基于模块化LLC谐振变换器的光伏中压直流并网方案  

Study on MVDC Grid-connected Scheme Based on Modular LLC Resonant Converters for Photovoltaic Energy

作　　者：陈佳玺 江道灼[1] 张翀 胡列翔[2] 陆翌[2] CHEN Jiaxi;JIANG Daozhuo;ZHANG Chong;HU Liexiang;LU Li(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China;State Grid Zhejiang Electric Power Company,Hangzhou 310007,China)

机构地区：[1]浙江大学电气工程学院,杭州市310027 [2]国网浙江省电力公司,杭州市310007

出　　处：《电力建设》2018年第10期44-53,共10页Electric Power Construction

基　　金：国网浙江省电力公司科技项目(5211DS15002W)"直流配电网的工程理论与关键技术研究"~~

摘　　要：与传统光伏大规模接入交流系统和分布式并入低压直流电网的形式不同,面向中压直流配电网的光伏并网系统在传输效率、容量、电压稳定性和电能质量等方面均具有一定的优势,是未来发展直流配电网所需要的一种能源汇集技术。提出了一种适用于中、大容量光伏发电系统接入直流配电网的新型技术方案,设计了并网系统的详细拓扑结构。根据光伏电池特性,设计了发电单元及子模块的参数,并分析了模块化变换器的运行特性。在此基础上,设计了模块化LLC谐振变换器的控制策略,在维持子模块均压均流的同时,实现了对光伏发电单元的最大功率跟踪。最后,通过仿真验证了所设计光伏直流并网方案的可行性和控制系统的有效性。Different from traditional forms large-scale photovoltaic energy integrates into AC network or low-voltage DC grid,photovoltaic power generation connected to MVDC distribution system has some advantages,such as large capacity,higher efficiency,voltage stability and power quality. It is an energy pooling technology needed for the development of DC distribution netw ork in the future. Firstly,a scheme for medium or large capacity photovoltaic power generation system to access DC distribution netw ork is proposed and a topology of the system is designed. Through analysis on the characteristics of photovoltaic cells and the operating characteristics of sub-modules,a new control strategy for modular LLC converter is designed as well as the parameters of generating units and sub-modules. The control system achieves voltage and current sharing and realizes the maximum power tracking of the photovoltaic unit. Finally,the feasibility of the proposed scheme and control system are verified by simulation.

关 键 词：直流配电网 LLC谐振变换器 光伏直流并网 控制系统 

分 类 号：TM615[电气工程—电力系统及自动化]