三电平逆变器低共模电压调制算法的研究  

Research on low common mode voltage modulation algorithm of three-level inverters

作　　者：吕嘉俊 罗利文[1] LV Jiajun;LUO Liwen(Key Laboratory of Control of Power Transmission and Conversion(SJTU),Ministry of Education,Shanghai Jiao tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学电力传输与功率变换控制教育部重点实验室,上海200240

出　　处：《电气应用》2023年第6期74-83,I0004,共11页Electrotechnical Application

摘　　要：为了降低三电平逆变器输出共模电压,首先提出了一种改进的三电平逆变器调制算法,该方法通过弃用传统N3V调制算法中引起高共模的基本电压矢量,将传统的七段式N3V SVPWM调制算法改为五段式SVPWM调制算法。这种改进的五段式N3V SVPWM调制算法可将三电平逆变器输出共模电压降低50%,开关损耗降低1/3。考虑到五段式N3V SVPWM调制算法会导致中性点电位偏移,设计了一种九段式调制算法,仍然规避使用引起高共模的基本电压矢量,通过引入虚拟矢量来调节流入和流出中性点电流达到平衡,避免了中性点电位偏移,同时有效抑制了三电平逆变桥输出共模电压的幅值。To reduce the output common mode voltage of three-level inverters,this paper first proposes an improved three-level inverter modulation algorithm,which changes the traditional seven-segment N3V SVPWM modulation algorithm to five segment SVPWM modulation algorithm by discarding the basic voltage vector that causes high common mode.This improved five-segment N3V SVPWM modulation algorithm can reduce the output common mode voltage of the three-level inverter by 50% and the switching loss by 1/3.Considering that the five-segment SVPWM N3V modulation algorithm will lead to the midpoint potential oscillation,a nine-segment virtual vector modulation algorithm is designed,which still avoids using high CMV vectors.The virtual vector is introduced to adjust the inflow and outflow midpoint current to achieve balance,which avoids the midpoint potential oscillation,and also effectively suppresses the amplitude of the three-level inverter bridge output common mode voltage.

关 键 词：三电平逆变器 共模电压 空间矢量调制 虚拟矢量 中性点电位平衡 

分 类 号：TM464[电气工程—电器]