HV Cable Terminal Lead Seal

Contact area ≥10%

This lead-sealed terminal reveals the mechanism of aluminum sheath floating voltage and discharge caused by defects via equivalent circuit and experimental validation.

Xia, Rong · Qiang, Xu · Yang, Tianyu · Yaqun, Li · Jianjun, Yuan · Shuaiqi, Gao · Yinze, Wang

Lecture Notes in Electrical Engineering 2025

Specifications

Min allowable contact area at lead seal

{'zh': '10', 'en': '10'} %

Advantages

Defines minimum contact area

Interlayer defects reduce the contact area between aluminum sheath and lead seal; the minimum allowable contact area is about 10%, providing a threshold for defect severity.

Reveals floating voltage mechanism

Fracture of the lead seal makes the connection between aluminum sheath and tail pipe unreliable, causing floating voltage of the aluminum sheath, which serves as a signature for defect identification.

Enables defect simulation diagnosis

An RLC equivalent model based on lumped parameters is combined with COMSOL capacitance calculation and measured resistance to analyze voltage and current variation under defects, validated by actual fault cases.

Applications

• HV cable accessory manufacturing：Ensure lead seal contact area ≥10% to prevent floating voltage.
• Cable terminal installation & QC：Inspect lead seal contact area and connection reliability during installation QC.
• Grid equipment defect diagnosis：Diagnose lead seal fracture or interlayer defects from voltage/current signatures to prevent discharge.