Insulation status assessment of cast‐resin current transformers based on digital partial discharge measurement

Abstract Three cast‐resin current transformers with different PD inception voltages of 43kV, 24kV and 12kV, respectively, are used in accelerated aging tests during which PD information is detected and measured. Lastly, the real measurement results of two cast‐resin current transformers are used to examine the feasibility of the proposed determination rules. Our study shows that the slop of the average discharge amount's development trend is more suitable for insulation status determination than other parameters, and said slop's accuracy and practicality is valuable for continuous research in insulation aging.