低共模电压三相准单级逆变器空间矢量调制策略  

SVPWM scheme for low common-mode voltage of three-phase quasi-single-stage inverter

作　　者：张犁 马天睿 张涛[1] 王江峰 孙凯[2] ZHANG Li;MA Tianrui;ZHANG Tao;WANG Jiangfeng;SUN Kai(College of Energy and Electrical Engineering,Hohai University,Nanjing 211100,China;Department of Electrical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]河海大学能源与电气学院,江苏南京211100 [2]清华大学电机工程与应用电子技术系,北京100084

出　　处：《电力自动化设备》2022年第2期134-140,共7页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51677054);江苏省六大人才高峰创新团队资助计划(2019-TD-XNY-001)。

摘　　要：由于部分光伏功率可单级传输馈入电网,三相准单级逆变器的变换效率高于传统三相两级式逆变器,但共模电压幅值和频率变化量较高。提出一种适用于三相准单级逆变器的低共模电压空间矢量调制(LCSVPWM)策略,通过舍弃部分小矢量和替换零矢量,降低了共模电压幅值和频率的变化量。此外,通过理论计算,比较了三相准单级逆变器分别采用传统空间矢量调制(CSVPWM)策略和LCSVPWM策略,以及三相两级式逆变器采用七段式空间矢量调制策略这3种情况下的开关管损耗。搭建了一台功率为3 kW的三相准单级逆变器样机。实验结果表明,当输入电压较低时,采用LCSVPWM策略的逆变器共模电压幅值和频率变化量低于采用CSVPWM策略。此外,采用LCSVPWM策略的三相准单级逆变器效率虽略低于CSVPWM策略,但高于三相两级式逆变器,故LCSVPWM策略在效率和共模性能的提升方面均有优势。Since part of the photovoltaic power can be fed to the grid with single-stage power conversion,three-phase quasi-single-stage inverter has higher efficiency than that of conventional three-phase two-stage inverter.However,it still has the issue of high variation of amplitude and frequency of common-mode voltage.A LCSVPWM(Low Common-mode voltage Space Vector Pulse Width Modulation)scheme is proposed to reduce the variation of amplitude and frequency of common-mode voltage by omitting part of small voltage vectors and replacing zero voltage vectors.In addition,by calculating theoretically,the power losses of switching devices in three cases are compared,including the three-phase quasi-single-stage inverter adopting the CSVPWM(Conventional Space Vector Pulse Width Modulation)scheme and LCSVPWM scheme,and the three-phase two-stage inverter adopting seven-segment SVPWM scheme.A prototype of a 3 kW threephase quasi-single-stage inverter is built.Experimental results show that when the input voltage is low,the variation of amplitude and frequency of common-mode voltage of inverter adopting LCSVPWM scheme is lower than that adopting CSVPWM scheme.In addition,the efficiency of the three-phase quasi-single-stage inverter adopting LCSVPWM scheme is slightly lower than that adopting CSVPWM scheme,but higher than that of the three-phase two-stage inverter.Thus,LCSVPWM scheme has advantages in improving both efficiency and common-mode performance.

关 键 词：逆变器 共模电压 空间矢量调制策略 光伏 效率 

分 类 号：TM464[电气工程—电器]