HVDC Overhead Line Insulators Selection and Design Update Features

摘要

The increasing number of HVDC projects has raised new interest in the design of components used in various materials dedicated to DC applications. For example, the unidirectional electric field in a dielectric subjected to a DC voltage generates specific stress conditions resulting in unique features making up the design of insulators. Likewise, the impact of polarization in the environment near a DC line requires special attention for airborne contamination which modifies the ability of a string of insulators to withstand the operating voltage under any circumstances. This paper will review the main features of DC overhead line insulators with specific details related to the various technologies available. Contamination aspects will also be discussed including the latest developments in IEC 60815 [1] as well as new mitigation methods for severe contamination conditions.