含电容单元的级联H桥七电平调制策略  

Seven-level modulation strategy of cascaded H-bridge with capacitor unit

作　　者：顾军[1] 张维国 卜荣荣 李平[1] 张明 杜治斌 GU Jun;ZHANG Weiguo;BU Rongrong;LI Ping;ZHANG Ming;DU Zhibin(School of Electrical and Information Engineering,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学电气与信息工程学院,安徽淮南232001

出　　处：《电力自动化设备》2023年第8期126-132,共7页Electric Power Automation Equipment

基　　金：安徽省自然科学基金资助项目(2108085ME180)。

摘　　要：针对传统三单元级联H桥直流电源电压利用率较低的问题,采用电容替代其中利用率较低的直流电源,构成含电容单元的级联H桥逆变器。围绕该型逆变器的调制策略及电容选择等问题,在载波层叠式脉宽调制策略的基础上,利用冗余开关状态改进现有调制策略。通过采集电容电压和输出电流,切换调制模式实现电容充放电控制。分析电容电荷量在不同调制度下的变化,得到电容电压稳定到参考值所需要满足的条件。考虑到电容纹波电压不超过参考值10%的要求,并结合最大连续放电区间,计算出最小参考电容,使逆变器达到最优配置。通过仿真和实验证明了新型调制策略可对电容充电并具有良好的稳压效果。In view of the problem for low utilization rate of traditional three-element cascaded H-bridge DC power supply voltage,a cascaded H-bridge inverter with capacitor unit is constructed by replacing the DC power supply with low utilization rate.Around the modulation strategy and capacitor selection of this inver-ter,based on the carrier stacked pulse width modulation strategy,the redundant switching pattern is used to improve the existing modulation strategy.By collecting capacitor voltage and output current,the modulation mode is switched to realize capacitor charge and discharge control.The changes of capacitor charge under different modulation switching are analyzed,and the conditions for the capacitor voltage to be stable to the reference value are obtained.Considering the requirement that the ripple voltage of capacitor does not exceed 10%of the reference value and combined with the maximum continuous discharge interval,the minimum reference capacitor is calculated to make the inverter reach the optimal configuration.Through simulation and experiment,it is verified that the new modulation strategy can charge the capacitor and has good voltage stabilization effect.

关 键 词：多电平逆变器 级联H桥 电容单元 调制策略 电容电压控制 

分 类 号：TM464[电气工程—电器]