MMC-HVDC交直流混联系统小扰动稳定域迭代求解和形态分析  

Iterative Solving and Morphological Analysis of Small-signal Stability Region for Hybrid AC/DC System with MMC-HVDC

作　　者：曹靖洺 董朝宇 王睿[2] 穆云飞[1] 肖迁 贾宏杰[1] CAO Jingming;DONG Chaoyu;WANG Rui;MU Yunfei;XIAO Qian;JIA Hongjie(Key Laboratory of the Ministry of Education on Smart Power Grids(Tianjin University),Tianjin 300072,China;College of Information Science and Engineering,Northeastern University,Shenyang 110819,China)

机构地区：[1]智能电网教育部重点实验室(天津大学),天津市300072 [2]东北大学信息科学与工程学院,辽宁省沈阳市110819

出　　处：《电力系统自动化》2024年第16期40-50,共11页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(52061635103)。

摘　　要：随着高压直流输电技术的发展,区域电力系统将拓展为大规模交直流混联系统。因此,需要建立可以同时精确刻画交直流动态的大规模交直流混联系统模型来研究混联系统的动态与稳定性。文中考虑了交流侧和直流侧的详细动态,建立了异步联网的模块化多电平换流器型高压直流(MMC-HVDC)交直流混联系统的状态空间模型,给出了具体的解析解形式,并推导了多重迭代信赖域算法。所提算法建立了决策变量空间内的点与平衡点的映射关系,结合Hopf分岔识别边界,提出了一种多重迭代求解小扰动稳定域边界的方法。在利用Simulink仿真验证模型准确性后,以发电机出力作为决策变量绘制了交直流混联系统稳定域,利用特征根和参与因子定量研究了直流失稳和交流失稳的机理以及控制策略和控制参数对稳定域边界的影响。对比分析了多区域的混联系统与交流系统的稳定域,结果表明换流站和直流网络的引入可能使多区域系统稳定域边界呈现多约束共同决定的近似分段线性拓扑特性。With the development of HVDC transmission technology,regional power systems will expand into large-scale hybrid AC/DC systems.Therefore,it is necessary to build a large-scale hybrid AC/DC system model that is able to accurately depict both AC and DC dynamics to study the dynamics and stability of the hybrid system.Considering the detailed dynamics from both AC and DC sides,this paper establishes a state-space model of the asynchronously interconnected hybrid AC/DC system with modular multilevel converter based high voltage direct current(MMC-HVDC).The specific analytic solution form is given and a multi-layer iterative trust-region algorithm(MITRA)is derived.The proposed algorithm builds the mapping relation between the points in the decision variable space and the equilibrium points.Combining with the boundary identification based on the Hopf bifurcation,this paper proposes a multi-iteration method for solving the small-signal stability region boundary.After verifying the model accuracy by using the Simulink simulation,the stability region of the hybrid AC/DC system is plotted with the generator output as the decision variable.By using the eigenvalues and participation factors,the mechanisms of DC instability and AC instability as well as the influences of control strategies and parameters on the region boundary are all quantitatively studied.The stability regions of the multi-region hybrid system and the AC system are compared and analyzed.The results show that the introduction of the converter station and the DC network may cause the stability region boundary of the multi-region system to present an approximate piecewise linear topology characteristic determined by multiple constraints.

关 键 词：交直流混联系统 模块化多电平换流器 信赖域算法 稳定域 参与因子 HOPF分岔 

分 类 号：TM721.3[电气工程—电力系统及自动化] TM712