摘要
常规内模控制下的柔性直流输电(VSC-HVDC)系统存在有功、无功功率解耦效果不理想,动态性能有待提高等问题,文章在原有内模控制基础上添加前馈控制器,构成一种二自由度内模对系统进行解耦控制。针对VSC-HVDC交流系统5、7、11、13次谐波含量比较高,本文采用二自由度内模控制与改进重复控制相结合的控制方式对系统谐波进行补偿和抑制。为验证该方法的正确性和有效性,在PSCAD/EMTDC中的一个两端VSCHVDC系统模型进行仿真分析,结果表明该控制策略可以改善系统的跟随性能,实现对有功和无功功率较好的解耦,较大程度地抑制低次谐波,提高VSC-HVDC系统的电能质量。
The VSC-HVDC system under the control of the normal internal model has the problems that decoupling effect of the active and reactive power is not ideal, dynamic performance needs to be improved and so on. Thus, a kind of two-degree-freedom internal model for decoupling control of the VSC-HVDC system is made up, which is based on the normal one with a feedforward controller added in this paper. In allusion to the high harmonic content of the 5-, 7-, 11-, 13 order harmonics in the AC system of VSC-HVDC, a control strategy that two-degree-freedom inter- nal model controller combined with the modefied repetitive controller was used to compensate and suppress the har- monics in the paper. To verify the validity and availability of this control method, a VSC-HVDC system model of two terminals was simulated and researched in PSCAD/EMTDC. The results verify that the control strategy can improve the performance of tracking and achieve a better decoupling performance of the active and reactive power, also, which can suppress the low-order harmonics largely and improve the power quality of VSC-HVDC system.
出处
《电测与仪表》
北大核心
2016年第2期34-39,44,共7页
Electrical Measurement & Instrumentation
关键词
VSC-HVDC
二自由度内模
解耦
跟随性能
重复控制
谐波含量
VSC-HVDC, two-degree-freedom internal model, decoupling, tracking performance, repetitive control, harmonic content
