A Control Design Technology of Isolated Bidirectional LLC Resonant Converter for Energy Storage System in DC Microgrid Applications

This paper presents a new control method for a bidirectional DC–DC LLC resonant topology converter. The proposed converter can be applied to power the conversion between an energy storage system and a DC bus in a DC microgrid or bidirectional power flow conversion between vehicle-to-grid (V2G) behav...

Full description

Bibliographic Details
Main Authors: You-Kun Tai, Kuo-Ing Hwu
Format: Article
Language:English
Published: MDPI AG 2023-09-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/16/19/6877
_version_ 1797575955804323840
author You-Kun Tai
Kuo-Ing Hwu
author_facet You-Kun Tai
Kuo-Ing Hwu
author_sort You-Kun Tai
collection DOAJ
description This paper presents a new control method for a bidirectional DC–DC LLC resonant topology converter. The proposed converter can be applied to power the conversion between an energy storage system and a DC bus in a DC microgrid or bidirectional power flow conversion between vehicle-to-grid (V2G) behavior and grid-to-vehicle (G2V) behavior. Furthermore, such a converter can be applied to energy storage systems for decentralized renewable energy generation systems, such as solar and wind power. In addition, this converter can be combined with a bidirectional inverter to allow energy storage in the system to improve the safety, stability, and power quality of the microgrid. In the proposed circuit structure, we use a bidirectional DC–DC LLC, which has the advantages of a higher voltage conversion ratio, lower part count, simpler control than similar converters such as DAB, CLLC, and L–LLC converters, and bidirectional power flow and electrical isolation. Specifically, to extend the battery life, it can be employed as a control strategy for discharging the energy stored in the battery (SOC) and reducing the temperature rise generated by the internal solid electrolyte interphase (SEI) when discharging the battery under the variation in distributed energy resource (DER) generation and load demand. To realize the bidirectional power conversion without using any auxiliary inductor and only changing the control strategy, the forward step-down power conversion was based on pulse frequency modulation (PFM) control, and the reverse step-up power conversion was based on pulse width modulation (PWM) control. In this paper, we introduce the bidirectional converter topology and its control strategy for the DC microgrid battery energy storage system. Finally, a 500 W prototype is built to verify the effectiveness of the proposed converter.
first_indexed 2024-03-10T21:45:41Z
format Article
id doaj.art-6285445d0db04fa799971e2093f73d7b
institution Directory Open Access Journal
issn 1996-1073
language English
last_indexed 2024-03-10T21:45:41Z
publishDate 2023-09-01
publisher MDPI AG
record_format Article
series Energies
spelling doaj.art-6285445d0db04fa799971e2093f73d7b2023-11-19T14:20:07ZengMDPI AGEnergies1996-10732023-09-011619687710.3390/en16196877A Control Design Technology of Isolated Bidirectional LLC Resonant Converter for Energy Storage System in DC Microgrid ApplicationsYou-Kun Tai0Kuo-Ing Hwu1Department of Electrical Engineering, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd, Taipei 10608, TaiwanDepartment of Electrical Engineering, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd, Taipei 10608, TaiwanThis paper presents a new control method for a bidirectional DC–DC LLC resonant topology converter. The proposed converter can be applied to power the conversion between an energy storage system and a DC bus in a DC microgrid or bidirectional power flow conversion between vehicle-to-grid (V2G) behavior and grid-to-vehicle (G2V) behavior. Furthermore, such a converter can be applied to energy storage systems for decentralized renewable energy generation systems, such as solar and wind power. In addition, this converter can be combined with a bidirectional inverter to allow energy storage in the system to improve the safety, stability, and power quality of the microgrid. In the proposed circuit structure, we use a bidirectional DC–DC LLC, which has the advantages of a higher voltage conversion ratio, lower part count, simpler control than similar converters such as DAB, CLLC, and L–LLC converters, and bidirectional power flow and electrical isolation. Specifically, to extend the battery life, it can be employed as a control strategy for discharging the energy stored in the battery (SOC) and reducing the temperature rise generated by the internal solid electrolyte interphase (SEI) when discharging the battery under the variation in distributed energy resource (DER) generation and load demand. To realize the bidirectional power conversion without using any auxiliary inductor and only changing the control strategy, the forward step-down power conversion was based on pulse frequency modulation (PFM) control, and the reverse step-up power conversion was based on pulse width modulation (PWM) control. In this paper, we introduce the bidirectional converter topology and its control strategy for the DC microgrid battery energy storage system. Finally, a 500 W prototype is built to verify the effectiveness of the proposed converter.https://www.mdpi.com/1996-1073/16/19/6877bidirectional DC–DC converterLLC topologypush–pull topologyresonant converterzero voltage switching
spellingShingle You-Kun Tai
Kuo-Ing Hwu
A Control Design Technology of Isolated Bidirectional LLC Resonant Converter for Energy Storage System in DC Microgrid Applications
Energies
bidirectional DC–DC converter
LLC topology
push–pull topology
resonant converter
zero voltage switching
title A Control Design Technology of Isolated Bidirectional LLC Resonant Converter for Energy Storage System in DC Microgrid Applications
title_full A Control Design Technology of Isolated Bidirectional LLC Resonant Converter for Energy Storage System in DC Microgrid Applications
title_fullStr A Control Design Technology of Isolated Bidirectional LLC Resonant Converter for Energy Storage System in DC Microgrid Applications
title_full_unstemmed A Control Design Technology of Isolated Bidirectional LLC Resonant Converter for Energy Storage System in DC Microgrid Applications
title_short A Control Design Technology of Isolated Bidirectional LLC Resonant Converter for Energy Storage System in DC Microgrid Applications
title_sort control design technology of isolated bidirectional llc resonant converter for energy storage system in dc microgrid applications
topic bidirectional DC–DC converter
LLC topology
push–pull topology
resonant converter
zero voltage switching
url https://www.mdpi.com/1996-1073/16/19/6877
work_keys_str_mv AT youkuntai acontroldesigntechnologyofisolatedbidirectionalllcresonantconverterforenergystoragesystemindcmicrogridapplications
AT kuoinghwu acontroldesigntechnologyofisolatedbidirectionalllcresonantconverterforenergystoragesystemindcmicrogridapplications
AT youkuntai controldesigntechnologyofisolatedbidirectionalllcresonantconverterforenergystoragesystemindcmicrogridapplications
AT kuoinghwu controldesigntechnologyofisolatedbidirectionalllcresonantconverterforenergystoragesystemindcmicrogridapplications