基于组合趋近律的VSC-HVDC滑模电流控制设计和稳定性分析  

Sliding Mode Current Control Design and Stability Analysis of VSC-HVDC Based on Combinatorial Reaching Law

作　　者：赵书强[1] 邵冰冰 高本锋[1] 李忍[1] 裴继坤 ZHAO Shuqiang;SHAO Bingbing;GAO Benfeng;LI Ren;PEI Jikun(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学新能源电力系统国家重点实验室

出　　处：《高电压技术》2019年第11期3603-3611,共9页High Voltage Engineering

基　　金：河北省自然科学基金(E2017502075);中央高校基本科研业务费专项资金资助(2018QN079)~~

摘　　要：针对柔性直流(VSC-HVDC)输电系统的稳定性问题,分析了矢量控制对VSC-HVDC系统稳定性的影响。针对存在的不稳定性现象,在基于趋近律的滑模电流控制(SMCC)下对VSC-HVDC的内环矢量电流控制进行了设计。同时针对基于指数趋近律的SMCC存在稳态抖振较大的不足,提出了一种适用于VSC-HVDC的基于组合趋近律的SMCC策略,分析了该策略对系统小干扰稳定性的影响。最后,在PSCAD/EMTDC中搭建了VSC-HVDC的仿真模型,对设计的基于组合趋近律的SMCC策略进行仿真验证。结果表明:设计的基于组合趋近律的SMCC相比于基于指数趋近律的SMCC减小了稳态时的抖振,同时SMCC对系统小干扰稳定性的影响可等效为一个内环比例系数随时间变化的比例环节,可消除传统矢量控制内环积分系数较小引起系统不稳定振荡的现象。In view of the stability problem of voltage-source-converter-based high-voltage direct-current(VSC-HVDC)transmission system,the influence of vector control on the stability of the VSC-HVDC system was analyzed.The inner loop vector current control of VSC-HVDC was designed under sliding mode current control(SMCC)based on reaching law to improve the stability of VSC-HVDC.At the same time,in accordance with the disadvantages of SMCC based on exponential reaching law with large steady-state buffeting,a new SMCC strategy based on combinatorial reaching law was proposed,the influence of the strategy on the small-signal stability of the system was analyzed.Finally,a VSC-HVDC model was built in PSCAD/EMTDC,the proposed SMCC based on combinatorial reaching law was verified.The results show that,compared to SMCC based on exponential reaching law,SMCC based on combinatorial reaching law can be adopted to decrease the steady-state buffeting,and the influence of SMCC on the small-signal stability of the system can be equivalent to a time-varying proportional component of the inner loop,which can eliminate the unstable oscillation phenomenon of the system due to the small inner loop integral parameters.

关 键 词：柔性直流输电系统 稳定性 组合趋近律 矢量控制 滑模电流控制 

分 类 号：TM721.1[电气工程—电力系统及自动化]