Analysis of the Reasons and Precautionary Measures for the Live Detection of the 110 kV Main Transformer Side Cable Terminal

Aiming at the defect of abnormal live detection of the cable terminal on the main transformer side of a 110 kV substation,through field test detection and theoretical analysis,it was determined that there was a partial discharge defect in the #102 interval B phase cable terminal of the main transformer 2. Based on the ultrahigh-frequency（ UHF） spectrum and ultrasonic signal detection results,a preliminary judgment was made of the discharge caused by holes/contamination defects. Subsequently,the cable terminal was disassembled and inspected. It was found that there was a significant discharge point between the copper shielding tape and the semiconductor,and the main insulation had burn marks. Therefore,the cable terminal was reworked in strict accordance with the requirements to eliminate the hidden danger of the accident and avoid such accidents. Suggested precautions were given.