The ZVS Transition Analysis and Optimization for CLLC-Type Resonant DC Transformer
The ZVS Transition Analysis and Optimization for CLLC-Type Resonant DC Transformer
复制标题
CLLC型谐振直流变压器的ZVS过渡分析与优化
DOI：
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
R. Burgos
中科院分区：
文献类型：
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作者：
Yuliang Cao;Minh Ngo;D. Dong;R. Burgos
隔离式双向直流Transformer（DCX）在储能系统、数据中心电源和交通电气化等领域得到了广泛的应用。由于零电压开关（ZVS）和小均方根电流，CLLC谐振变换器被认为是一个很好的候选人DCX时，它工作在谐振频率与开环恒压增益。针对传统同步整流（SR）调制方式下CLLC-DCX双向功率流不平滑和电流畸变的问题，采用了双有源同步（DAS）调制方式。首先，在考虑器件输出电容较大的情况下，对DAS调制的开关过渡进行了充分的研究。通过比较七种不同的开关转换类型，由于ZVS，无死区导通损耗和负载无关的电压传输比，因此优选所谓的“Sync-ZVS”转换。为了实现“同步-零电压”过渡，提出了一种“轴中心对称”（ACS）方法。最后，一个18千瓦500 kHz的开环CLLC-DCX建立验证的“同步ZVS”的过渡和建议的“ACS”的方法。
The isolated bidirectional dc transformer (DCX) has been widely used in the energy storage systems, data center power supplies and transportation electrification. Due to zero voltage switching (ZVS) and small rms current, CLLC resonant converter is considered a good candidate for DCX when it works at resonant frequency with an open-loop constant voltage gain. To address the problem of unsmooth bidirectional power flow and current distortion in the CLLC-DCX with traditional synchronization rectification (SR) modulation, dual-active synchronization (DAS) modulation is adopted, with which the gate signals on primary and secondary side are the same. First of all, after considering the large output capacitance of the device, the switching transition of DAS modulation is fully studied. With the comparison between seven different switching transition types, a so-called “Sync-ZVS” transition is preferred due to ZVS, no deadtime conduction loss, and load-independent voltage transfer ratio. To realize “Sync-ZVS” transition, this paper proposes an “Axis and Center Symmetric” (ACS) method. Finally, an 18 kW 500kHz open-loop CLLC-DCX was built to verify both the “Sync-ZVS” transition and the proposed “ACS” method.