基于负载变流器控制带宽的直流系统稳定性分析  

Stability Analysis of DC System Based on Control Bandwidth of Load Converter

作　　者：卢浩 朱琳[1,2] 赵学深 郭力 李霞林[1,2] 王成山 LU Hao;ZHU Lin;ZHAO Xueshen;GUO Li;LI Xialin;WANG Chengshan(Key Laboratory of the Ministry of Education on Smart Power Grids(Tianjin University),Tianjin 300072,China;Key Laboratory of Smart Energy&Information Technology of Tianjin Municipality,Tianjin 300072,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]天津市智慧能源与信息技术重点实验室,天津市300072

出　　处：《电力系统自动化》2023年第3期153-160,共8页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2020YFB1506800);中国博士后科学基金面上项目(2021M692378)。

摘　　要：针对负载变流器经线路聚合至共母线直流系统后,其线路电感与负载变流器输入滤波电容构成的LC振荡环节落入负载变流器控制带宽内,从而导致整个共母线直流系统发生非预期失稳的现象,提出了负载子系统自稳性判据。首先,建立了负载侧计及线路影响的恒功率负载模型,研究了负载变流器控制带宽对共母线直流系统稳定性的影响。然后,确定了负载变流器的控制带宽选取范围,使得计及线路影响的恒功率负载阻抗在LC振荡频率处的阻尼为正,进而确保整个共母线直流系统稳定。最后,硬件在环仿真的实验结果验证了负载变流器控制带宽对系统稳定性影响理论分析的有效性。When the load converter is aggregated to the DC system with common bus through the line, the LC oscillation link composed of the line inductor and the input filter capacitance of the load converter falls into the control bandwidth of the load converter, which leads to the unexpected instability of the whole DC system with a common bus. Therefore, the load subsystem stability criterion is proposed. First, the constant power load(CPL) model considering the influence of the line is established and the influence of load converter control bandwidth on the stability of the DC system with a common bus is studied. Secondly, the control bandwidth selection range of the load converter is determined so that the damping of the CPL impedance considering the influence of the line is positive at the LC oscillation frequency, and the stability of the whole DC system with a common bus is ensured. Finally, the experimental results of the hardware-in-the-loop simulation verify the effectiveness of the theoretical analysis of the influence of the load converter control bandwidth on the system stability.

关 键 词：负载变流器 共母线直流系统 恒功率负载 控制带宽 振荡频率 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM712