Research on improvement strategies and transmission capacity analysis of key sections considering multi-DC access

Aiming at the problem of limited transmission capacity of AC section caused by uneven distribution of power flow, this paper proposes a method for the maximum transmission capacity that takes into voltage source converter-high voltage direct current (VSC-HVDC). The method considers the influence coefficient of the AC section power flow after multi-DC access. Meanwhile the method considers the influence of N-1 security constraints of AC lines and DC fault constraints on the power flow of the AC section. Through the continuous iteration of this method, the DC layout method and power arrangement can be quantified, and the maximum transmission capacity of the AC and DC sections can be obtained. Also, the improvement effect of transmission capacity of the sections after the DC power is improved is studied. Finally, the effectiveness of the proposed method is verified by taking the actual data of Jiangsu power grid as an example.