{"title":"An LLC resonant converter with wide output range fixed frequency PWM control for PEV charging applications","authors":"Dangshu Wang, Menghu Chang, Licong Zhao, Yuxuan Yang, Zhimin Guan","doi":"10.1108/cw-06-2023-0137","DOIUrl":null,"url":null,"abstract":"<h3>Purpose</h3>\n<p>This study aims to regarding the application of traditional pulse frequency modulation control full-bridge LLC resonant converters in wide output voltage fields such as on-board chargers, there are issues with wide frequency adjustment ranges and low conversion efficiency.</p><!--/ Abstract__block -->\n<h3>Design/methodology/approach</h3>\n<p>To address these issues, this paper proposes a fixed-frequency pulse width modulation (PWM) control strategy for a full-bridge LLC resonant converter, which adjusts the gain by adjusting the duty cycle of the switches. In the full-bridge LLC converter, the two switches of the lower bridge arm are controlled by a fixed-frequency and fixed duty cycle, with their switching frequency equal to the resonant frequency, whereas the two switches of the upper bridge arm are controlled by a fixed-frequency PWM to adjust the output voltage. The operation modes of the converter are analyzed in detail, and a mathematical model of the converter is established. The gain characteristics of the converter under the fixed-frequency PWM control strategy are deeply analyzed, and the conditions for implementing zero-voltage switching (ZVS) soft switching in the converter are also analyzed in detail. The use of fixed-frequency PWM control simplifies the design of resonant parameters, and the fixed-frequency control is conducive to the design of magnetic components.</p><!--/ Abstract__block -->\n<h3>Findings</h3>\n<p>According to the fixed-frequency PWM control strategy proposed in this paper, the correctness of the control strategy is verified through simulation and the development and testing of a 500-W experimental prototype. Test results show that the primary side switches of the converter achieve ZVS and the secondary side rectifier diodes achieve zero-current switching, effectively reducing the switching losses of the converter. In addition, the control strategy reduces the reactive circulating current of the converter, and the peak efficiency of the experimental prototype can reach 95.2%.</p><!--/ Abstract__block -->\n<h3>Originality/value</h3>\n<p>The feasibility of the fixed-frequency PWM control strategy was verified through experiments, which has significant implications for improving the efficiency of the converter and simplifying the design of resonant parameters and magnetic components in wide output voltage fields such as on-board chargers.</p><!--/ Abstract__block -->","PeriodicalId":50693,"journal":{"name":"Circuit World","volume":"135 1","pages":""},"PeriodicalIF":0.8000,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Circuit World","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1108/cw-06-2023-0137","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose
This study aims to regarding the application of traditional pulse frequency modulation control full-bridge LLC resonant converters in wide output voltage fields such as on-board chargers, there are issues with wide frequency adjustment ranges and low conversion efficiency.
Design/methodology/approach
To address these issues, this paper proposes a fixed-frequency pulse width modulation (PWM) control strategy for a full-bridge LLC resonant converter, which adjusts the gain by adjusting the duty cycle of the switches. In the full-bridge LLC converter, the two switches of the lower bridge arm are controlled by a fixed-frequency and fixed duty cycle, with their switching frequency equal to the resonant frequency, whereas the two switches of the upper bridge arm are controlled by a fixed-frequency PWM to adjust the output voltage. The operation modes of the converter are analyzed in detail, and a mathematical model of the converter is established. The gain characteristics of the converter under the fixed-frequency PWM control strategy are deeply analyzed, and the conditions for implementing zero-voltage switching (ZVS) soft switching in the converter are also analyzed in detail. The use of fixed-frequency PWM control simplifies the design of resonant parameters, and the fixed-frequency control is conducive to the design of magnetic components.
Findings
According to the fixed-frequency PWM control strategy proposed in this paper, the correctness of the control strategy is verified through simulation and the development and testing of a 500-W experimental prototype. Test results show that the primary side switches of the converter achieve ZVS and the secondary side rectifier diodes achieve zero-current switching, effectively reducing the switching losses of the converter. In addition, the control strategy reduces the reactive circulating current of the converter, and the peak efficiency of the experimental prototype can reach 95.2%.
Originality/value
The feasibility of the fixed-frequency PWM control strategy was verified through experiments, which has significant implications for improving the efficiency of the converter and simplifying the design of resonant parameters and magnetic components in wide output voltage fields such as on-board chargers.
期刊介绍：
Circuit World is a platform for state of the art, technical papers and editorials in the areas of electronics circuit, component, assembly, and product design, manufacture, test, and use, including quality, reliability and safety. The journal comprises the multidisciplinary study of the various theories, methodologies, technologies, processes and applications relating to todays and future electronics. Circuit World provides a comprehensive and authoritative information source for research, application and current awareness purposes.
Circuit World covers a broad range of topics, including:
• Circuit theory, design methodology, analysis and simulation
• Digital, analog, microwave and optoelectronic integrated circuits
• Semiconductors, passives, connectors and sensors
• Electronic packaging of components, assemblies and products
• PCB design technologies and processes (controlled impedance, high-speed PCBs, laminates and lamination, laser processes and drilling, moulded interconnect devices, multilayer boards, optical PCBs, single- and double-sided boards, soldering and solderable finishes)
• Design for X (including manufacturability, quality, reliability, maintainability, sustainment, safety, reuse, disposal)
• Internet of Things (IoT).
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
