本文所介绍的微机短线路纵差保护方法，适用于３５ｋＶ 及以下的短距离输电线路。方案所配备的纵联差动保护采用分相差动保护原理，以相电流差突变量作为起动元件，差动元件采用全周付氏算法，计算出电流量的实部和虚部，再对两侧的电流相量进行比较，以确定是否在区内，在方向元件的选取上，首选正序故障分量。信号传输可采用光纤、屏蔽电缆或直流单高压开关量引导线。本文主要介绍了采用光纤的纵差保护的原理、构成和动模试验结果。 This article describes the computer short circuit differential protection method is suitable for short-distance transmission lines 35kV and below. Program with the longitudinal differential protection using the principle of split-phase differential protection, the phase current difference mutation as a starting component, the differential element using the full week Fu’s algorithm to calculate the real and imaginary part of the current, and then the two Side current phasors compared to determine whether the region, the direction of the component selection, the preferred positive sequence fault components. Signal transmission can be fiber, shielded cable or DC single high voltage switch lead. This paper mainly introduces the principle of differential protection using optical fiber, composition and dynamic mode test results.