Transient stability assessment of AC/DC hybrid power system with VSC-MTDC

摘要

Flexible DC transmission (VSC-HVDC) after a large number of access to the power system, the flexible control and unique topological structure will greatly change the system fault response characteristics. This paper aims at studying the effect of VSC-MTDC system of different topological structures and different control modes on power system transient stability. In this paper, firstly, a four terminal flexible HVDC transmission system is constructed. The statistical analysis of clearing time critical with different topologies in three phase short circuit fault is carried out. Through statistical analysis, the relationship between VSC-MTDC topology and transient stability is obtained. Based on that, studying the influence of control mode on transient stability, in turn, four converters are set to the constant DC voltage control, analysis of the impact of control on the stability of the power grid integrated proximal and distal line fault. Finally combined with extended equal area criterion (EEAC) analyze qualitatively the influence of VSC-MTDC accessing on the transient stability of power system.