同杆双回线准三相运行与跳合闸策略

Quasi-three-phase Operation and Tripping and Reclosing Strategy of Double-circuit Transmission Lines on the Same Tower

首先利用六序分量法对同杆双回线解耦,结合边界条件推导提出一种适用于各种非全相运行的正同序附加阻抗计算方法,以实际工程参数计算了准三相运行下的极限传输功率、输电线过载率和电压电流不平衡度等,验证了准三相运行的优势与可行性。然后根据故障同名相数对同杆双回线短路故障进行分类优化,在满足准三相运行前提下以尽可能减少切除相和减少线路重合需求为原则,形成改进跳合闸策略。将所提改进跳合闸策略与传统跳合闸策略分析对比,结果表明改进策略在维持系统两端电气联系和避免重合于永久性故障方面具有明显优势,可为准三相运行提供机制。

A method is recommended for calculating the additional positive sequence impedance in the same direction suitable for all kinds of fault with the use of the six-sequence component.With the proposed method an analysis is made on the feasibility and potential economic benefits of quasi-three-phase (QTP) operation. An example is studied with actual engineering parameters to verify the advantages of QTP operation.Then the specific decision-making process of improved tripping and reclosing strategy is elaborated.The strategy makes classified optimization according to the number of namesake fault phases, minimizing removal and reducing reclosing requirements on the premise of satisfying QTP operation.Analysis and comparison with the traditional tripping and reclosing strategy is made with the above engineering parameters.It is proved that the proposed strategy is able to provide favorable conditions for the application of QTP operation.