Registration and simulation of partial discharges in free bubbles at AC voltage

Partial discharges in free bubbles in transformer oil are investigated both experimentally and theoretically. Optical, electric and optoelectronic registration are performed to obtain a picture of partial discharge. The time duration of electrical and optoelectronic signals is practically the same, 50 ns. Much longer time is needed for bubble deformation and its breaking, approximately several milliseconds. Electric properties obtained in experiments are confirmed by the simulation of the electrical field, “true” and “apparent” charges of partial discharge. Hydrodynamic behavior in experiments corresponds well to the simulation with the lattice Boltzmann method.