摘要
提出了一种改进式模块化多电平换流器(MMC)快速仿真方法,与已有的模块化多电平换流器快速仿真方法相比,其改进体现在能够精确地对MMC闭锁状态下的桥臂进行模拟。改进式MMC快速仿真方法利用一个等效子模块替代一个桥臂,在MMC非闭锁情况下,桥臂等效为一个戴维南等效电路,与已有的MMC快速仿真方法相似;而在MMC闭锁情况下,桥臂将被等效为一个具有集中参数的半桥不控子模块。在PSCAD/EMTDC仿真软件中进行二阶段启动以及直流线路故障的仿真验证,已有的MMC快速仿真方法在处理MMC闭锁问题时由于未考虑二极管的插值问题,具有较大的计算误差,而所提出的改进式MMC快速仿真方法,很好地解决了二极管的插值问题,具有较高的仿真精度。
This paper proposes an improved fast model for the modular multilevel converter (MMC) which, compared with existing fast models, is capable of accurately simulating the converter arm with DC converter blocked. The proposed fast model replaces the converter arm with an equivalent sub-module. Under un-blocked simulation, the converter arm can be treated as a Thevenin' s equivalent circuit, which is similar to the existing fast model. While under the DC converter blocked condition, the converter arm is simplified as an uncontrollable sub-module with lumped parameters. Two-stage start-up simulation and DC line fault simulation are carried out to verify the accuracy of the improved fast model. By comparison, the existing fast model has appreciable computational errors under DC blocked simulation because of the negligence of interpolation of diodes. However, the proposed improved fast model, which takes the interpolation of diodes into account, has very good accuracy under DC blocked simulation.
出处
《电力系统自动化》
EI
CSCD
北大核心
2014年第24期56-61,85,共7页
Automation of Electric Power Systems
基金
国家高技术研究发展计划(863计划)资助项目(2012AA051704)~~
关键词
模块化多电平换流器
电磁暂态仿真
等效建模
换流站闭锁
二极管插值
启动仿真
直流故障仿真
modular multilevel converter
electromagnetic transient simulation
equivalent modeling
DC blocking of theconverter
interpolation of diodes
start-up simulation
DC line fault simulation