考虑架空线路动态热定值和 N‒1 安全准则的源-网-储系统分布鲁棒优化运行方法

Due to the randomness of renewable energy, power flow becomes complex and variable. In addition, a large amount of renewable energy has to be remotely transferred and consumed. Therefore, transmission congestion becomes increasingly serious. Dynamic line rating (DTR) technology can improve the transmission capacity of existing overhead lines and fully utilize the flexibility of power system. Especially under N‒1 contingency, applying DTR technology can alleviate severe transmission congestion. However, it is still challenging to optimize DTR with security assurance, which suffers from dimension curse in traditional approaches under N‒1 contingency. In this paper, a two-stage distributionally robust optimization (DRO) approach is proposed to improve the transmission capacity of overhead lines. A transient temperature calculation model of overhead lines is firstly proposed and simplified to preserve the convexity property in the following DRO model. Then, a two-stage DRO model for source-grid-storage system considering DTR of overhead lines and N‒1 security criterion is established to avoid the blackout under N‒1 contingency. A linearized alternative current power flow model considering reactive power and network losses is utilized to calculate the line current more accurately. Finally, case studies on IEEE-24 bus system and IEEE-118 bus system verify the effectiveness of the proposed method.