弱电网下自同步电压源低电压穿越双模式切换控制方法  

SELF-SYNCHRONIZATION LVRT DUAL-MODE SWITCHING CONTROL METHOD UNDER WEAK GRID

作　　者：柳丹 江克证 康逸群 曹侃 刘芳[2] 徐韫钰 Liu Dan;Jiang Kezheng;Kang Yiqun;Cao Kan;Liu Fang;Xu Yunyu(Electric Power Research Institute of State Grid Hubei Electric Power Co.,Ltd.,Wuhan 430077,China;School of Electrical Engineering and Automation,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]国网湖北省电力有限公司电力科学研究院,武汉430077 [2]合肥工业大学电气与自动化工程学院,合肥230009

出　　处：《太阳能学报》2024年第10期77-85,共9页Acta Energiae Solaris Sinica

基　　金：国家电网公司科技项目(县域高比例可再生能源电力系统运行关键技术研究)(4000-202122070A-0-0-00)。

摘　　要：针对弱电网情况下自同步电压源在低电压穿越时的瞬态过电压和过电流问题,推导电网阻抗、角度跳变、电压跌落深度下的数学方程,并分析影响过电压和过电流的关键因素,进而提出一种自同步电压源低电压穿越(LVRT)双模式切换控制方法,当电网正常运行时采用自同步电压源均衡控制方法,该方法基于虚拟阻抗并通过模拟阻抗来实现平衡电压环和电流环的控制能力;当电网处于电压跌落状态时采用基于强电流控制的LVRT模式,可有效提升电压跌落瞬态、低电压穿越过程以及电压恢复阶段的平滑过渡能力。并提出一种电压恢复控制策略,该控制策略基于多状态反馈跟随器,可有效抑制过渡过程中电压与电流瞬时变化,通过相位突变补偿控制策略抑制瞬态过电流冲击,帮助电网电压恢复。最后,利用Matlab/Simulink建模仿真软件验证该控制方法的可行性和优势性。Aiming at the transient over-voltage and over-circuit problems of self-synchronous voltage source at low voltage ride through(LVRT)in the case of weak grid,this paper derives the mathematical equations of grid impedance,angle jump and voltage drop depth,and analyzes the key factors affecting over-voltage and over-current.Then,a self-synchronous voltage source LVRT dual-mode switching control method is proposed.When the power grid is normal,the self-synchronous voltage source equalization control method based on virtual impedance is used to balance the control strength of the voltage loop and the current loop by simulating the impedance.When the grid is in the state of voltage drop,the low voltage ride through mode based on strong current control can effectively improve the smooth transition ability of voltage drop transient,low voltage ride through process and voltage recovery stage.At the same time,in order to further suppress the voltage and current transients in the transition process,a voltage recovery control strategy based on multi-state feedback follower is proposed,and the transient overcurrent impact is suppressed by the phase mutation compensation control strategy to help the network voltage repair.Finally,the feasibility and superiority of the control method are verified by Matlab/Simulink modeling and simulation software.

关 键 词：自同步电压源 短路比 低电压穿越 虚拟阻抗 状态反馈 

分 类 号：TM46[电气工程—电器]