Partial discharge Partial discharge In electrical engineering, partial discharge (PD) is a localized dielectric breakdown (DB) of a small portion of a solid or fluid electrical insulation (EI) system under high voltage (HV) stress, which does not bridge the space between two conductors. While a corona discharge (CD) is usually revealed by a relatively steady glow or brush discharge (BD) in air, partial discharges within solid insulation system are not visible. PD can occur in a gaseous, liquid or solid insulating medium. It often starts within gas voids, such as voids in solid epoxy insulation or bubbles in transformer oil. Protracted partial
Patera (planetary nomenclature) Patera (planetary nomenclature) Patera (plural: paterae) is an irregular crater, or a complex crater with scalloped edges on a celestial body. Paterae can have any origin (volcanic, impact or other), although majority of them were created by volcanism. The term comes from Latin language, where it refers to a shallow bowl used in antique culture. This term is used in planetary nomenclature: it is a part of the international names of such features. In such names, it is capitalized and stands after the proper given name (e.g., Pillan Patera). Besides that, it can be used as a description term and