摘要
并联三电平变换器可满足海上风电对更高容量的需求,但必须采取措施限制并联环流,这里提出了一种兼顾环流抑制和交流谐波的新型一体化调制开关序列。一体化调制将并联变换器视为整体多电平系统,基于多电平矢量空间对所有开关器件的开关状态进行优化分配,可实现显著低于传统交错并联的电流谐波畸变,而且能有效减小并联环流。从一体化调制中多电平状态分配与并联环流之间的关系出发,分析了不同开关序列对环流幅值的影响,利用状态分配过程中的冗余,提出一种新型开关序列,在进一步减小电流谐波的同时,还能大幅降低环流幅值,从而有效解决环流带来的损耗、谐波和滤波器设计等问题。仿真结果和实验波形验证了提出的新型开关序列的有效性。
Parallel three-level converters can meet the demand of offshore wind power system for higher system capacity,but measures must be taken to limit the parellel circulating current.Therefore,a novel switching sequence is proposed to considering of circulating current suppression and alternating current harmonics.The parallel converters are treated as a multi-level system,and the switching state assignment of all switching devices is optimized based on multier-level vector space,which can achieve significantly lower current harmonic distortion than the conventional interleaved paralleling and can effectively reduce the parallel circulating current.Starting from the relationship between multi-level state distribution and parallel circulating current in integrated modulation,the impact of switching sequence on the circulating current is analyzed,and a new switching sequence that can further reduce the circulating current amplitude by using the redundancy in state assignment process is proposed,thus effectively solving the problems of loss,harmonics and filter design caused by circulating current.Simulation results and experimental waveforms verify the effectiveness of the proposed switching sequence.
作者
李伟伟
杨虓
郭春平
张学广
LI Wei-wei;YANG Xiao;GUO Chun-ping;ZHANG Xue-guang(Wuxi University,Wuxi 214105,China;不详)
出处
《电力电子技术》
CSCD
北大核心
2022年第10期33-35,共3页
Power Electronics
基金
国家自然科学基金(51977046)
无锡学院引进人才科研启动专项经费资助(2022r021)
关键词
变换器
三电平
并联环流
环流抑制
converter
three-level
parallel circulating current
circulating current suppression
作者简介
李伟伟(1982-),男,博士,研究方向为新能源功率变换与并网
