换流阀冷却控制系统的时滞稳定性分析  

Time Delay Stability Analysis of Converter Valve Cooling Control System

作　　者：江楠 董熙 邱树明 王永平[1] JIANG Nan;DONG Xi;QIU Shu-ming;WANG Yong-ping(NR Electric Co.,Ltd.,Nanjing 210000,China)

机构地区：[1]南京南瑞继保电气有限公司,南京210000

出　　处：《自动化与仪表》2023年第4期38-42,58,共6页Automation & Instrumentation

基　　金：国家电网公司总部科技项目(5100-202249004A-1-1-ZN)。

摘　　要：换流阀冷却系统是直流输电工程的重要设备,冷却水温度控制的稳定性直接影响换流阀的安全运行。首先介绍了换流阀冷却系统的原理及温度控制策略,被控对象采用带纯滞后环节的一阶惯性环节等效。为减少额外引入的时滞影响,提出冷却系统温度控制测点位置的改进方案。针对PI控制下的一阶时滞系统稳定性问题,推导出基于奈奎斯特准则的解析法,得出系统保持鲁棒稳定的时滞常数稳定域,同时分析了系统稳定裕度和控制器参数的稳定域。仿真和实验验证了解析法分析换流阀冷却控制系统时滞稳定性的有效性。Valve cooling system is an important equipment of HVDC transmission project.the stability of cooling water temperature control directly affects the safe operation of converter valve.Firstly,the principle and temperature control strategy of the converter valve cooling system are introduced.The controlled object is equivalent to the first order inertial link with a pure delay link.In order to reduce the effect of additional time delay,an improved scheme of measuring point location for temperature control of cooling system is proposed.Then,aiming at the stability problem of the first-order time-delay system under PI controller,an analytical method based on Nyquist criterion is derived,and the stability region of the time-delay constant for the system to maintain robust stability is obtained.At the same time,the stability margin of the system and the stability margin of the controller parameters are analyzed.The simulation and experimental results show that the analytical method of Nyquist criterion is correct in analyzing the stability of time-delay system.

关 键 词：换流阀冷却系统 温度控制 时滞 稳定性 奈奎斯特准则 解析法 稳定裕度 

分 类 号：TM721.1[电气工程—电力系统及自动化]