模块化多电平换流器子模块短路故障分析、检测与定位方法  

Short-Circuit Fault Analysis, Detection and Location Method for Sub-Modules of Modular Multilevel Converters

作　　者：姜斌 龚雁峰 李岩[1] JIANG Bin;GONG Yanfeng;LI Yan(Department of Electrical and Electronic Engineering, North China Electric Power University, Beijing 102206, China)

机构地区：[1]华北电力大学电气与电子工程学院

出　　处：《南方电网技术》2019年第3期73-78,88,共7页Southern Power System Technology

摘　　要：模块化多电平换流器(modularmultilevel converter,MMC)由大量的子模块串联而成,MCC子模块的运行状态直接影响整个换流站的运行,所以研究MMC子模块的故障特性及故障快速检测与定位方法具有重要意义。本文首先分析了MMC子模块发生短路故障的特性,推导出故障分量的计算公式;然后提出了一种基于MMC子模块电容电压的新型微分欠压检测方法,实现了对MMC故障子模块的检测;最后利用小波变换进行故障IGBT的定位。PSCAD/EMTDC仿真实验表明,本文提出的方法能够准确计算发生MMC短路故障后的IGBT电容电压,并且在不引入额外测量装置的情况下,能快速检测故障子模块并定位故障IGBT,仿真结果验证了本文提出方法的有效性和可靠性。Modular multilevel converter (MMC) consists of a large number of sub-modules (SMs), the operation of which, has direct influence on the total converter substation. So research on the fault characteristic, fast detection and location of the sub-modules are of great significance. In this paper, firstly, the characteristics of MMC SMs short-circuit fault are analyzed and the calculating formula of fault component is deduced, then a method is proposed. Moreover, a novel differential under-voltage detection method is proposed based on SM detection capacitor voltage. Finally, the specific faulty IGBT location is carried out by wavelet transform. Simulations in PSCAD/EMTDC reveal that the proposed method in this paper can calculate accurately the IGBT capacitor voltage after the short-circuit fault of MMC, detect the faulty SM and locate the faulty IGBT precisely and rapidly, which verify the effectiveness and feasibility of the proposed method.

关 键 词：模块化多电平换流器(MMC) 子模块短路 故障子模块检测 新型微分欠压 故障IGBT定位 

分 类 号：TM721[电气工程—电力系统及自动化]