Behavior of LN2/Paper Composite Insulating Material under AC, Standard and Non-standard Lightning Impulse Voltage

To develop a high temperature superconducting (HTS) transformer, the insulating materials used should be characterized at cryogenic environment. An attempt has been made to measure the AC, standard impulse and bi-directional oscillatory non-standard impulse breakdown strength and the corresponding partial discharge. Kraft paper and press paper used in transformer insulation were used for characterizing the dielectric behavior under both cryogenic temperature which is created using liquid nitrogen and at room temperature. The dielectric characteristic at room and at cryogenic temperature comparison has been made to quantify the superiority of the solid insulating materials at Liquid Nitrogen.