摘要
模块化多电平换流器的启动是系统正常运行的前提和基础,也是柔性直流输电系统运行过程中的重要环节。换流器交流侧为无源网络或待启动的有源网络时,启动过程需要增加辅助电源,增加成本和工作量。提出一种直流侧充电启动方法,通过不控整流预充电后子模块数递减方法解锁使子模块电容电压达到预先设定值,无需增加辅助电源,能有效限制充电过程中的电压和电流冲击。在PSCAD/EMTDC中搭建两端柔性直流输电系统模型,验证了该方法的可行性和有效性。
The startup of the modular multilevel converter(MMC)is not only the premise and foundation for the normal operation but also an important part of the flexible DC power transmission system. When the AC side of the converter is connected to the reactive network or to the active network which has yet to be started up,auxiliary power supply should be added in the startup,thus increasing the cost and work load.This paper presents a method to start up and charge from the DC side,which uses the uncontrollable rectifier pre-charge strategies and sub-module descending method to charge the voltage of sub-module capacitors to the preset value without adding auxiliary power supply. This method can also effectively limit the voltage and current surge in the charging process. The feasibility of the method is verified by two terminals VSCHVDC models established in the PSCAD/EMTDC.
出处
《电网与清洁能源》
2014年第10期8-12,共5页
Power System and Clean Energy
基金
国家高技术研究发展计划(863计划)(2011AA05A102)~~
