Fault current decay time constant calculation method based on particle swarm

The invention discloses a fault current attenuation time constant calculation method based on a particle swarm. The fault current attenuation time constant calculation method comprises the following steps of 1, defining a current attenuation curve function; step 2, selecting a curve of a to-be-fitted part in the actual fault recording waveform; 3, defining a target function; 4, defining a particle swarm and the position and the moving speed of each particle in the particle swarm, initializing the position and the moving speed of each particle, and initializing the historical optimal positions of the particle individuals and the swarm; 5, updating the moving speed and the moving position of each particle, and calculating the adaptive value of the self-defined target function of each particle and the relative error of each particle at a plurality of fault moments; and step 6, according to the relative error of each particle at a plurality of fault moments, updating the historical optimal positions of the partic