基于双Buck电路的改进MMC变换器研究  

Research on Improved MMC Converter Based on Dual Buck Circuit

作　　者：马覃峰 邵震霞[2] 欧阳可凤 王寅 肖建民[2] 沈刚[2] 

机构地区：[1]贵州电网有限责任公司电力调度控制中心,贵阳550002 [2]南京南瑞继保电气有限公司,南京211102

出　　处：《南方电网技术》2017年第11期34-40,共7页Southern Power System Technology

摘　　要：模块化多电平变换器(modular multilevel converter,MMC)在高压大功率场合具有广泛应用前景,但其拓扑结构中存在桥臂直通导致的电容短路等隐患。设计了一种基于双Buck电路的MMC变换器,即以双Buck电路而非桥式电路作为MMC变换器的基本单元。基于双Buck电路的MMC变换器消除了桥臂直通和体二极管反向恢复问题。对该拓扑的工作原理及运行方式进行了分析,给出一种基于最大(小)值电容排序投切的控制方法,以实现电容电压的均衡控制,并在Saber平台上进行了建模仿真,仿真结果与理论分析相符,提高了系统的稳定性。Modular multilevel converter（ MMC） converter is widely used in the application of high voltage large power scenarios,but the shoot-through problem in bridge topology places MMC converter at a serious risk of capacitor short-circuit. A novel MMC converter based on dual buck circuit is designed,where the base cell of the MMC converter is not bridge circuit but dual buck circuit. MMC converter based on dual buck circuit eliminates the risk of shoot-through and reverse-recovery of body diode. The details of working principle and operating modes are analyzed. Control method based on switching of capacitor with maximum（ minimum） capacitance sequence is given to realize the balancing control of capacitance voltage. Simulation results on Saber are identical with the theory,which verifies the stability of the system can be improved.

关 键 词：MMC变换器 双Buck电路 桥臂直通 电容投切 

分 类 号：TM743[电气工程—电力系统及自动化]