摘要
基于绝缘栅双极型晶体管(IGBT)的桥臂切换多电平换流器(A2MC)直流电压利用率高,可以在直流侧短路时继续运行,但IGBT耐压低、损耗大、成本高。文中用晶闸管替换A2MC中的IGBT,构成一种混合型多电平换流器(HMC),在保持A2MC优点的同时降低了成本。在分析HMC拓扑及其工作原理的基础上,研究了该换流器正常运行状态下的控制策略,采用最近电平逼近调制并提出了适用于级联H桥的电压均衡控制策略;探讨了直流侧短路故障时的控制方法,并对该换流器与模块化多电平变流器(MMC)的功率器件数和工作性能进行了比较;利用PSCAD/EMTDC对61电平HMC进行了建模仿真,结果验证了其拓扑的可行性与控制策略的有效性。
With high DC voltage utilization rate,an alternate-arm multilevel converter（A2MC） based on insulated gate bipolar transistors（IGBTs） has DC fault blocking capability.Given that IGBTs are low in withstanding voltage with high loss and high cost,the IGBTs used as switches in A2MC are replaced by silicon controlled rectifiers（SCRs）,thus,a hybrid multilevel converter（HMC） is put forward to reduce cost without losing its advantages.This paper introduces the topology and working principle of a HMC.The nearest voltage level（NVL） modulation and balance control of H-bridge modules are proposed.Power components number,components quantity and fault blocking capability are compared between modular multilevel converter（MMC） and HMC control strategy of HMC on DC fault condition is studied.The 61-level model of HMC is set up in PSCAD/EMTDC.The feasibility and effectiveness of proposed HMC and control strategy are verified according to the simulation.
出处
《电力系统自动化》
EI
CSCD
北大核心
2012年第21期102-107,共6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(2008AA05Z213)~~
关键词
多电平换流器
电路拓扑
最近电平逼近法
电压均衡控制策略
multilevel converter
circuit topology
nearest voltage level（NVL）
voltage balancing control strategy
