柔性直流输电控制与交流系统次同步交互机理研究  

The Mechanism of Sub-synchronous Interactions Between Converter Control of VSC HVDC and Power Systems

作　　者：付强[1] 杜文娟[1] 王海风[1] FU Qiang;DU Wenjuan;WANG Haifeng(State Key Laboratory of Alternate Electric Power Systems with New Energy Resources（North China Electric Power University)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学)

出　　处：《中国电机工程学报》2018年第13期3717-3726,共10页Proceedings of the CSEE

基　　金：国家重点研发计划项目(2016YFB0900602)~~

摘　　要：该文针对柔性直流输电控制系统引起的次同步交互进行了研究,建立了直流换流站控制系统作为反馈环节的混联系统线性化模型,分析了与交流系统之间的次同步动态交互过程,揭示了对交流系统次同步振荡的影响机理,提出了适用于分析多机电力系统次同步稳定性的开环模式理论,得出当直流换流站控制子系统的开环模式与交流子系统的开环模式接近时,交直流闭环系统间将可能产生较强的次同步动态交互而引起交直流混联系统的次同步振荡。进一步地,基于开环模式理论给出了次同步振荡稳定性的判据,不仅能够简单准确地评估闭环系统的稳定裕量,还能够预测闭环混联系统的次同步振荡模式,为评估柔性直流输电控制系统对次同步振荡的影响提供了有效的方法。最后,以3机9节点电力系统为例,采用模式分析法和时域仿真法验证了上述结论的正确性。Sub-synchronous control interactions caused by the converter control system of VSC-based HVDC in power systems was studied, and the linearization model of AC/DC hybrid power system, which takes the VSC station as the feedback control loop, was established in this paper. The presented open-loop model theory indicates that the strong sub-synchronization dynamic interaction will happen if the open-loop model of VSC control loop is closed to the open-loop model of AC system. Further, the stability criterion based on the open loop mode theory was proposed, not only can assess the stability margin of the closed-loop system more accurately, but also can predict the model of closed-loop system, it provides an effective computational method for stability evaluation of AC/DC hybrid power system. Finally, the stability criterion was verified by using the modal analysis method and time domain simulation method on the basis of the 3 machines and 9 nodes power system.

关 键 词：柔性直流输电 次同步交互 开环模式理论 次同步振荡稳定性机理 

分 类 号：TM712[电气工程—电力系统及自动化]