A review on polymeric insulation for high-voltage application under various stress conditions

Polymeric material draws a great attraction in the development of insulation for High Votage Direct Current (HVDC) applications. Insulation material is the deciding key factor to increase the operating voltage and to transmit the bulk power with minimized power loss. Premature breakdown, high withstanding temperature, and impacts of space charge accumulation are all issues faced by the insulation material. Material qualities such as dielectric, electrical, structural, and mechanical properties are directly affected by the issues. Therefore, this paper provides an overview of the dielectric properties of polymeric materials and their composites under various stress conditions. The stress includes AC, DC, superimpose and combined (AC and DC) stress under which the dielectric constant, dielectric losses, electrical strength, and space charge distribution of polymeric insulating materials such as low-density polyethylene, high-density polyethylene, cross-linked polyethylene, polypropylene, and random copolymer (RCP), as well as their composites, are explored. Polypropylene and RCP outperform all other polymers in terms of breakdown strength and space charge suppression under various stress conditions. RCP is a developing material that also has the potential to be an effective thermoplastic insulation material in the future.