青藏直流联网工程负荷特性对短路电流计算影响的分析

Researches on the Load Representation of Qinghai-Tibet Power Grid AC/DC System

随着格尔木—拉萨直流输电工程的开工建设,该工程项目的实施对于促进全国联网,推动直流输电装备技术进步,促进西北地区能源资源在更大范围内优化配置,推动西藏乃至西北社会经济又好又快发展意义十分重大。在西藏电网与青海电网的联网,是我国乃至世界上海拔最高的直流输电工程项目,作为项目的最基础性研究,确定换流站接入处交流系统的强度无疑是至关重要的。基于综合潮流程序PSASP及电磁暂态仿真软件PSCAD/EMTDC进行了相关问题的仿真研究,针对不同负荷特性对确定系统短路比的影响做出分析研究,为更加真实反应青海电网强度提供可靠的技术支撑。

With the Geermu-Lhasa HVDC project（of the highest altitude among HVDC projects in the world） commenced,Tibet power grid will be interconnected with Qinghai Power grid in near future.Implementation of this project is of substantial significance in promoting the national interconnection of power grids,upgrading the DC transmission equipment manufacture,improving the optimized configuration of the energy resources in a larger ranger in the northwest,and reinforcing the rapid and sound economical development in Tibet and the northwest as well.As one of the fundamental research projects,it is vital to determine the strength of the AC system at the intake point of the converter station.This paper,by means of the Power System Analysis Software Package（PSASP） and electromagnetic transient simulation software PSCAD/EMTDC,conducted simulation studies on the related issues,and analyzed the impacts on determining the short-circuit ratio of the system under different load characteristics so as to provide technical support in determining the strength of Qinghai power grid with a higher reliability.