摘要
针对离网工况下带不平衡负载时引起的波动,利用三相四桥臂拓扑结构在不平衡系统应用中的优势,结合虚拟同步机控制策略,采用基于全通滤波器的正负序分离方法进行控制。针对真实输出的有功功率对功频调节器产生波动及多逆变器并联时功率均分及环流抑制效果较差的问题,引入虚拟阻抗,改进了基于正负序分离的虚拟同步机并联预同步控制策略。结果表明,所提控制策略器能够在负载不平衡的情况下维持输出电压的平衡,提高了功率均分精度,使环流得到抑制,增强离网条件下的运行性能。
In view of the fluctuations caused by unbalanced load under off-grid conditions,the advantages of three-phase four leg topology in the application of unbalanced system are applied,combined with the control strategy of virtual synchronous machine,and the positive and negative sequence separation method based on all-pass filter is adopted to control.Aiming at the problems that the real output of active power will fluctuate the power frequency regulator and the power equalization and circulating current suppression effect is poor when multiple inverters are connected in parallel,a virtual impedance is introduced,improved parallel pre synchroniza⁃tion control strategy for virtual synchronous machines based on positive and negative sequence separation.The results show that the proposed control controller can maintain the balance of output voltage under unbalanced load,improve the power equalization accura⁃cy,suppress the circulation current,and enhance the operating performance under off-grid conditions.
作者
卜慎慎
BU Shenshen(College of Intelligent Science and Engineering,Hubei Minzu University,Enshi 445000,China)
出处
《通信与信息技术》
2024年第2期59-63,共5页
Communication & Information Technology
关键词
不平衡负载
三相四桥臂拓扑结构
虚拟同步机
虚拟阻抗
并联预同步
Unbalanced load
Three-phase four-leg topology
Virtual synchronizer
Virtual impedance
Parallel pre-synchro⁃nization
