Influence of high-permittivity barriers on PD activity in three-layer dielectrics

It is a well-known fact that the breakdown voltage of dielectrics in a divergent field may be increased by using an additional insulating layer (a barrier) placed at the optimal position between the electrodes. This paper is devoted to the investigation of the barrier effect in solid dielectrics in a quasi-uniform electric field, i.e. the study of the relationship between partial discharge (PD) activity and the barrier position in the insulating gap. It is established that the PD parameters depend on the barrier position in the gap. In particular, the ignition voltage of critical PDs is increased by more than 50% at the optimal barrier position compared to that for other barrier positions.