以2010年夏季大方式下的南方电网为对象，详细研究了其受端广东电网内部严重故障和直流输电线路故障对南方互联电网其他直流输电系统的影响，以及对整个南方电网系统的影响。首先用机电暂态仿真软件PSD-BPA进行仿真计算，筛选出对系统有严重危害的故障；然后对原始广东电网进行等值，建立包含详细直流模型的适当规模的网络结构；最后用PSCAD/EMTDC电磁暂态仿真软件对等值网络进行仿真模拟。研究结果表明，广东电网结构坚强，能够满足安全稳定导则中一级、二级安全稳定标准要求。

Taking the summer operation mode of South China Power Grid (SCPG) in 2010 as research object, the affects of serious faults happened in UHVAC transmission lines as well as faults happened in HVDC transmission line within Guangdong Provincial Power Grid (GPPG), that is the receiving end of SCPG, on other HVDC power transmission systems in South China Interconnected Power Grid are researched in detail. Firstly, the simulation is conducted by electromechanical transient simulation software PSD-BPA and the faults that badly endangers power grid security are screened out; then the dynamic equivalence of original GPPG is carried out to built an appropriate-scale network structure containing detailed HVDC model; finally, by use of electromagnetic transient simulation software PSCAD/EMTDC the obtained equivalent power grid is simulated. Simulation results show that the stability margin of GPPG can meet the first-grade and the second-grade demands of security and stability specified in Guide on Security and Stability for Power System.