基于PLL同步的弱连接VSC在严重电网故障下的解析注入电流稳定域构建  

Construction of Analytical Injected Current Transient Stability Region in Weak Gridconnected VSC Based on PLL Synchronization Under Severe Grid Faults

作　　者：郝晓光 李剑锋 王智[2] 李霞林[2] HAO Xiaoguang;LI Jianfeng;WANG Zhi;LI Xialin(Energy Control Technology Research Institute,State Grid Hebei Energy Technology Service Co.,Ltd,Shijiazhuang 050000,China;Key Laboratory of Smart Grid of Ministry of Education(Tianjin University),Tianjin 300072,China)

机构地区：[1]国网河北能源技术服务有限公司能源控制技术研究所,石家庄050000 [2]智能电网教育部重点实验室(天津大学),天津300072

出　　处：《电力系统及其自动化学报》2023年第5期145-151,共7页Proceedings of the CSU-EPSA

基　　金：国网河北能源技术服务有限公司2021年科技项目(TSS2021-05)。

摘　　要：针对弱连接条件下锁相环同步电压源变流器WG-VSC(weak grid connected voltage source converter)系统的暂态同步稳定问题,首先建立了适用于分析WG-VSC系统在严重电网故障期间的锁相环同步暂态稳定问题的等效转子摇摆方程模型。然后利用改进的等面积定则I-EAC(improved equal area criterion)揭示了弱连接条件下VSC并网系统在严重电网故障下的暂态同步失稳机理;在此基础上,给出了系统在严重电网故障等大扰动下的保证系统暂态稳定的注入电流暂态稳定域的解析边界,为故障期间注入电流策略的制定提供了理论依据。最后,在PSCAD/EMTDC搭建了WG-VSC系统的详细开关模型,仿真结果验证了等效转子摇摆方程模型以及注入电流稳定域的有效性。To solve the phase-locked loop(PLL)transient synchronization stability problem of a weak grid-connected voltage source converter(WG-VSC)system under weak connection conditions,an equivalent rotor swing equation mod⁃el which is applicable for analyzing the PLL transient synchronization stability problem of the WG-VSC system under se⁃vere grid faults is established at first.Then,the improved equal area criterion(I-EAC)is used to reveal the transient synchronization destabilization mechanism of the VSC grid-connected system under weak connection conditions and se⁃vere grid faults.On this basis,the analytical boundary of the injection current transient stability region to ensure the sys⁃tem’s transient stability is given,which provides a theoretical basis for the formulation of the injection current strategy under faults.Finally,a detailed switching model of the WG-VSC system is built in PSCAD/EMTDC,and simulation re⁃sults verify the validity of the equivalent rotor swing equation model and ICFR.

关 键 词：暂态同步稳定性 改进等面积定则 注入电流暂态稳定域 

分 类 号：TM46[电气工程—电器]