内蒙古—京津冀直流工程投运后系统稳定特性影响分析

Analysis on Influence of System Stability Characteristics After Operation of Inner Mongolia to Beijing-Tianjin-Hebei District DC Project

内蒙古电网首个网对网直流工程内蒙古—京津冀2回±660kV直流及其配套工程投运后,对内蒙古电网特性产生影响,从短路电流、短路比、暂态稳定特性等方面进行了仿真分析,仿真结果表明,该直流工程接入后,电网短路电流水平整体上升,直流送端电网为强交流系统,直流短路比较高,有利于内蒙古电网大规模新能源外送,但在网汇方式发生直流双极闭锁后,存在电压稳定问题,需合理切除配套电源,进一步加强网架结构建设。

This paper analyzes the influence of first grid⁃to⁃grid DC project of West Inner Mongolia Power Grid,namely the two±660 kV DC projects from Inner Mongolia to Beijing-Tianjin-Hebei District on the characteristics of Inner Mongolia power grid,and the simulation analysis is carried out from the aspects of short⁃circuit current,short⁃circuit ratio and transient stability characteristics.The simulation results show that after the DC project accesses to grid,the short circuit current level of the power grid increases overall,and the DC short circuit is relatively high.The power grid of the DC transmission terminal is a strong AC system,which is conducive to the large⁃scale new energy transmission.The DC bipolar blocking occurs in the mode of network collection,which exists the problem of voltage stability.Therefore,it is necessary to cut off the supporting power supply reasonably and strengthen the construction of network structure.