基于等效同步功率的孤岛并联构网变流器系统暂态稳定性分析  

Transient Stability Analysis of Islanded System with Parallel Grid-forming Converters Based on Equivalent Synchronous Power

作　　者：邹赵悦 吴超 王勇[1] 田杰[2] 詹长江 ZOU Zhaoyue;WU Chao;WANG Yong;TIAN Jie;ZHAN Changjiang(School of Electrical and Information Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;NR Electric Co.,Ltd.,Nanjing 211102,China)

机构地区：[1]上海交通大学电子信息与电气工程学院,上海市200240 [2]南京南瑞继保电气有限公司,江苏省南京市211102

出　　处：《电力系统自动化》2024年第2期140-150,共11页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(52207063)。

摘　　要：随着构网变流器在微电网中应用的增长,其对微电网暂态稳定的影响受到了广泛关注。不同于单机无穷大系统,孤岛并联构网变流器系统的频率和功角差相互耦合,暂态响应特性更为复杂。为精准分析孤岛并联构网变流器系统的暂态响应,文中基于功角耦合运动方程建立双机频率和功角差的三阶暂态同步模型,并且分析了双机出力差异和下垂系数对于暂态稳定的影响特征。为揭示出力和下垂系数对于暂态稳定的耦合机理,对双机系统进行等效同步功率分析,并且提出一种基于构网变流器出力的自适应下垂系数优化策略,可以根据出力差异自适应提升双机系统的等效同步功率,进而提升系统暂态稳定性。最后,采用实时仿真验证了三阶暂态模型的正确性和所提控制策略的有效性。With the increasing application of grid-forming(GFM)converters in the microgrid,the effects of GFM converters on the transient stability of the microgrid have received extensive attentions.Different from the single-machine infinite bus system,the frequency and power angle of the islanded system with parallel GFM converters are coupled with each other,and the transient response characteristics are more complex.In order to accurately analyze the transient response of the islanded system with parallel GFM converters,this paper establishes a three-order transient synchronization model of frequency and power angle difference of two GFM converters based on the power angle coupling equation of motion,and analyzes the characteristics of the influence of the power output difference and droop coefficients of two GFM converters on the transient stability.In order to reveal the coupling mechanism of power output and droop coefficient on transient stability,the equivalent synchronous power of parallel GFM converters is analyzed.An adaptive droop coefficient optimization strategy is also proposed based on the power output of GFM converters,which can adaptively increase the equivalent synchronous power of the parallel system and thus improve the transient stability of the system.Finally,the real-time simulation is used to verify the correctness of the three-order transient model and the effectiveness of the proposed control strategy.

关 键 词：构网变流器 孤岛微电网 暂态稳定性 相平面分析 等效同步功率 自适应下垂系数 

分 类 号：TM46[电气工程—电器] TM712