At a 220kV substation in the main grid,both the load shedding implementation station and the 220kV automatic switchover devices are installed,which results in complex secondary circuits in the substation while increasing the maintenance workload.To remedy such a situation,a novel automatic safety control device integrating the function of load shedding implementation station and automatic switchover devices is developed with the characteristics of the two kinds of devices taken into account.The configuration scheme of the novel device and the standardized and modularized framework of the system are studied,and the coordination between the functions of the two kinds of devices is analyzed at length.The designed novel automatic safety control device is successfully applied at a 220kV substation in Guangdong power grid.