The utility model belongs to the technical field of power distribution network early warning, and particularly relates to a rapid early warning device for transient stability of a
power grid, which comprises a bracket swing arm mounted on a sensor bracket, an
assembly component slidably connected to the bracket swing arm, an adjusting component arranged on the
assembly component, an early warning module arranged in the
assembly component, a hinge rod arranged at one end of the bracket swing arm, and a
power transmission mechanism arranged at the other end of the bracket swing arm, the assembling assembly comprises a swing arm sliding block, a protruding shaft is fixedly installed on the swing arm sliding block, an assembling box is slidably connected to the outer side of the swing arm sliding block, a lifting sliding groove is formed in the assembling box, and a side clamping plate is further arranged at the top of the assembling box. According to the rapid early warning device for the transient stability of the
power grid, when a line swings in a
small amplitude, the support swing arm can swing freely through the hinge rod, the swing arm sliding block slides in the axial direction of the support swing arm, the assembly box is further adapted to the position change of line swinging through the lifting sliding groove under the limitation of the protruding shaft, and therefore mechanical damage caused by line swinging is effectively reduced.