摘要
针对交—直互联系统的次同步振荡问题,利用复转矩系数法研究含串联电容线路的风电场经VSC-HVDC系统并网的次同步振荡机理。首先,利用小信号模型推导了转速变化对发电机电磁转矩的变化量;然后基于直流输电的控制参数、控制策略、直流线路长度等方面来研究系统次同步振荡影响因素,利用测试信号法得到系统阻尼特性;最后,利用PSCAD/EMTDC仿真软件进行时域仿真验证。研究表明,比例系数越大,时间常数越小,系统越容易发生次同步振荡;在抵御系统次同步振荡能力方面,直流输电送端采用定交流电压控制方式要强于定无功功率控制方式;直流线路越长,为系统提供正阻尼越大,直流电压波动越小。
To deal with the sub-synchronous oscillation in the AC-DC interconnecting system,the complex torque coefficient analysis based on the damping characteristic is utilized to investigate the mechanism of the Sub-synchronous Oscillation in this paper.Firstly,a small signal model is built to derive the relationship between the variation of angular speed and the electromagnetic torque.Then,the impacts of the PI control parameters,VSC control strategy and DC line length on the oscillations are investigated,and the testing signal methodology is utilized to obtain the system damping characteristics.Finally,the analytical results are verified by the simulations performed in PSCAD/EMTDC.It can be concluded that SSOs are much easier to be triggered when the high proportional coefficient and low time constant are employed.The AC voltage control strategy at the sending end of VSC has the better SSO damping performance than the reactive power control strategy.Moreover,the damping performance could be improved by long DC transmission lines,which mitigates the DC voltage fluctuation in the HVDC system.
作者
苏勋文
裴禹铭
崔含晴
张冬妮
徐宪忠
SU Xunwen;PEI Yuming;CUI Hanqing;ZHANG Dongni;XU Xianzhong(Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology,Ministry of Education,Northeast Electric Power University,Jilin 132012,China;School of Electrical and Control Engineering,Heilongjiang University of Science and Technology,Harbin 150022,China)
出处
《电力科学与技术学报》
CAS
北大核心
2021年第1期160-168,共9页
Journal of Electric Power Science And Technology
基金
国家自然科学基金(51677057)
博士后研究人员落户黑龙江科研启动项目(LBH-Q15125)
现代电力系统仿真控制与绿色电能新技术教育部重点实验室项目(MPSS2019-05)。
