摘要
NPC型三电平变流器的并联能够增加系统的容量和可靠性,然而当变流器并联运行时,会产生零序环流,零序环流的存在导致传统的统一中点平衡控制法无法实现中点电压的有效控制。为此,本文提出了一种基于有限时间控制的中点电压控制策略,首先分析中点电位不平衡的产生机理,建立中点电压动态方程,设计中点电位有限时间控制器,在考虑零序环流对中点电位影响的基础上,推导中点电压动态系统的有限时间稳定性证明,给出中点电位有限时间控制器的参数选择范围,确定参数大小。通过仿真和实验验证了该策略在并联系统中对中点电压平衡控制的有效性和优良性。
The parallel operation of NPC three-level converters can enhance the system capacity and reliability.How⁃ever,when converters operate in parallel,zero-sequence circulating currents are generated,which prevent the traditional unified neutral-point balancing control algorithm from effectively controlling the mid-point voltage.To address this,this paper proposes a finite-time control strategy for mid-point voltage control.It first analyzes the mechanism of mid-point voltage imbalance,establishes the dynamic equation of the mid-point voltage,and designs a finite-time controller for the mid-point voltage.Considering the impact of zero-sequence circulating currents on the mid-point voltage,it derives the finite-time stability proof of the mid-point voltage dynamic system and provides the parameter selection range for the finite-time controller of the mid-point voltage,determining the size of the parameters.Simulation and experimental results verify the effectiveness and superiority of this strategy in balancing control of the mid-point voltage in parallel systems.
作者
武广爽
李自成
贾佳
余龙海
Wu Guangshuang;Li Zicheng;Jia Jia;Yu Longhai(School of Electrical Information,Wuhan Institute of Technology,Wuhan 430205,China;School of Information Science and Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Dali Electric Xiangyang Co.,Ltd.,Xiangyang 441057,China)
出处
《电力电子技术》
2025年第6期116-121,共6页
Power Electronics
基金
湖北省高等学校优秀中青年科技创新团队计划(T2022012)。
关键词
变流器
并联系统
中点电压
有限时间控制器
converter
parallel system
mid-point voltage
finite-time controller
