisfatória e rápida durante ensaios de inversão do fluxo de potência.

Copyright of Electric Drive is the property of Electric Drive Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents a control method for an isolated bidirectional dual active bridge DC–DC converter (IBDC) where single phase shift (SPS) and variable frequency (VF) modulations are combined simultaneously with the purpose of improving the efficiency of the converter applied to the bidirectional charging of electric vehicles batteries. A complete power characterization of the dual active bridge (DAB) converter is carried out. The combined control achieves lossless turn-on and turn-off on the primary bridge for a wide range of output powers. A comparative study of power losses between the traditional SPS control and the combined method proposed here was also carried out. A prototype with an output power of 10 kW was built based on Silicon Carbide (SiC) Metal Oxide Semiconductor Field-Effect Transistors (MOSFET), with which a peak efficiency close to 99% was obtained, thus verifying the viability of the method. [ABSTRACT FROM AUTHOR]

The research work proposes a Gallium Nitride (GaN) based dual active bridge (DAB) converter for electric vehicle (EV) charging applications. The wide bandgap semiconductor device, GaN is implemented in the DAB topology of an Isolated Bidirectional DC-DC converter (IBDC). GaN-based DC-DC converters lead to higher efficiency, smaller size, faster charging, and reduced heat generation improving the overall performance of the EV charging system. The performance characteristics of GaN based DAB converter is analyzed both in simulation and hardware for EV charging application. The same analysis is extended to a Si based DAB converter and comparative results are presented. A 14.25 kW GaN based DAB and 10.5 kW Si based DAB is designed and evaluated using LTspice XVII software and a scaled-down prototype of 0.612 kW GaN based DAB and 0.25 kW Si based DAB is presented for experimental validation. Result analysis under similar operating conditions indicated an improvement of 36% more output power transfer on the GaN based DAB over the traditional Si based DAB. The developed prototype showcased improved levels of power, voltage, and current under same operating conditions. The power transmission in the developed DAB based IBDC topology is controlled using the Single-Phase-Shift (SPS) control strategy. [ABSTRACT FROM AUTHOR]

The performance and efficiency of high-frequency transformers (HFTs) are significantly influenced by leakage inductance. To improve the efficiency of HFTs, it is crucial to consider the effects of leakage inductance during the design and analysis processes. This research study aims to investigate a high-frequency toroidal transformer by examining different magnetic materials (Ferrite, Amorphas, and Iron-Powdered Alloy), winding configurations (solid, twisted, and LITZ wire), and operating frequencies (10 kHz and 50 kHz). To validate the effectiveness of parametric optimization in enhancing the system efficiency, the designed toroidal HFT was constructed and tested in a 600/300 V 3 kW dual active bridge (DAB) converter. The leakage inductances were measured using a frequency sweeping LCR meter. [ABSTRACT FROM AUTHOR]

Environmental issues and the depletion of fossil fuel resources cause increased demand for electric vehicles. An electric vehicle consists of two main components: a propulsion system and a battery charger. The design of an efficient, fast and economical charger is key to its success. Therefore, this paper presents a novel design of a dual active bridge‐based bidirectional converter with logical control for an electric vehicle application. The logical control of the converter enables the power flow between the grid and the electric vehicle and vice versa. The power flow is based on the single‐phase shift method. The converter selects the mode of operation based on the battery's state of charge and the user command using a binary switch. The power requirement influences the design of the circuit's parameters of the electric vehicle battery. A 50 V, 100 Ah, and 5 kW Li‐ion battery and AC power source of 230 V, 50 Hz are used in the simulation work. The circuit performance is verified in the SIMULINK/MATLAB environment. The analysis of the converter gives better control for various state‐of‐charge levels of electric vehicle batteries. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of electric vehicle charging station operation based on a dual active bridge topology. Two cases are considered: one with the use of a medium frequency planar transformer, the other with a conventional Litz winding transformer. An analysiswas performed using both solutions in order to compare the performance characteristics of the system for both cases and to present the differences between each transformer solution. The analysis was based on tests carried out on the full-scale model of an electric vehicle charging station, which is the result of the project "Electric vehicle charging system integrated with lighting infrastructure" realized by the Department of Drives and Electrical Machines, Lublin University of Technology. The results presented in the paper show that the conventional transformer used in the research achieved better results than the planar transformer. Based on the results obtained, the validity of using both solutions in electric vehicle charging stations was considered.

This paper introduces a design of a modular multiport converter, employing active bridges. The design incorporates a modular structure, and the paper begins by conducting steady state analyses to evaluate the converter’s characteristics. Subsequently, a RMS current equation, average current equation and power distribution equation are derived. From these equations is derived equation for delay of specific port. Lastly, a multi active bridge described in this way is verified by simulation.

Electric vehicles (EVs) are an emerging technology that contribute to reducing air pollution. This paper presents the development of a 200 kW DC charger for the vehicle-to-grid (V2G) application. The bidirectional dual active bridge (DAB) converter was the preferred fit for a high-power DC-DC conversion due its attractive features such as high power density and bidirectional power flow. A particle swarm optimization (PSO) algorithm was used to online auto-tune the optimal proportional gain (KP) and integral gain (KI) value with minimized error voltage. Then, knowing that the controller with fixed gains have limitation in its response during dynamic change, the PSO was improved to allow re-tuning and update the new KP and KI upon step changes or disturbances through a time-variant approach. The proposed controller, online auto-tuned PI using PSO with re-tuning (OPSO-PI-RT) and one-time (OPSO-PI-OT) execution were compared under desired output voltage step changes and load step changes in terms of steady-state error and dynamic performance. The OPSO-PI-RT method was a superior controller with 98.16% accuracy and faster controller with 85.28 s-1 average speed compared to OPSO-PI-OT using controller hardware-in-the-loop (CHIL) approach.

A hybrid direct current transformer (DCT) with modular multilevel structure and series-connected switches experiences current spike in sub-module branch when using original control method. The existence of current spike causes extra current stress on components. Based on the operating principle and current waveforms, an optimization modulation method is proposed, which is based on the phase shift of medium-voltage side full-bridge. The current stress of series-connected switches branch is analyzed, combined with limitation of phase shift angle for operation safety, the algorithm for the optimum phase shift angle is determined, and the optimized control strategy is established. This strategy is independent of the original power control loop, so it does not change the power transmission status and interfere with power control, which makes it easy to be put into practical application. The effectiveness of current stress reduction is verified by simulation and prototype test, and a certain improvement of efficiency is shown by the results of prototype test. Based on the analysis of operation principle and simulation and test results, the optimal control strategy is proved to have positive significance for the safe operation of equipment and selection of components.

This paper proposes two modulation schemes for Dual Active Bridge (DAB) converters, with the aim of maximizing Zero Voltage Switching (ZVS) operation over a wide operational range. The first is a ZVS-optimized constant frequency modulation scheme, constructed based on the boundary conditions of ZVS operation. This scheme maximizes the number of ZVS events across a broad operational range and is easy to implement. Additionally, a variable frequency modulation scheme is proposed, enabling continuous full ZVS operation for the DAB converter at full power and eliminating the loss of ZVS due to transitioning between modulation regions. This functionality extends the full ZVS range, yielding improved Electromagnetic Interference (EMI) performance and overall power efficiency. The synergy of the proposed modulation schemes is particularly well-suited for applications like off-board Electric Vehicle (EV) charging. Experimental validation, conducted on an 11-kW DAB converter prototype with an output voltage range of 250 V to 950 V, demonstrates the efficacy of the proposed schemes in achieving ZVS and boosting converter efficiency.

The dual active bridge (DAB) converter is widely used in applications such as energy storage systems (ESSs), charging stations, and solid-state transformers. However, input power fluctuations, such as those encountered in photovoltaic systems or fuel cells, may reduce the system’s damping and cause oscillations in the converter’s output voltage. To minimize ripples under various operating conditions, this paper proposes an optimal inductor-assisted disturbance observer-based disturbance rejection control (DOB-DRC) technique. The components of the high-frequency transformer are precisely modeled, including the series inductance, which is optimally placed for maximum power transfer. The DOB-DRC is designed for voltage regulation with minimum ripples and is compared with other control algorithms, such as current predictive control (CPC), output current feedforward control (OCFFC), and virtual direct power control (VDPC). Experimental results demonstrate that the proposed control strategy achieves fast dynamic performance, minimum overshoot, and steady-state error.

In the process of integrating renewable energy sources into DC microgrids, the isolated bidirectional bridge plays a crucial role. Under load disturbances, voltage fluctuations in the microgrid can affect system stability. This study focuses on using a Genetic Algorithm to optimize the parameters of three typical DAB controllers (PI controller based on pole placement, sliding mode controller, and model predictive controller) with the aim of improving voltage stability, especially during sudden load drops. The results demonstrate that controllers optimized using Genetic Algorithm outperform the methods of pole placement and traditional manual tuning significantly. For the PI controller, the maximum drop rate reduced from 8.00% to 4.00%. The phase margin increased from 123° to 126°. In the case of the sliding mode controller, the maximum drop rate decreased from 7.50% to 5.00%. The phase margin increased from 127° to 155°. As for the model predictive controller, the maximum drop rate reduced from 1.00% to 0.70%. The gain margin increased from 25.8 dB to 26.2 dB. These results highlight the potential of using the Genetic Algorithm in optimizing control parameters, offering the prospect of improving the performance and stability of DC–DC converters. [ABSTRACT FROM AUTHOR]

The single-phase dual active bridge (DAB) DC/DC converter is a vital component in modern power electronics systems, facilitating efficient bidirectional power transfer between various energy sources and loads. One of the critical aspects in the design of such converters is the selection of an appropriate leakage inductance, as it significantly affects the circulating power within the converter. This study investigates the influence of inductance on the reactive power flow and introduces an analytical formula for calculating the necessary leakage inductance based on the specified rated power of the DAB converter. By employing the inductance values determined through the proposed formula, the developed power control-based modulation method, implemented in discrete time, successfully achieves zero reactive power caused by the first harmonic components under all load conditions. This selection of leakage inductance optimizes the performance of the converter ensuring efficient power delivery across various applications. The applicability of this method extends to various DAB applications, including electric vehicles, integration with asynchronous microgrids, and aerospace systems.

Compared with the traditional power transformer, the cascaded PET has various functions, which integrates the functions of voltage conversion, high-frequency electrical isolation, flexible power flow control and AC/ DC power interface. In order to improve the transmission efficiency and power density of cascaded PET, it is necessary to reduce the voltage ripple of the DC sides in PET. The input stage and output stage of cascaded PET are modeled separately, and the ripple characteristics of DC side are analyzed. Compared with PI controller, PIR controller has higher gain at 100Hz is investigated. A coordinated control strategy of cascaded PET based on capacitance minimization is proposed. The input stage of PET is controlled by the traditional decoupling control method, and the output stage is controlled by phase-shift control method with PIR controller. The effectiveness and feasibility of the proposed strategy are verified by experiments. The results demonstrate that the voltage ripple can be reduced to 1/4 of the original. Within the boundary of the specified ripple, DC side capacitance can be reduced to 1/4 of the original.