基于横差模电流暂态能量的同杆双回线保护方案

Protection Scheme for Double Lines on Same Tower Based on Transient Energy of Modal Differential Transverse Current

利用同杆双回线内部故障和外部故障的特点,构成了能准确区分区内、区外故障的速动保护方案。将同杆双回线各回线故障后的电流量分解为不同频段上的暂态信息和稳态信息,得到故障后电流的暂态特征,利用暂态特征的差值构成基于横差模电流暂态能量的保护方案,利用相继动作方法可迅速切除同杆双回线内部的各种故障。保护的灵敏度不受过渡电阻、雷击、故障类型、负荷电流、系统运行方式等因素的影响。此外,由于保护的数据窗很短,电压互感器、电流互感器的传变特性对保护的性能没有影响。

By use of characteristics of internal and external faults, a new fast protection scheme for double lines on same tower, which can accurately distinguish faults within the protection zone from those outside the protection zone, is proposed. Decomposing the post-fault current of each line into transient information and steady state information in different frequency bands, the transient features of post-fault current can be obtained. By use of the differential value of transient features, a protection scheme based on transient energy of modal differential transverse current for double lines on same tower is composed. By use of cascading operation method the internal faults of the double lines on same tower can be quickly switched out. The sensitivity of the proposed protection scheme is not affected by such factors as transition resistance, lightning stroke, type of fault, load current and power system operating modes. Besides, because of the short data window the performance of the proposed protection scheme is not influenced by transferring performance of CT and PT.