基于双模式变频移相调制的单级式双有源桥型DC-AC变换器  

A Single-Stage Dual Active Bridge DC-AC Converter Based on Dual Mode Modulation of Variable Frequency and Phase Shift

作　　者：王要强[1,2] 李灏 李想 聂福全[3] 陈天锦 梁军[1,6] Wang Yaoqiang;Li Hao;Li Xiang;Nie Fuquan;Chen Tianjin;Liang Jun(School of Electrical and Information Engineering Zhengzhou University,Zhengzhou 450001 China;Henan Engineering Research Center of Power Electronics and Energy Systems,Zhengzhou 450001 China;School of Mechanical and Electrical Engineering Henan Institute of Science and Technology,Xinxiang 453003 China;XJ Power Co.Ltd,Xuchang 461000 China;Henan Key Laboratory of Intelligent Charging Technology,Xuchang 461000 China;School of Engineering Cardiff University,Cardiff CF243AA UK)

机构地区：[1]郑州大学电气与信息工程学院,郑州450001 [2]河南省电力电子与电力系统工程技术研究中心,郑州450001 [3]河南科技学院机电学院,新乡453003 [4]许继电源有限公司,许昌461000 [5]河南省智能充电技术重点实验室,许昌461000 [6]卡迪夫大学工程学院,英国卡迪夫CF243AA

出　　处：《电工技术学报》2024年第21期6865-6876,共12页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(51507155,52307227);中央引导地方科技发展资金(2022ZY0134);国家资助博士后研究人员计划(GZB20230667);河南省科协青年人才托举工程项目(2024HYTP020)资助。

摘　　要：针对单级式双有源桥(DAB)型DC-AC变换器关断电流较大和软开关范围有限的问题,该文提出一种双模式变频移相调制策略。首先,对DAB变换器的单移相(SPS)调制和扩展移相(EPS)调制进行时域分析,得到其功率传输特性;然后,分析变换器的关断电流与软开关条件,得到移相比和开关频率约束方程;在此基础上,分析双模式间的移相比边界条件,提出变换器运行模式的切换机制,从而在实现变换器单级功率变换的同时,保证全范围软开关并降低低压侧的关断电流;最后,通过仿真和实验验证了所提调制策略的有效性与可行性。In electric vehicle charging systems,energy storage systems,and solid-state transformers,isolated DC-AC converters serve as crucial energy conversion nodes.The single-stage dual active bridge(DAB)DC-AC converter structure achieve power transmission functions in a single stage,which effectively reducing volume and improving reliability.In reality,turn-off current is crucial for achieving zero-voltage switching(ZVS),however,high turn-off current can result in additional turn-off losses.Moreover,the low-voltage side usually bears a greater turn-off current,especially under high turns ratio conditions.This paper proposes a frequency-variable dual-mode switching modulation strategy based on single-phase-shift(SPS)and extended-phase-shift(EPS)control,which can reduce the turn-off current of the low-voltage side for the converter and achieve ZVS in the ac line voltage range.Firstly,the time-domain analysis is conducted on the SPS modulation and EPS modulation strategies for the DAB converter,and obtain their power transmission characteristics.Secondly,in order to achieve full-range ZVS,the turn-off currents of some switches are fixed at a constant value,the three phase-shift-ratios(D,D1 and D2)and switching frequency constraint equations are derived.Thirdly,the phase-shift-ratio and switching frequency trajectories of the converter under different turn-off current are analyzed in detail.When the turn-off current of DC and AC sides are set different low values,the switching frequency will increase seriously and the value of phase-shift-ratio D2 will exceed 1 near the voltage zero-crossing.This will cause a distortion of power transmission in the converter,leading to grid current distortion.Therefore,a frequency-shifted dual-mode-switching modulation strategy is proposed and the switching boundaries for the two operating modes are derived.During the time period of phase-shift-ratio D2 is lower than 1,the variable-frequency EPS modulation strategy is employed.When period of phase-shift ratio D2 is more than 1,the internal

关 键 词：DC-AC变换器 双有源桥变换器 双模式调制 关断电流 软开关 

分 类 号：TM46[电气工程—电器]