A paper on the development of 550 kV dry air insulated current transformers

The first stage determines the dry-air insulation system and strictly controls impurities and particle content; the second stage conducts multi-electrode tests under UHV operating conditions, clarifies the sensitivity to electric field non-uniformity, and establishes insulation evaluation and design criteria for 550 kV current transformers; the third stage optimizes the electric field distribution by adding an intermediate electrode and matches appropriate gas pressure parameters to realize non-destructive replacement of equipment; the fourth stage analyzes the characteristics of discharge characteristic gases and constructs operation monitoring, fault warning and operation & maintenance standards.

This research systematically solves the problems of insulation performance, structural feasibility and long-term reliability of dry-air insulated UHV equipment, providing a complete technical system and guarantee for engineering applications, and promoting the development of environmentally friendly and efficient power transmission technologies.