In several DC bushing failures in recent years

metal particles have been found inside the bushing

and the diameter was between several microns and several tens of microns. The adhesion and movement of metal particles inside the bushing had impact on the electric field distribution and safely operating. In order to calculate the initial motion field strength of particle

the position and shape of metal particles inside the fault bushing were analyzed

and the motion model of free metal particles with different sizes and forms were established. A test platform was built.The particle motion characteristics were analyzed according to the operating bushing

and the particle motion model was verified. The results showed that free metal particles in the DC bushing would move under the influence of the electric field. The initial motion field strength was related to factors such as particle diameter

width

and thickness.The research result could be used as structural optimization and design of DC bushings

which was worth a further study both in academic and engineering application.