中文摘要：

采用非线性动态方法中的Hopf分岔概念及分析方法对单馈入HVDC系统的动态稳定性进行了全面的分析。研究了HVDC系统在不同控制模式下产生的Hopf分岔现象，分析了HVDC系统在Hopf分岔点附近的稳定性，并讨论了HVDC系统的控制参数对系统稳定性的影响。分析表明，HVDC系统有可能在有功率达到最大值之前已失稳，控制系统的增益对系统稳定性影响较大。

英文摘要：

The dynamic stability of single-infeed HVDC systems was analyzed comprehensively by nonlinear dynamic method. Hopf bifurcation caused by HVDC systems was explored. The stability of HVDC systems near a Hopf bifurcation point was analyzed, and the effect of the control parameters on the HVDC system stability was discussed in detail. The analysis shows that the HVDC system may have lost stability before its active power reaches the maximum value. Furthermore, the effect of the proportional factor on HVDC system stahihty is significant.