摘要
直流微电网内多采用具有高功率密度和高能量密度的混合储能系统维持微电网内功率平衡,并进行电压控制。针对该应用背景,文章提出了一种直流微电网混合储能用多谐振三端口变换器(采用LCLC多谐振结构)。该结构具有3个谐振频率,通过参数设计令3个谐振频率分别为:基频和三倍频的串联谐振频率以及二倍频的并联谐振频率。由于多谐振腔具有基频和三倍频2个串联谐振频率,使得谐振腔能够同时传递基频和三倍频能量,提高了功率传输能力,同时提升了轻载情况下的开关管关断电流,扩大了轻载情况下ZVS软开关范围。此外,提出了一种驱动频率最优化控制方法,根据变换器的输出功率调节驱动频率,以保证变换器的效率最优,同时通过调节移相角的大小和方向控制三端口间的能量传输。最后,设计了1台1.5k W实验样机,并进行了实验验证。
Hybrid energy storage system with high power density and high energy density is usually used to maintain the power balance and control the bus voltage in DC microgrid. Based on this background, a multi-resonant three-port DC-DC converter is proposed for usage of hybrid energy storage system in DC microgrid. The LCLC resonant tank has three resonant frequencics, by parameters design, the three resonant frequencies are: two series resonant frequencies of fundamental and third order and a second order parallel resonant frequency. The resonant tank can transfer power of fundamental and third order, and this will increase efficiency of the converter. At the same time, the turn offcurrent of the switches in light load is improved, and the ZVS soft switch range is expanded in light load. Besides, by adjusting the operating frequency along with the load variations, the desirable ZVS characteristics are guaranteed for all the three-port switches. Therefore, lower switching loss and high efficiency are achieved in full load range. Power transfer is managed by controlling the phase shift angles among three ports. At last, a 1.5kW prototype is built to verify the reliability and feasibility of the proposed topology.
出处
《供用电》
2018年第1期14-20,共7页
Distribution & Utilization
基金
国家高技术研究发展计划(863计划)资助(2015AA050603)~~
关键词
直流微电网
混合储能
三端口变换器
多谐振
软开关
DC microgrid: hybrid energy storage: three-port converter, multi-resonant
soft switching