摘要
为了改善并联系统在不平衡工况下出现的输出电压不平衡、功率不均分的问题,提出了一种针对三相四桥臂逆变器的分序控制方法;同时,为了削弱三相四桥臂这种带中线的系统固有的共模电压干扰问题,采用了高频链矩阵式三相四桥臂的拓扑结构。由于系统中的零序分量全部流经第四桥臂,故可将第四桥臂与前三桥臂分开进行独立控制;为了实现并联系统各逆变器的容量匹配,提出在前三桥臂上采用两相静止坐标系下无耦合的虚拟阻抗相匹配的下垂控制,而第四桥臂采用独立虚拟电阻控制的方案。与传统方案相比,该方案优化了虚拟阻抗设计结构的同时解除了各坐标轴间的耦合,方便了闭环控制器的设计,同时还能在一定程度上滤除电流噪声,提高输出电压质量。最终可在实现不平衡工况下并联高频链矩阵式三相四桥臂逆变器系统输出电压平衡的同时按容量分配负载消耗的功率。仿真和实验验证了该方法的可行性和正确性。
To improve the unbalanced output voltage and uneven power sharing of the parallel system under unbalanced conditions,a new sequential control method for three-phase four-leg inverter is proposed.Also,in order to weaken inherent common mode interference problem of three-phase four-leg inverter,which needs a neutral line,a high-frequency link matrix three-phase four-leg topology is used.Since the zero-sequence current in the system all flow through the fourth leg,the fourth leg and the other three legs can be separately controlled independently;In order to realize the capacity allocation of the parallel inverters,a virtual impedance matching drooping scheme without coupling under two-phase stationary coordinate is proposed for the first three bridge arms,while a separate virtual resistor control scheme used by the fourth bridge.Compared with the traditional one,The proposed control scheme optimizes the design structure of virtual impedance,removes the coupling between the axes and facilitates the design of the closed-loop controller.Also filters the current noise in some extent and improves the output voltage quality.Finally,it realizes a balanced output voltage and a sharing load power by capacity in the system of parallel high-frequency link matrix three-phase four-leg inverter under unbalanced conditions.The experiment and simulation results verify the correctness and feasibility of the proposed method.
作者
闫朝阳
孙喆
宋雪微
李建霞
杨丽君
Yan Zhaoyang;Sun Zhe;Song Xuewei;Li Jianxia;Yang Lijun(Key Lab of Power Electronics for Energy Conversion and Motor Drive of Hebei Province,Yanshan University,Qinhuangdao 066004,China)
出处
《电工技术学报》
EI
CSCD
北大核心
2019年第S02期560-572,共13页
Transactions of China Electrotechnical Society
基金
国家自然科学基金面上(61671403、61573320)
国家重点研发计划(2016YFC0802900)资助项目
关键词
不平衡工况
高频链矩阵式逆变器三相四桥臂并联
下垂控制
分序控制
Unbalanced condition
parallel of high-frequency link matrix three-phase four-leg inverter
droop control
sequence control
