On the Likelihood of Partial Discharge Inception in Laminated Busbars from Electrified Ships

The likelihood of PD inception in Laminated Bus Bars (LBB) in the presence of defects embedded in the insulating material is investigated in this paper. The rationale behind is to understand if there is any potentiality of PD inception in defects internal to resin, considering the design electric fields, but also potential defects that can be present in MV electrical insulation systems that contain triple points and dry-resin molding. For this purpose, simulations of electric field distribution and models for PD inception are put together for an exploratory work that can drive experimental investigations and quality or commissioning testing procedures. Defects considered in this paper range from conductive protrusions to cavities or microcracks, possibly formed during the manufacturing process, or on field, by to thermo-mechanical aging. It is shown that voltage levels of few kV are already sufficient to incept PD in insulation defects, even of small size.