摘要
调制策略是三电平NPC变换器安全可靠运行的关键技术.传统载波调制策略存在中点电位不平衡问题.通过建立三电平NPC两相旋转坐标系下数学模型,对层叠载波调制技术进行分析,针对中点电位不平衡问题,给出抑制中点电位不平衡零序电压的选取原则,提出了注入零序分量的载波调制算法.仿真结果验证了算法的有效性和可行性.
The modulation strategy of three-level NPC converter is one of most important issues for ensu- ring the system reliable operation. The unbalanced neutral point voltage would appear when the conven- tional carrier modulation is applied. In order to deal with the problem, a carrier modulation based on zero- sequence voltage injection is proposed in the paper. Firstly, the mathematical model of three-level NPC converter is built~ the conventional phase disposition carrier modulation is analyzed and the reasons of un- balanced neutral point voltage are analyzed. The selection principles of zero-sequence voltage are given. Fi- nally, the effectiveness of proposed method is verified by simulation results.
出处
《湖南工程学院学报（自然科学版）》
2015年第4期17-21,共5页
Journal of Hunan Institute of Engineering(Natural Science Edition)
基金
湖南省教育厅科研资助项目(15K032)
关键词
三电平逆变器
中点平衡
零序电压
并网控制
载波调制
three-level inverter
neutral point balance
zero-sequence voltage
grid-connected control
carrier modulation
