面向直流微电网的混合级联多电平逆变器阶梯波控制策略研究  

Staircase control strategy of hybrid Cascaded Multilevel Inverter for DC micro grid

作　　者：桑子夏 颜炯 雷何 杨洁 王丹[2] 黄家祺 SANG Zixia;YAN Jiong;LEI He;YANG Jie;WANG Dan;HUANG Jiaqi(Economic&Technology Research Institute,State Grid Hubei Electric Power Co.,Ltd,Wuhan 430077,China;School of Electrical and Electronic Engineering of Huazhong University of Science and Technology,Wuhan 430072,China)

机构地区：[1]国网湖北省电力有限公司经济技术研究院规划评审中心,武汉430077 [2]华中科技大学电气与电子工程学院,武汉430072

出　　处：《中南民族大学学报（自然科学版）》2024年第5期660-666,共7页Journal of South-Central University for Nationalities：Natural Science Edition

基　　金：国网湖北省电力有限公司科技项目(521538220008)。

摘　　要：级联多电平变换器将数个全桥逆变模块以级联方式进行连接并予以控制,适用于中压大功率输出场景下的直流微电网,广泛应用于能量路由器、智能电能网关、固态变压器等电力电子装置中.传统级联多电平变换器所级联的每一路逆变模块的电压相同,限制了多电平输出电压的电平数量.为解决上述问题,将传统的母线电压相等的三路级联7电平逆变器改造成母线电压为2的倍数关系(20∶21∶22)的三路混合级联15电平逆变器,通过采用阶梯波控制方法,并针对最近电平逼近法进行了改良以产生开关器件的触发信号,可有效降低开关器件的开关频率和开关损耗,并将输出电压由7电平增加到15电平,有效降低谐波.从混合级联15电平逆变器工作原理、阶梯波调制方法、输出电压谐波等角度开展了理论分析与计算,最终搭建样机进行实验,有效验证了所提出的分析和研究.Cascaded Multilevel Inverter(CMLI)which consists of several H-bridge inverter modules for medium-voltage high-power DC micro grid is widely applied on the power electronic devices including energy router,intelligent energy hub and static transformer.The traditional CMLI has the same DC bus voltage for each H-bridge inverter modules,which reduces the number of voltage levels of the output.By applying voltage ratio of the DC bus voltage from 1∶1∶1 to 20∶21∶22 for a traditional 7-level 3H-bridge inverter,the proposed inverter operates with 15-level resolution.By applying staircase control and the modified nearest level modulation,the switching frequency,the switching power loss and the total harmonics distortion of output voltage to the proposed hybrid cascaded inverter are reduced effectively.The theoretical analysis and calculation on the working principle,staircase control and output voltage harmonics for the proposed hybrid cascaded 15-level inverter are presented,and a laboratory prototype of a 15-level IGBT-based CMLI is designed and implemented for the verification.

关 键 词：级联多电平 阶梯波调制方法 混合级联 直流微电网 

分 类 号：TM921.52[电气工程—电力电子与电力传动]