中国电力2024，Vol.57Issue(7)：21-29,9.DOI:10.11930/j.issn.1004-9649.202303126
弱电网下新能源逆变器自同步电压源低电压穿越控制方法
Self-synchronization Voltage Source LVRT Control Method for New Energy Inverter under Weak Grid
摘要
Abstract
The self-synchronization voltage source control technology of the grid-connected inverter is of great significance to the construction of new power system dominated by renewable energy.When the voltage of weak grid drops,the traditional self-synchronization control strategy will have a series of problems in the process of low voltage ride through(LVRT),such as the large transient current impact,the instability of weak grid voltage,and the imbalance of voltage-current control ability,which are caused by the large grid impedance and phase angle difference.For this reason,the relationship between the grid voltage vector and the grid impedance and the grid-connected current in the case of voltage sag under the weak grid,as well as the influencing factors are derived in this paper.Furthermore,a multi-state following self-synchronization voltage source LVRT control method based on stable and transient impedance reshaping is proposed to balance the control ability between voltage and current through steady-state impedance,and ensure the transient control and smooth transition of voltage and current in the whole process through transient impedance reshaping.At the same time,a transient control strategy based on multi-state following is proposed to further ensure the smooth switching and stable operation during the voltage drop and recovery process under weak grid,which can firstly deliver reactive power to support the grid voltage,and compensate the impact of transient overvoltage and overcurrent caused by phase angle and amplitude mutation to help the grid voltage transit smoothly.Finally,the correctness and effectiveness of the proposed control method are verified in MATLAB/Simulink.关键词
弱网/自同步/低电压穿越/暂稳态阻抗重塑/多状态跟随Key words
weak grid/self-synchronization/low voltage ride through/stable and transient impedance reshaping/multi-state following引用本文复制引用
柳丹,江克证,康逸群,冀肖彤,徐韫钰,刘芳..弱电网下新能源逆变器自同步电压源低电压穿越控制方法[J].中国电力,2024,57(7):21-29,9.基金项目
国家电网有限公司科技项目(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). This work is supported by Science and Technology Project of SGCC(Research on Key Technologies of County High Proportion Renewable Energy Power System Operation,No.4000-202122070A-0-0-00). （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）
