Modeling and Current Programmed Control of a Bidirectional Full Bridge DC-DC Converter

Modelling of bidirectional full bridge DC-DC converter as one of the most applicable converters has received significant attention. Mathematical modelling reduces the simulation time in comparison with detailed circuit response;moreover it is convenient for controller design purpose. Due to simple and effective methodology, average state space is the most common method among the modelling methods. In this paper a bidirectional full bridge converter is modelled by average state space and for each mode of operations a controller is designed. Attained mathematical model results are in a close agreement with detailed circuit simulation.

Design and Analysis of a 24 Vdc to 48 Vdc Bidirectional DC-DC Converter Specifically for a Distributed Energy Application

The design of a bidirectional dc-dc power converter specifically for a distributed energy application is presented. The existing two different DC voltage battery bank of the distributed generation needs to interlink each other using a bi-directional dc-dc converter in order to minimize the unbalance of the output load currents of the three inverters connected to electric grid system. Through this connection, a current can flow from one system to another or vice versa depending on which systems need the current most. Thus, unbalanced currents of the grid line have been minimized and the reliability and performance of the DER grid connected system has been increased. A detailed mathematical analysis of the converter under steady state and transient condition are presented. Mathematical models for boost and buck modes are being derived and the simulink model is constructed in order to simulate the system. Moreover, the model has been validated on the actual operation of the converter, showing that the simulated results in Matlab Simulink are consistent with the experimental ones.

Experimental Evaluation of Medium-Voltage Cascode Gallium Nitride(GaN)Devices for Bidirectional DC-DC Converters

Wide bandgap(WBG)semiconductors,such as silicon carbide(SiC)and gallium nitride(GaN),exhibit superior physical properties and demonstrate great potential for replacing conventional silicon(Si)semiconductors with WBG technology,pushing the boundaries of power devices to handle higher blocking voltages,switching frequencies,output power levels,and operating temperatures.However,tradeoffs in switching performance and converter efficiency when substituting GaN devices for Si and SiC counterparts are not well-defined,especially in a cascode configuration.Additional research with further detailed investigation and analysis is necessitated for medium-voltage GaN devices in power converter applications.Therefore,the aim of this research is to experimentally investigate the impact of emerging 650/900 V cascode GaN devices on bidirectional dc-dc converters that are suitable for energy storage and distributed renewable energy systems.Dynamic characteristics of Si,SiC,and cascode GaN power devices are examined through the double-pulse test(DPT)circuit at different gate resistance values,device currents,and DC bus voltages.Furthermore,the switching behavior and energy loss as well as the rate of voltage and current changes over the time are studied and analyzed at various operating conditions.A 500 W experimental converter prototype is implemented to validate the benefits of cascode GaN devices on the converter operation and performance.Comprehensive analysis of the power losses and efficiency improvements for Si-based,SiC-based,and GaN-based converters are performed and evaluated as the switching frequency,working temperature,and output power level are in-creased.The experimental results reveal significant improvements in switching performance and energy efficiency from the emerging cascode GaN devices in the bidirectional converters.

A Resonant Dual Full-Bridge Class-E Bidirectional DC-DC Converter for Fuel Cell Electric Vehicle

The interests on energy storage schemes, bidirectional dc-dc converter and uninterruptible power supplies have been increasing nowadays as there wide researches are undertaken in the area of electric vehicles. A modified bi directional class-E resonant dc-dc converter is introduced here in this proposed topology for the application in electric vehicles. The advantages of soft switching techniques have been utilized for making analysis simple. The main advantage here in this system is that it can operate in a wide range of frequencies with minimal switching loss in transistors. This paper elaborates a detailed analysis on converter design and the same has been simulated and verified in Matlab/Simulink.

A Review of Isolated Bidirectional DC-DC Converters for Data Centers

In today’s fast-paced,information-driven world,data centers can offer high-speed,intricate capabilities on a larger scale owing to the ever-growing demand for networks and information systems.Because data centers process and transmit information,stability and reliability are important.Data center power supply architectures rely heavily on isolated bidirectional DC-DC converters to ensure safety and stability.For the smooth operation of a data center,the power supply must be reliable and uninterrupted.In this study,we summarize the basic principle,topology,switch conversion strategy,and control technology of the existing isolated bidirectional DC-DC converters.Subsequently,existing research results and problems with isolated bidirectional DC-DC converters are reviewed.Finally,future trends in the development of isolated bidirectional DC-DC converters for data centers are presented,which offer valuable insights for solving engineering obstacles and future research directions in the field.

The Hybrid Bidirectional DC/DC Converter:Mutual Control and Stability Analysis

A hybrid bidirectional DC/DC converter(BDC)is proposed as the fundamental DC/DC module in solid-state transformers,which combines a bidirectional LLC converter and a dual-active-bridge(DAB)converter.Integrated with a mutual control scheme,both parts of this hybrid BDC can be unified into an interdependent community.In this hybrid BDC,the LLC converter supports the output voltage and improves stability by working at the resonant frequency mode and the DAB converter enhances the BDC power capability by controlling the LLC output current constant.The BDC can achieve the full-load-range soft switching of all active switches by designing the auxiliary inductor of LLC and the minimum output current of DAB.By comparing to the single DAB,the proposed BDC has the higher phase and gain margin which means the BDC improved the relative stability based on Nyquist criterion.To solve the bidirectional power control problem,a dead-band voltage control logic is adopted which can determine the BDC’s power direction based on the output voltage change.A 200 V experimental system has verified the aforementioned features and functions of the BDC.

Quasi-Z-Source Based Bidirectional DC-DC Converter and Its Control Strategy

This paper presents a quasi-Z-source based isolated bidirectional DC-DC converter(qZIBDC)for renewable energy applications.The converter utilizes a dual active bridge circuit with a quasi-Z-source network on both sides,so the converter works as buck/boost converter from either side.It has a wider input/output voltage operating range,soft-switching capabilities without additional devices,and higher boost capability than a traditional dual active bridge circuit.Apart from that,shoot-through states are incorporated in its operating cycle to boost the input voltage resulting in high reliability of the proposed converter.Due to the symmetrical structure of the circuit,there is no defined high voltage or low voltage side as in traditional isolated bidirectional DC-DC converter.The operating principle and control strategy of the proposed converter are presented.Simulation and experimental results are provided to verify the effectiveness of the proposed converter topology and its control strategy.

Non-isolated stacked bidirectional soft-switching DC-DC converter with PWM plus phase-shift control scheme

In this paper, a non-isolated stacked bidirectional DC-DC converter with zero-voltage-switching(ZVS) is introduced for the high step-up/step-down conversion systems. The extremely narrow turn-on and/or turn-off duty cycle existing in the conventional bidirectional buck-boost converters can be extended due to the stacked module configuration for large voltage conversion ratio applications. Furthermore, the switch voltage stress is halved because of the series connection of half bridge modules. The PWM plus phase-shift control strategy is employed, where the duty cycle is adopted to regulate the voltages between the input and output sides and the phaseshift angle is applied to achieve the power flow regulation.This decoupled control scheme can not only realize seamless bidirectional transition operation, but also achieve adaptive voltage balance for the power switches. In addition, ZVS soft-switching operation for all active switches is realized to minimize the switching losses. Finally, a prototype of 1 kW operating at 100 kHz is built and tested to demonstrate the effectiveness of the proposed converter and the control strategy.