电压隔离型混合半桥三电平LLC-DCT特性分析  

Characteristic Analysis of Voltage Isolated Hybrid Half-bridge Tri-level LLC-DCT

作　　者：柳龙 安昱[1] 陈雪 LIU Long;AN Yu;CHEN Xue(Xu Ji Group Co.Ltd,Xuchang 461000,Henan Province,China;Xi’an XJ Power Electronics Technology Co.Ltd,Xi’an 710000,Shaanxi Province,China)

机构地区：[1]许继集团有限公司,河南省许昌市461000 [2]西安许继电力电子技术有限公司,陕西省西安市710000

出　　处：《中国电机工程学报》2020年第21期7022-7035,共14页Proceedings of the CSEE

基　　金：国家电网有限公司科技项目“直流配网用关键设备拓扑研究及样机研制”(PDB17201700161)。

摘　　要：文中针对直流变压器现有体积大、成本高等问题,提出一种隔离级混合型三电平双向LLC-DCT拓扑,此拓扑具有电压等级高的特点,从而降低直流变压器系统所需模块数量,减少系统占地面积和成本。该拓扑采用等效脉冲扩展发波法,可以实现能量双向流动、全范围软开关以及串联器件的均压。对该方法进行模态分析和理论研究,并分析增益特性以及软开关和串联器件均压所需要满足的条件。最后,分别搭建仿真平台和一台3kW、1kV-280V的模块实验样机。仿真和实验结果表明,该方法的电压增益偏差小于1%,可以实现双侧双向零电压开关和准零电流开关,串联器件不均压度小于1%。Aiming at the problems of large size and high cost of DC transformers, the isolation stage hybrid three-level bidirectional LLC-DCT topology was proposed. This topology has the characteristics of high bus voltage level, which reduced the number of modules number of DC transformer system and reduced its volume and cost. This topology used the equivalent pulse-spread generation method to achieve energy bidirectional flow and full range soft-switch as well as voltage equalization of series devices. The modal analysis and theoretical study of the method were carried out, and analyzed the gain characteristics and the conditions that need to be met for soft-switch and series device voltage equalization. Finally, the simulation platform and a 3 kW 1 kV-280 V module experimental prototype were built respectively. The simulation and experimental results show that the voltage gain deviation of this method is less than 1%, the bi-directional zero voltage switching(ZVS) and quasi-zero current switching(ZCS) can be realized, and the non-uniformity of series devices is less than 1%.

关 键 词：直流变压器 三电平 LLC 双向 软开关 

分 类 号：TM464[电气工程—电器]