Triple Active Bridge Research Articles

An Inherent Decoupled Triple-Active Bridge Converter for All-Electric Aircraft DC Power Systems

This paper focuses on a power conditioning system for an all-electric aircraft (AEA) powered by a single battery pack. The research project aims to identify a multi-port DC/DC converter topology that adequately supplies the two DC buses connected to the propulsion system and auxiliary equipment, respectively. To achieve this, a triple-active bridge (TAB) in its inherently decoupled configuration has been investigated, prototyped, and experimentally verified. The TAB voltage control system was designed, simulated, and experimentally validated. Specifically, start-up, steady-state and step-load performances were evaluated by the simulation study and then experimentally validated on a scaled prototype. The results assess the feasibility of using an inherently decoupled TAB as a power conditioning system for interconnecting the AEA battery pack with the electric propulsion and auxiliary systems. In particular, the developed TAB configuration secures the decoupled power transfer between the two output ports providing at the same time good dynamic performance in terms of voltage control during step-load variation.

Model predictive control based on single-phase shift modulation for triple active bridge DC-DC converter

The triple-active bridge (TAB) converter is widely used in various applications due to its high efficiency and power density. However, the high-frequency (HF) transformer coupling between the ports presents challenges for controller design. This article presents a model predictive control (MPC) approach based on single-phase shift modulation for the TAB converter. The developed MPC offers improved transient performance, control flexibility, and precision, ensuring compliance with DC voltage regulations and achieving optimal solutions for port decoupling. The MPC utilizes a cost function to provide robust voltage regulation, and an algorithm based on Karush-Kuhn-Tucker (KKT) conditions is developed to derive closed-form solutions for optimal control parameters. To validate the performance of the TAB converter with the proposed MPC control, Typhoon 602 hardware-in-loop (HIL) experimental case study is conducted. Additionally, a comparison with previous works is carried out to confirm the effectiveness of the proposed method. The results of the HIL experimental setup and the comparative analysis demonstrate that the developed method is effective, providing faster dynamic characteristics and port power decoupling operation capability.

A New Proposed Triple Active Bridge Converter for Fuel Cell Applications

This paper deals with a new proposed three port converter structure dedicated for two-input source hybrid systems especially for fuel cell applications. This converter is made up of three-phase triple active bridges which are galvanically isolated by means of three single phase high frequency transformers. The present converter integrates a fuel cell as the primary power source with a battery that stores energy, harnessing the unique benefits of both sources to deliver reliable power to a DC load through a single power conversion stage. In order to control the power flow between the ports, a phase shift control technique has been carried out to generate the control signals of the load and battery side bridges in reference with those of the fuel cell bridge. A detailed analysis of the proposed converter has been presented in this paper. A novel proposed energy management algorithm has been developed. This algorithm provides a robust solution for managing and distributing power flow between the converter's ports, ensuring an optimal balance of power delivery. The algorithm has been rigorously validated through simulations and experimental test, using Dspace 1104 board.

Decoupling control strategy of three-port DC–DC converter based on model prediction

Due to the use of multi winding high-frequency isolation transformers in the three port isolated bidirectional DC–DC converter to achieve port isolation and power transmission, there is a power coupling problem between each port. This article proposes a Model Prediction Control (MPC) strategy to address this issue. Considering the control objectives for each port of the Triple Active Bridge (TAB) DC–DC converter, a discrete predictive model of the TAB converter is established based on phase-shifting modulation and average model. The MPC problem is solved optimally and a predictive controller is designed with control accuracy to achieve decoupling control effect between each port. And the traditional single voltage closed-loop control, diagonal matrix decoupling control, and model predictive control proposed in this paper are compared through simulation. Finally, a TAB converter experimental platform is built based on the DSP control chip TMS320F28335. The experimental results are verified the effectiveness and superiority of the proposed method, as well as its faster dynamic characteristics and power decoupling ability between each port.

A Unified Modeling Approach for Steady State and ZVS Analysis of a Triple Active Bridge Converter

A Unified Modeling Approach for Steady State and ZVS Analysis of a Triple Active Bridge Converter

Fast Charging System of Electric Vehicle Using Optimized Isolated Multi-Port DC-DC Converter based on Modified Coati Optimization Algorithm

Once clean, renewable energy sources are used to charge the batteries in electric vehicles (EVs), the vehicles can produce zero gas emissions, greatly improving the environment. EVs and other distributed energy storage devices can be used in a smart microgrid to deliver energy to the loads throughout highest times, reducing the impact of load shading and improving the quality of the electricity. To achieve these goals of energy balance between EVs, the grid, and renewable energy sources, an isolated hybrid multiport converter is required. This paper develops an optimized isolated multi-port DC-DC converter for controlling power flow in multiple directions in an EV. This converter contains a dc-dc unidirectional converter, a bidirectional dc-dc converter, a triple active bridge (TAB), and a multi-port dual active bridge converter. Additionally, the Optimal Controller (OC) is developed to manage the power between the EV and the battery. The power flow is achieved by using the Modified Coati Optimization Algorithm (MCOA). In the MCOA, the optimal gain parameter of the converter is selected. In the planned technique, a bidirectional DC-DC converter can be considered to interconnect the EV battery towards deliver bidirectional power flow ability with the battery. The proposed approach is executed in MATLAB, and presentations are assessed by considering performance measures. Moreover, it is contrasted with the traditional approaches of particle swarm optimization (PSO) and grey wolf optimization (GWO).

Streamlined QPS Control With Magnetizing Current Injection for All-ZVS Operation in Decoupled-Type Triple Active Bridge Converters

Streamlined QPS Control With Magnetizing Current Injection for All-ZVS Operation in Decoupled-Type Triple Active Bridge Converters

Improved dynamic performance of triple active bridge DC-DC converter using differential flatness control for more electric aircraft applications

The triple active bridge (TAB) converter has been proposed to improve power density and availability in more electric aircraft applications. However, the conventional proportional-integral (PI) controller used for TAB voltage control often exhibits slow response and significant overshoot, which can impact dynamic performance. Moreover, achieving decoupling control among ports introduces computational complexity in controller design. To address these issues, this paper introduces an effective diagonal matrix decoupling strategy based on differential flatness control with single-phase shift modulation applied to a TAB converter. The proposed differential flatness control offers superior transient performance, control flexibility, and precision, ensuring compliance with DC voltage regulations while achieving optimal decoupling among ports. The comparative analysis assesses various criteria, including steady-state and dynamic performance, control complexity, and regulation and tracking properties, against PI control, unit matrix decoupling control, and the proposed differential flatness control. Hardware-in-loop (HIL) experimentation verifies the performance, confirming faster dynamic characteristics and robust port power decoupling. The results show a significant improvement in efficiency, reaching a maximum of 95.5 %, indicating reduced switching losses and enhanced overall system performance. The study concludes with a discussion on the implications of these findings and potential future research directions, such as integrating advanced optimization algorithms further to enhance the control strategy's robustness and adaptability.

GaN based isolated bidirectional multiport DC-DC converter for electric vehicle charging

The research work proposes an efficient Gallium Nitride (GaN) based isolated bidirectional DC-DC (IBDC)-Triple Active Bridge (TAB) based multi-port converter (MPC) for electric vehicle (EV) charging. The developed GaN IBDC-TAB based MPC utilizes fewer components compared to conventional IBDC charging system if designed for two output ports. The proposed GaN IBDC-TAB based MPC incorporates one input port, Port 1, and two output ports, Port 2 and Port 3 for Level-1 and Level-2 EV charging systems respectively. In addition, the developed GaN IBDC-TAB can be operated in Single Active Bridge (SAB), and Dual Active Bridge (DAB) modes as per operational requirements. A 12 kW GaN IBDC-TAB based MPC is designed and evaluated using LTspice XVII software. In TAB mode of operation, Port 2 delivers 1.5 kW, and Port 3 delivers 10.6 kW. The maximum efficiency of 98.87 % is obtained in simulation for the MPC converter in TAB mode. For experimental validation, an approximately 1 kW prototype is presented with Port 1, Port 2, and Port 3 voltages as 230 V, 120 V, and 200 V respectively with an operating frequency of 100 kHz. The single-phase-shift control strategy is implemented for controlling the transmitted power in the developed GaN IBDC-TAB based MPC.

Triple active bridge converter in nanogrid applications: A direct interface for photovoltaic modules and storage

AbstractEnvironmental issues and the global need to increase economically sustainable access to electricity addressed and boosted scientific research and use of Distributed Energy Resources, such as solar Photovoltaic (PV). Multi‐port power converters can be of great interest for a compact and efficient interface between PV, storage units, and DC loads. The Triple Active Bridge (TAB) shows interesting advantages in terms of isolation and Zero Voltage Switching capabilities over wide load and input voltage ranges. This work aims to develop a TAB prototype for a NanoGrid (NG) application, analyzing the possibility of a direct interface of PV modules, storage units, and DC loads, without the use of intermediate conversion stages. The TAB prototype uses Gallium Nitride devices, and an evaluation of the overall efficiency is provided, useful to compare with other isolated three‐port converters. Through an analytical approach, a TAB has been sized and optimized to meet specific application requirements. MATLAB/Simulink simulations have been done for the sizing validation and the control strategy design. A prototype has been developed and experimental measurements have been compared with simulation results. The TAB is proposed as a key element of DC NGs, but applications of interest are also automotive, More Electric Aircraft, and naval applications.

A decentralized coordinated control scheme for the DC network with a multiport converter

For complex networks with multiple subgrids formed by solid-state transformers, existing studies primarily focus on coordination within the networks in islanded mode, overlooking cooperation in grid-connected mode. To address this gap, this paper proposes a coordinated control scheme for the triple active bridge (TAB) converter in the grid-connected DC network. By establishing a droop relationship between the input power and the voltage difference, the TAB converter facilitates coordination between the utility grid and the DC network. The energy exchange with the utility grid is not only regulated by the TAB converter but also adjusted according to the utility grid state. So, the proposed scheme effectively facilitates coordination between the higher- and lower-level networks, strengthening system stability. Besides, the proposed scheme employs a unified control structure, which has power sharing and voltage regulation capabilities in grid-connected mode, as well as operating in islanded mode. This control structure enables the TAB converter to seamlessly transition across different operation modes, avoiding mode switching process and reducing the control complexity. Moreover, the proposed scheme is decentralized which negates the necessity for communication links, bolstering the system reliability. Lastly, the feasibility of the proposed scheme is analyzed in theory and validated by the hardware-in-loop tests.

Optimization of Reflux Power in Triple Active Bridge With Online Particle Swarm Optimization and Exponential Weighted Moving Average Algorithm

Optimization of Reflux Power in Triple Active Bridge With Online Particle Swarm Optimization and Exponential Weighted Moving Average Algorithm

An Efficiency Improvement Strategy for Triple-Active-Bridge-Based DC Energy Routers in DC Microgrids

A triple-active bridge (TAB) can be used as a power conversion unit in a three-port DC energy router (DCER) such as a triple-active bridge-based DC energy router (TAB-DCER). The operational loss of a TAB can be seen as a key factor affecting the efficiency of a TAB-DCER. However, the RMS value of the inductor current of the TAB-DCER increases under single-phase shift (SPS) control, and this greatly increases the system operating losses. The use of phase-shifted plus PWM (PS-PWM) control can reduce the RMS value of the inductor current, but its mathematical model is complex, and involves difficult calculations. To address this problem, in the study reported here, we developed an optimal control strategy for the RMS value of the inductor current based on TAB-DCER. First, the working principle of a TAB-DCER under PS-PWM control was analyzed, and a circuit decomposition model was established. Second, the operating modes under PS-PWM control were analyzed, and corresponding expressions of port power and the RMS value of the inductor current were obtained. Third, an optimized mathematical model of the sum of squares of the RMS value of the inductor current of the TAB-DCER was constructed. Finally, a genetic algorithm was used to solve the mathematical model and derive the optimal phase shift angle; this resulted in a lower RMS value of the inductor current in the TAB-DCER and reduced the system operating losses. The simulation and experimental results show that the TAB-DCER used in the present study can reduce operating losses, improve system efficiency, and deliver coordinated power control.

Simplified control of TAB converter for scalable multibattery charging system

SummaryThe integration of distributed energy resources (DERs) into DC microgrids has become commonplace in many applications, including electric vehicle (EV) systems that use batteries, fuel cells, and supercapacitors as energy storage systems. To make a sustainable charging system for electric vehicles, DERs can be used in conjunction with the grid. In many cases, charging systems based on isolated DC‐DC converters, such as the dual active bridge (DAB) converter, with various controls, are typically used. However, integrating multiple DERs at the common input DC link can result in a loss of isolation in the DAB converter and also leads to problems with circulating current. To maintain isolation, multiple DAB converters can be used, but this increases the system's size. Alternatively, the multiport isolated DC‐DC converter can address such issues but introduces complexities such as cross‐coupling between power flow. This paper proposes a hardware decoupling control methodology for a triple active bridge (TAB) based isolated DC‐DC converter, with power routing features for simultaneously charging two EV's battery stack. Through hardware decoupling control, appropriate passive components are designed and selected to connect with the individual H‐bridges of the TAB for power decoupling. The paper discusses the cross‐coupling issue in the TAB and describes a methodology derived from mathematical expressions for achieving power decoupling. For validation of the control, a 5 kW system is modeled in MATLAB Simulink, and the results demonstrate how the proposed approach overcomes cross‐coupling issues. Further, a 500 W hardware prototype has been developed to validate the proposed approach.

Simplified Power Decoupling Control of Triple Active Bridge Converter in Polar Coordinate System for EV Application

Simplified Power Decoupling Control of Triple Active Bridge Converter in Polar Coordinate System for EV Application

Power Decoupling Enhancement of a Triple Active Bridge Converter With Feedforward Compensation Based on Model Predictive Control and Fuzzy Logic Controller in DC Microgrid Systems

Power Decoupling Enhancement of a Triple Active Bridge Converter With Feedforward Compensation Based on Model Predictive Control and Fuzzy Logic Controller in DC Microgrid Systems

Impedance Modeling and Stability Analysis of Triple-Active-Bridge-Converter-Based Renewable-Electricity-Hydrogen-Integrated Metro DC Traction Power System

DC power supply system has been widely applied in metro traction power system. This article presents a novel framework for future metro traction power system (MTPS) with renewable energy, named renewable electricity-hydrogen-integrated metro traction power system (RMTPS), to reduce overall energy consumption and carbon emission of the MTPS. The framework and operation modes of RMTPS are first developed, where triple active bridge (TAB) converter-based multi-port metro energy router (MMER) is innovatively presented to integrate electricity subsystem, hydrogen subsystem and MTPS. Then, an impedance modelling method of MMER is developed based on the extra element theorem (EET). It can adaptively obtain terminal impedance characteristics of MMER considering the effect of multi-directional power flow and source/load characteristic variation on other terminals. Further, the stability of RMTPS under different operation modes is investigated based on the developed impedance modelling method. Simulation and experimental results are given to validate the effectiveness of the proposed impedance model and stability analysis for RMTPS. The proposed method can further benefit stability design of multi-port metro energy router in practical application.

A Simplified All-ZVS Strategy for High-Frequency Triple Active Bridge Converters With Designed Magnetizing Inductance

A Simplified All-ZVS Strategy for High-Frequency Triple Active Bridge Converters With Designed Magnetizing Inductance

Enhanced Excitation Converter With Parallel/Series DC-Link Based on TAB for DFIG to Improve the LVRT Capability Under Severe Grid Faults

The low-voltage ride-through (LVRT) capability of the doubly-fed induction generator (DFIG) based on the conventional excitation converter is insufficient under severe grid faults. The reason is that the dynamic rotor electromotive forces (EMF) will far exceed the dc-link voltage. To solve this issue, this letter proposes an enhanced excitation converter with parallel/series dc-link based on the triple active bridge (TAB) for DFIG. The dc-link of the enhanced excitation converter consists of the TAB and switching circuit, replacing the capacitive-type dc-link. Based on this topology, the dc-link voltage can increase instantaneously during severe grid faults to resist rotor EMF and improve the LVRT capability of DFIG. Compared with existing LVRT schemes, the enhanced excitation converter enables DFIG to achieve LVRT and inject the reactive current requirements of the grid code into the grid under severe grid faults. Finally, experiments verified the effectiveness of the proposed enhanced excitation converter and its control strategy.

Comparative Analysis and Optimization of Triple Active Bridge Transformer Configuration With Integrable Leakage Inductance

Comparative Analysis and Optimization of Triple Active Bridge Transformer Configuration With Integrable Leakage Inductance