单选题 当电气设备出现异常运行状态时,电力系统继电保护自动、()、有选择地(),让值班人员进行处理,或切除继续运行会引起故障的设备. [Single-choice question] When electrical equipment is in abnormal operation state, the relay protection of power system will automatically, ( ) and selectively ( ), so that the personnel on duty can handle it or cut off the equipment that may cause faults if it continues to operate