高压大容量混合型MMC半桥子模块下部IGBT损耗优化方法  

Loss optimization method for bottom IGBT in half bridge sub-module of high voltage and large capacity hybrid MMC

作　　者：韩文超 路茂增 马新喜 赵艳雷[1] 张厚升[1] HAN Wenchao;LU Maozeng;MA Xinxi;ZHAO Yanlei;ZHANG Housheng(School of Electrical and Electronic Engineering,Shandong University of Technology,Zibo 255000,China)

机构地区：[1]山东理工大学电气与电子工程学院,山东淄博255000

出　　处：《电力工程技术》2024年第2期189-198,共10页Electric Power Engineering Technology

基　　金：山东省自然科学基金资助项目(ZR2020QE215);国家自然科学基金资助项目(62073200)。

摘　　要：模块化多电平换流器(modular multilevel converter,MMC)存在器件损耗分布不均的问题,尤其是在逆变工况下,半桥子模块下部绝缘栅双极晶体管(insulated gate bipolar transistor,IGBT)损耗远高于其他器件,导致其热应力与故障率均较高,是制约高压大容量换流器可靠运行的关键因素之一。为此,文中提出一种混合型MMC器件损耗分布优化方法。首先,计算混合型MMC中各器件的损耗,分析器件损耗的分布特性。其次,分析电容电压对器件损耗的影响规律,明确降低半桥子模块电容电压可减少其下部IGBT的损耗。然后,在不影响换流器外输出特性的前提下,提出计及三次谐波电压注入及桥臂输出电压指令值差异化分配的控制策略,通过最大程度降低半桥子模块电容电压,减少其下部IGBT损耗。最后,开展MATLAB/Simulink和PLECS的联合仿真以及MMC样机实验,仿真及实验结果验证了所提方法可以改善混合型MMC损耗分布不均的问题,有利于提高换流器的整体可靠性。Power losses on the upper and bottom insulated gate bipolar transistors(IGBTs)in half bridge sub-modules(HBSMs)are uneven when hybrid modular multilevel converters(MMCs)work as inverters.The loss of the bottom IGBT in HBSM is much higher than any other device,which results in the high thermal stress and failure rate.To address this problem,a device power loss distribution optimization method is proposed in this paper.Firstly,device power losses are calculated,and the distribution characteristic is analyzed.Secondly,the influence of sub-module capacitor voltage on the device power loss is analyzed,and it is found that the loss of the bottom IGBT can be reduced for a low sub-module capacitor voltage.Thirdly,through combining third harmonic voltage injection and the differential distribution of the arm output voltage reference,a loss distribution optimization method based on low sub-module capacitor voltage is proposed.Finally,the simulation and experiment results verify that the proposed method can improve the uneven device loss distribution of hybrid MMC and the operation reliability of the converter.

关 键 词：模块化多电平换流器(MMC) 损耗计算 损耗分布 三次谐波电压注入 桥臂电压差异化分配 低子模块电容电压 

分 类 号：TM721.1[电气工程—电力系统及自动化]