山西阳城电厂送出工程是典型的大容量电厂经长线路送电的系统 ,需安装切机控制装置 ,以确保系统稳定性。文中对采取多段电压补偿元件不借助于通道进行故障判别切机的方案进行分析计算。结果表明多段电压补偿元件原理简单 ,动作速度快 ,但选择性不好 ,整定计算复杂 ,用于阳城送出工程应在保护范围和切机台数上加以限制 Shanxi Yangcheng Power Plant project is a typical high-capacity power plant by long lines of power transmission system, the need to install cutting machine control device to ensure system stability. In this paper, multi-section voltage compensation components without the help of the channel fault diagnosis cut the program analysis and calculation. The results show that the multi-stage voltage compensation element is simple in principle and fast in operation, but its selectivity is not good and the setting calculation is complicated. The project for sending out the Yangcheng should be limited in the scope of protection and the number of machines to be cut