摘要
新能源在现代电力系统中的逐步渗透正造成愈发严重的稳定问题。构网变流控制因其在改善系统安全方面的独特优势,正成为新能源大规模并网的主流控制方法。因此,本文提出了一种用于构网型变流器的基于虚拟磁链定向的滑模控制策略,使变流器具备虚拟同步机特性以支撑新能源安全并网与同步运行。首先,定义了构网变流器虚拟磁链的概念,其为电压源变流器端电压对时间的积分,并通过一个磁链控制器,将虚拟磁链矢量定向为虚拟同步机摇摆方程的参考轴系,进而实现变流器并网同步。此外,针对虚拟磁链提出了一种滑模控制器,进而实现对电压源型变流器有功/无功功率和电压的控制。为防止电网故障下变流器过电流的发生,本文又提出了一种故障电流抑制方法以提高系统的低电压穿越能力。最终,通过RTDS半实物仿真验证了本文所提控制方法的有效性。
The gradual penetration of new energy into the modern power system is causing more severe stability issues.Due to the unique merits in enhancing the system stability,grid forming control is becoming one of the mainstream control approaches in large scale integration of renewable power.Therefore,this paper aims to propose a novel sliding mod control method for grid-forming converters via the virtual flux orientation,which enables the converters with the characteristics of virtual synchronous generator to support grid integration and synchronized operation of renewable energy.First of all,the concept of virtual flux for the grid-forming converter is proposed,which is denoted by the time integral of the voltage source converter(VSC)terminal voltage.Via a virtual flux controller,the virtual flux is reoriented to the reference axis of the swing equation of the virtual synchronous generator,thereby the grid synchronization is achieved.Moreover,the proposed virtual flux reorientation scheme is capable of controlling the active/reactive power and voltage of the VSC.To prevent the overcurrent of the converters during grid fault condition,this paper also proposed a short circuit current limiting approach to enhance the low voltage ride through capability of the system.Finally,the effectiveness of the proposed method is validated in RTDS simulation platform.
作者
陈兵
李群
王旭
朱银方
郭世威
熊林云
CHEN Bing;LI Qun;WANG Xu;ZHU Yinfang;GUO Shiwei;XIONG Linyun(State Grid Jiangsu Electric Power Co.,Ltd.Research Institute,Nanjing 211103,China;School of Electrical Engineering,Chongqing University,Chongqing 400044,China)
出处
《电工电能新技术》
CSCD
北大核心
2024年第10期102-112,共11页
Advanced Technology of Electrical Engineering and Energy
基金
国网江苏省电力有限公司科技项目(J2022161)。
关键词
构网型变流器
虚拟磁链定向
电流限幅器
并网同步运行
grid-forming converter
virtual flux orientation
current limiter
grid synchronization
