The AM Series Middle Voltage Protection Relay adopts mature and reliable protection principles and algorithms, strong anti-interference performance, high reliability, flexible protection implementation, and redundant design for communication. The AM protection relay has an independent high-precision current measurement circuit, multi-channel switch value acquisition and relay output, and can be used in conjunction with the integrated automation system of the substation or the electrical automation system of the power plant, and can realize the unattended end-user substation distribution automation system. The protection relay can be installed centrally in a group of screens, or directly installed on the switch cabinet for decentralized control.