基于混合型MMC全桥子模块比例的直流侧故障隔离电压研究  

Research on DC Fault Isolation Voltage Based on Proportions of Full Bridge Sub-modules of Hybrid MMC

作　　者：邓帅荣 周念成[1] 王月月 练睿 冉立[1] DENG Shuairong;ZHOU Niancheng;WANG Yueyue;LIAN Rui;RAN Li(State Key Laboratory of Power Transmission Equipment ＆ System Security and New Technology,Chongqing University,Chong-qing 400030,China;State Grid Chengdu Electric Power Supply Company,Chengdu 610000,China)

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030 [2]国网成都供电公司,成都610000

出　　处：《高电压技术》2018年第10期3250-3257,共8页High Voltage Engineering

基　　金：国家重点研发计划(2016YFB0901801)~~

摘　　要：混合型模块化多电平变流器（MMC）相比于传统MMC,是一种更新颖的直流换流器拓扑结构。该结构同时包含了全桥子模块和半桥子模块,相应地同时具有全桥子模块隔离直流侧双极短路故障的优势和半桥子模块的经济性。为此,研究了不同全桥子模块比例的混合型MMC隔离直流侧短路故障的能力,通过分析短路故障状态下的等效电路图,推导出全桥子模块电容的故障隔离电压值,在此基础上推导出了能有效隔离直流侧双极短路故障的混合型MMC全桥子模块比例的临界值的计算公式。最后PSCAD仿真验证了上述分析结果,证明合理地选择全桥子模块的比例对节约混合型MMC的成本和改善其隔离直流故障的能力,具有实际意义。Compared to traditional Modular Multilevel Converter（MMC）,Hybrid Modular Multilevel Converter is a newer DC converter topology. The topology includes both full bridge sub-modules and half bridge sub-modules. Consequently, the advantages of the full bridge sub-module isolation DC side bipolar short-circuit fault and the economics of the half-bridge sub-module are simultaneously achieved. We studied the isolating DC side short-circuit faults ability of hybrid MMC with different full bridge sub-modules＇ proportions. The fault isolation voltage value of the full bridge sub-module capacitor was derived by analyzing the equivalent circuit diagram under the short-circuit fault state. Thereby, the formula for calculating the full bridge sub-modules＇ proportion critical value of the hybrid MMC which can effectively isolate the DC side bipolar short-circuit fault was derived. Finally, the above analysis results were confirmed by PSCAD simulation. It can be concluded that the proportion of the full bridge sub-module which is designed reasonably has practical significances for saving the cost of the hybrid MMC and improving its ability to isolate DC faults.

关 键 词：混合型MMC 子模块比例 直流配电网 直流侧双极短路故障 故障隔离 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM46