This paper explores the development of relay protection technology in smart grids, analyzing its applications in intelligent algorithms, digital devices, and automated coordination. The relay protection device is the core equipment that ensures the safe and stable operation of a power grid. In these cases, extra assurance of adequate relay channel management, control, and performance is needed. Part 1 describes the digital communications architecture and. The tendencies and perspective directions of development of modern digital devices of relay protection and automation (RPA) are considered. These clean energy sources, connected through inverters and flexible transmission systems, are transforming traditional grids based on synchronous generators into more flexibl cant challenges to system stability.