The supervisory control and protection system of electric power generation and substation unit is made up of relay protection products, the controlling are completed by PLC, and the communication monitor interface of host computer is developed by domestic software. 采用继电保护产品组成电力发变机组保护系统,并辅以PLC完成控制功能,应用国产软件开发上位机的通讯监控界面。