含风电的VSC-HVDC并网系统暂态特性分析

Analysis on Transient Characteristics of VSC-HVDC Grid-connected System with Wind Power

为了提高柔性直流输电(VSC-HVDC)并网系统的暂态稳定运行特性,文中基于送端采用双馈风电机组(DFIG),建立VSC-HVDC输电并网系统,研究该系统的并网暂态运行特性。为解决电网故障时并网VSCHVDC直流电压失稳问题,提出并网VSC-HVDC直流电压与VSC间协调控制策略。在MATLAB/Simulink平台搭建风电并网仿真模型,仿真分析风速变化、并网点故障等情况下系统的暂态特性以及并网点故障时是否采用新控制策略进行实验仿真对比,研究结果表明:风速变化以及并网点故障时并网系统能够快速恢复稳定性且采用的协调控制策略有效的抑制直流电压的突增,从而增强了系统的暂态稳定特性。

In order to improve the transient stability characteristics of the flexible HVDC(VSC-HVDC)connectedgrid system,in this paper,based on the adoption of doubly-fed induction generator(DFIG),a flexible HVDC(VSC-HVDC)grid-connected system is established to study transient operational performances.In order to solve the problem of VSC-HVDC voltage instability of grid-connected VSC-HVDC in Fault,the coordinated control strategy between VSC-HVDC DC voltage and VSC is proposed.The wind power grid-connected simulation model is established based on MATLAB/Simulink platform,the transient stability characteristics of the system under the case of the wind speed changes and power network fault are simulated and analyzed,and whether or not to adopt new control strategy for experimental simulation comparison.The results show that when the wind speed changes and the grid fault,the grid-connected system can recover quickly and the coordinated control strategy can effectively suppress the sudden increase of DC voltage,thus enhancing the transient stability of the system.