中文摘要：

构建含高压直流输电系统的多机Heffron-Phillips模型,借助模态分析理论分析直流输电系统有、无直流功率调节环节对交直流混合系统小扰动稳定性的影响,并应用根轨迹法对直流输电系统的单输入单输出超前—滞后补偿功率调制控制器参数进行整定。最后以典型交直流混合系统为例进行仿真分析,模态分析和时域仿真结果表明,采用直流功率调制可有效改善交直流混合系统的动态稳定性;基于根轨迹设计的单输入单输出超前—滞后补偿功率调制控制器方法简单、实用、容易实现。

英文摘要：

In this paper,the HVDC modulation is proposed to improve small-signal stability of hybrid AC/DC systems.Multi-machine model,including HVDC power system,is developed to study small-signal stability.Based on this model,the modal analysis is used to investigate the feasibility of damping inter-area oscillation using HVDC modulation.The parameters for single-input single-output lead-lag compensation of HVDC modulation controller are calculated by root locus.Then,the proposed control strategy is applied to design the HVDC modulation controller.The simulation results shows that utilizing HVDC to improve small-signal stability needs HVDC modulation,applying root locus to design controller is simple and easy to implement.