考虑直流断路器的VSC-MTDC系统鲁棒阻尼控制器设计  

Design of Robust Damping Controller for VSC-MTDC System Considering DC Circuit Breaker

作　　者：马文忠[1] 周冠宇[1] 孙鹏[1] 古丽帕丽·赛力江 张子昂 董磊[1] MA Wenzhong;ZHOU Guanyu;SUN Peng;SAILIJIANG Gulipali;ZHANG Zi'ang;DONG Lei(College of New Energy,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)新能源学院,山东省青岛市266580

出　　处：《电力系统自动化》2020年第6期84-90,共7页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51777216);山东省自然科学基金资助项目(ZR2018MEE040,ZR2019MEE094)。

摘　　要：直流断路器是多端柔性直流输电(VSC-MTDC)系统清除直流故障的关键设备。目前大多数直流断路器系统需要串联直流电抗器以限制故障电流变化率,而大容量直流电抗器与线路串联会抑制直流系统的阻尼,降低多端直流系统的稳定性。文中建立了含直流断路器的VSC-MTDC系统的小信号数学模型,并使用模态分析方法分析了影响系统稳定性的主要因素;针对断路器系统导致的稳定性问题,设计了基于H_∞混合灵敏度理论的阻尼控制器以改善系统的弱阻尼特性。在MATLAB/Simulink中搭建了四端VSC-MTDC模型进行了仿真分析,时域仿真和特征值分析结果证明所提控制方法可以有效抑制直流系统振荡,提高系统稳定性,且相较于其他传统阻尼控制器,更适合系统存在较强扰动和不确定性的情景。DC circuit breaker(DCCB) is a key device for clearing DC faults in voltage source converter based multi-terminal DC(VSC-MTDC) system. Most DCCB systems require to connect DC reactor in series to limit the rising rate of the fault current, but large-capacity DCCB connecting DC reactor in series could decrease the damping of DC system and reduce the stability of multiterminal DC system. In this paper, a small-signal mathematical model for VSC-MTDC system with DC breakers is constructed and modal analysis is performed to illustrate the main factors which could affect the system stability. To solve the stability problem caused by the circuit breaker system, a damping controller based on H_∞ hybrid sensitivity theory is designed to improve the weak damping characteristics of the system. Finally, with a four-terminal VSC-MTDC model implemented in MATLAB/Simulink,time-domain simulation and eigenvalue analysis results show that the proposed approach can efficiently suppress the DC system oscillations and improve the system stability. Compared with other traditional damping controllers, it is more applicable in scenarios with strong disturbances and uncertainties.

关 键 词：多端柔性直流输电 混合灵敏度 H_∞控制 模态分析 阻尼控制 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM561