摘要
寻找一种可有效处理直流侧故障的拓扑结构是目前电压源换流器型高压直流输电(VSC-HVDC)工程应用中的关键性问题。桥臂交替导通多电平换流器(AAMC)具有能够处理直流故障、模块电容数量少、占地空间小等优点,具有广阔的发展前景。针对目前AAMC有关主回路参数确定运维控制等内容有关文献研究不多的情况,首先对AAMC拓扑结构和基本原理进行研究和分析,推导了直流电压和交流阀侧电压的最优关系并分析了子模块数量选取原则;其次研究了稳态运行时正弦波形成电路和导通开关协调配合,并提出了基于电压极性选择的子模块均衡策略;接着分析了直流故障下的控制策略,指出故障期间闭锁导通开关中的IGBT,并通过桥臂模块产生负电平利用串联二极管的反向阻断能力能够完成直流熄弧过程。最后在PSCAD/EMTDC搭建15模块AAMC系统模型,仿真结果验证了设计原则和控制策略的有效性。
Recently,it is a key issue for researchers to find a converter with handling dc fault capability in application of voltage-source-converter-based high-voltage direct current（VSC-HVDC）. The alternate-arm multilevel converter （AAMC） is a new hybrid VSC which brings together some concepts from two-level converter and modular multilevel converter （MMC）. Compared with all in-service VSC topologies, AAMC has many features such as the ability to deal with dc faults, less sub-module capacitors, and smaller footprint, etc. Firstly, we studied its topology and operating characteristics, derived an optimum relationship between dc voltage and ae voltage, and analyzed the number selection principle of sub-module. Then, we researched the coordination between director switch （DS} and wave shaping circuit （WSC）, and proposed a sub-module voltage balancing strategy. Furthermore, we developed a control strategy under dc fault, indicating that dc blocking capacity could be arrived by turning off IGBT of DS and by making WSC to generate negative voltage. Finally, the model of an AAMC with 15 modules per bridge is realized by PSCAD/EMTDC, and the simulation results verify the effectiveness of design principles and control strategies.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2012年第6期1521-1528,共8页
High Voltage Engineering
基金
国家高技术研究发展计划(863计划)(2011AA05A119)~~
关键词
导通开关
全桥子模块
子模块数量选取原则
电容电压平衡控制
电容充放电
直流故障控制
director switch
full bridge cell
number selection of sub-modules
capacitor voltage balancing control
charge and discharge of capacitor
DC fault control
