背靠背柔性直流接入电网后的影响评估

摘要

考虑到目前对大容量背靠背柔性直流接入电网的影响评估尚缺少具有全面性且通用性的方法, 提出一种适用于分析背靠背柔性直流接入对电网影响的评估方法.该方法主要包含静态安全性、短路电流水平、小干扰稳定性和暂态稳定性分析, 重点关注柔性直流与交流系统相互影响.以渝鄂背靠背柔性直流工程为案例, 采用电力系统分析综合程序 (PSASP)对背靠背柔性直流接入湖北电网前后的运行特性进行评估.根据评估结果, 结合电网规划与运行要求, 提出相应的电网补强工程与安控措施.仿真研究表明, 所提评估方法能有效指导电网规划与调度控制, 保证电力系统安全稳定运行.%Considering that there is a lack of a comprehensive and universal method for assessing the influence of provincial power grid with large-capacity back-to-back VSC-HVDC connection, an influence assessment method is proposed in this paper. Several aspects such as analysis of static security, short circuit current level, small signal stability and transient stability are included in the method. Interaction between VSC-HVDC and AC system is emphatically considered. Taking back to back VSC-HVDC connecting Chongqing and Hubei power grid as an example, the operation characteristics of Hubei power grid are assessed with Power System Analysis Software Package (PSASP). According to assessment results, the corresponding reinforcing project and security control measures are proposed with the consideration of power grid planning and operation requirements. The analysis shows that the influence assessment method proposed in this paper can effectively guide the planning and dispatch control of power grid and ensure the safe and stable operation of the power system.