考虑传输安全裕度的电力系统发电经济调度

Transmission Safety Margin Constrained Unit Commitment in Power Systems

对于考虑不确定性风电等新能源接入的电力系统调度,合理的潮流分布对降低线路过载风险、提高经济调度的鲁棒性具有重要意义。为此,提出传输安全裕度和备用可用性的概念,并建立考虑传输安全裕度的经济调度模型,通过引入合理的成本约束,保证运行成本与传统调度时相比不会显著增加。从传输安全裕度、备用可用性、安全裕度与运行成本的关系3个方面进行数值测试,验证方法的有效性。结果表明,该方法可提高传统调度中阻塞或重载线路的安全裕度,有效避免因线路传输容量限制而导致的备用不足问题,从而提高调度计划应对不确定性扰动的能力,因此该模型可获得安全性和经济性更好的平衡。

For generation schedules considering uncertain wind power resources integrated into power grids, obtaining reasonable power flow is very important to lower the overload risks of transmission lines and increase the system security and robustness. The concepts of transmission safety margin and reserve availability were proposed in this paper, and then a transmission safety margin constrained unit commitment formulation was established. Reasonable cost constraint was added to guarantee that there could be little increase in the operation cost compared with conventional unit commitment. Numerical tests were conducted in terms of transmission safety margin, reserve availability under uncertain wind power output and variation tendency of transmission security margin with generation costs to verify the effectiveness of the method. It turns out that this method can increase the safety margin of congesting or heavy-loaded lines compared with conventional unit commitment model, the reserve availability problem caused by transmission capacity limits can also be effectively avoided and the robustness of the scheduling planes against uncertainty is improved. Thus, a compromise between secure and economic operation can be achieved.