Corona discharges caused by water droplets on the surface of polymeric insulators can affect the long-term reliability of the component by lowering the surface hydrophobicity encouraging surface discharges. It is well-known that droplet-initiated discharges behave differently under AC and DC field stress affecting the hydrophobicity of polymeric outdoor insulation materials. The presented investigations study the effect of hybrid field stress on partial discharges at singular water droplets. The behavior differs depending on the direction of the electric field as also known for uniform AC or DC fields. Tangential oriented field stress is more critical to aging phenomena due to a significantly lower pd inception level. By high speed analysis of the droplet deformation the oscillation frequency is linked to the acting electrostatic forces depending on the AC and DC component of the excitatory electric field. Thus, the mechanical oscillation model is extended for hybrid field stress.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.