南方电网交直流系统的简化方法

为了在PSCAD/EMTDC中搭建南方电网交直流系统,研究南方电网交直流动态特性,提出了简化南方电网大规模交直流系统的方法。该方法保留交直流系统中500 kV电压等级的主干网架、直流线路以及直流换流站与主干网架的交流通道,而对交流系统220 kV及以下电压等级的低压网络进行简化等值。具体包括以下步骤:首先对主干网架上的500 kV母线进行无误差的简化;然后对系统中所有500 kV母线进行扫描,确定每个500 kV母线所连的低压网络;最后对每个500 kV母线下的低电压等级网络进行简化,对等值发电机和负荷的动态参数进行聚合。使用文中所述方法对南方电网交直流系统进行简化。动态仿真结果及误差分析验证了该方法的有效性。

A Reduction Method for AC/DC System of China Southern Power Grid

To construct simulation model for AC/DC system of China Southern Power Grid(CSG) by PSCAD/EMTDC software to research dynamic characteristics of the AC/DC system,a method to reduce large-scale AC/DC system of CSG is proposed.In the proposed method,the 500 kV backbone network of the AC/DC system,DC transmission line and the AC transmission lines connecting DC converter stations to AC backbone are reserved,and the simplification and equivalence of low voltage AC networks,namely in 220 kV and lower voltage classes,are performed.The concrete procedures are as following: firstly,the 500 kV buses of backbone network are simplified by zero difference technique;then all 500 kV buses of backbone network are scanned to find out to determine the lower voltage network connected to each 500 kV bus;finally the lower voltage network connected to each 500 kV bus are reduced,and dynamic parameters of equivalent generators and loads are aggregated.Using above-mentioned method the CSG is reduced and both dynamic simulation results and error analysis results show that the proposed method is effective.