摘要
虚拟阻抗控制有助于改善构网型变流器因阻性线路引起的功率耦合问题,同时还能在电网发生故障时启动以起到限流作用。虚拟阻抗的引入深刻影响故障大扰动下构网型变流器的暂态同步稳定性,目前尚缺少针对上述影响的稳定量化分析方法。因此,文中首先建立构网型变流器并网系统考虑虚拟阻抗控制前后的经典三阶降阶动态模型。然后,结合拉萨尔不变性原理构建考虑虚拟阻抗功率解耦的改进能量函数。分析表明,改进能量函数能通过吸引域量化评估虚拟阻抗参数对暂态稳定性的影响。基于此,提出一种考虑虚拟阻抗功率解耦的构网型变流器暂态稳定优化控制策略,以提高其暂态同步稳定性。最后,仿真和实验结果验证了所提优化控制策略的有效性。
The virtual impedance control is helpful in reducing the power coupling problem of grid-forming converters caused by resistive lines.It can also be activated to play the role of current limitation in the case of grid fault.The introduction of virtual impedance profoundly affects the transient synchronous stability of grid-forming converters under large disturbances of faults.At present,there is no stable quantitative analysis method for these effects.Therefore,this paper establishes the classical third-order reduced-order dynamic model for the grid-connected system of grid-forming converters with virtual impedance control.Then,an improved energy function considering virtual impedance power decoupling is constructed based on the LaSalle’s invariance principle.The analysis shows that the improved energy function can evaluate the effect of the virtual impedance parameters on the transient stability by quantifying the attraction domain.Based on this,this paper proposes a transient stability optimal control strategy of grid-forming converters considering the virtual impedance power decoupling to improve the transient synchronous stability of grid-forming converters.Finally,the simulation and experimental results verify the effectiveness of the proposed optimal control strategy.
作者
孟潇潇
王煜琛
毛荀
解宝
邵冰冰
MENG Xiaoxiao;WANG Yuchen;MAO Xun;XIE Bao;SHAO Bingbing(Anhui Province Key Laboratory of Renewable Energy Utilization and Energy Saving,Hefei University of Technology,Hefei 230009,China;State Grid Anhui Electric Power Research Institute,Hefei 230000,China)
出处
《电力系统自动化》
EI
CSCD
北大核心
2024年第24期101-111,共11页
Automation of Electric Power Systems
基金
安徽省自然科学基金资助项目(2108085UD09)
国家自然科学基金资助项目(52207087)。
关键词
构网型变流器
暂态稳定
虚拟同步机
虚拟阻抗
功率耦合
能量函数
限流控制
grid-forming converter
transient stability
virtual synchronous generator
virtual impedance
power coupling
energy function
current limiting control
