考虑水电富集地区线路利用率的阻塞场景筛选及电网扩展规划

在水电富集地区，输电网中的水电比例较高，受水电丰枯特性影响，部分输电线路利用率季节差异巨大，因此，研究输电线路利用率同系统经济性协调的扩展规划模型和方法具有重要意义。基于此，本文提出一种考虑线路利用率的含高比例水电输电网扩展方法，考虑水电丰枯特性的影响，以输电线路的利用率引导输电网扩展规划决策。首先，考虑输电线路的安全裕度与发展裕度提出输电线路利用率指标。其次，以最小化输电网的发电成本、失负荷惩罚成本与弃水惩罚成本为目标函数，建立含高比例水电的输电网最优经济调度模型，并在此基础上提出输电线路的阻塞利用率和输电网的阻塞率计算方法。而后，通过分别计算丰水期负荷大方式、丰水期负荷小方式、枯水期负荷大方式以及枯水期负荷小方式四种运行场景下输电线路的阻塞利用率和输电网的阻塞率，对严重阻塞场景进行筛选。最后，以输电网线路建设成本、输电网运行成本、失负荷惩罚成本以及弃水惩罚成本最小为目标函数，提出考虑阻塞场景的含高比例水电输电网扩展规划模型，将严重阻塞场景纳入含高比例水电的输电网扩展模型中，形成输电网线路投资决策。算例仿真结果验证了所提考虑线路利用率的含高比例水电输电网扩展规划方法的有效性。

Congestion Scenarios Screening and Expansion Planning of Transmission Network with High Proportion of Hydropower Considering Capacity Utilization of Transmission Lines

In the transmission network with high proportion of hydropower, the capacity utilization of transmission lines varies seasonally due to the impact of hydropower abundance and depletion characteristics. In this paper, an expansion planning method of transmission network with high proportion of hydropower is proposed by taking into account the capacity utilization of transmission lines. The capacity utilization of transmission lines is used to guide the transmission network expansion planning decision considering the impact of hydropower abundance and depletion characteristics. First of all, the indices of capacity utilization of transmission lines and congestion rate of transmission network are proposed considering the safety margin and development margin, and the severe congestion scenarios are identified by calculating the capacity utilization of transmission lines and congestion rate of transmission network under different operation scenarios, respectively. With the objective of minimizing the cost of investing in transmission lines, the operation cost of transmission network, the penalty cost of load shedding and the penalty cost of hydropower spillage, the transmission network expansion planning model with high proportion of hydropower is constructed. Specially, the severe congestion scenarios are incorporated into the transmission network expansion planning model to derive the investment decision of transmission lines. The numerical results verify the effectiveness of the proposed transmission network expansion planning method with high proportion of hydropower considering the capacity utilization of transmission lines.