在小水电站中,为节省投资,10kV和35kV线路一般采用简单的过电流保护,第1段电流作为主保护,瞬时动作跳闸,第2段电流为后备保护,延时动作跳闸。然而,由于小水电站装机一般为2～3台,电站与系统容量小,加之负荷的季节性,运行方式变化大,在继电保护整定计算时,规程要求按最大运行方式整定而按最小运行方式校验。这样最大和最小运行方式悬殊太大,使得采用 In small hydropower stations, in order to save investment, 10kV and 35kV lines generally adopt simple overcurrent protection. The current in the first stage is used as the main protection, the instantaneous action is tripped, the second stage current is the backup protection, and the delayed action is tripped. However, due to the installation of small hydropower stations is generally 2 to 3 units, power plants and system capacity is small, coupled with the seasonal load, changes in operating mode, the relay protection setting calculation, the rules require maximum operating mode set by the minimum operating mode check. This is the largest and smallest operating disparity is too large, making use of