Experimental recurrence of an unreported fire risk of power cable: Discharge of bracket cable metallic grounding under coupled vibration conditions

• Published in: Electric power systems research Vol. 238; p. 111033
• Main Authors: Huang, Beisi, Liu, Gang, Li, Hongfa, Chen, Siting, Lian, Jiehui, Guo, Deming
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2025
• Subjects: Aluminum sheath; Cable fire; Metallic grounding; Power cables; Spark discharge; Metallic grounding; Aluminum sheath; Power cables; Spark discharge; Cable fire
• ISSN: 0378-7796
• DOI: 10.1016/j.epsr.2024.111033

•Under the condition of coupled vibration, the metal grounding fault point of the bracket cable may experience discharge.•The paper has accomplished the experimental recurrence of the discharge occurring between the aluminum sheath of the power cable and the grounded metal bracket, under the influence of coupled vibration.•Vibration can produce electric sparks and even form an AC arc between the aluminum sheath and grounded metal bracket, which is a potential fire hazard.•The paper used a high-speed camera to capture the physical process of vibration discharge. In environments like bridges and tunnels, power cables are laid on metal brackets (hereinafter referred to as bracket cables). If the aluminum sheath and metal bracket form a metallic grounding fault, the air gap near the contact point may bear an intermittent discharge under the cable vibration, which is a potential source of cable fires. However, current research on cable grounding systems does not focus on analyzing the physical metallic grounding process. Discharge from coupled vibrations has been overlooked. This study accomplished the experimental recurrence of discharge at the metallic grounding point of cables under coupled vibration. According to the experimental observations, intermittent electric sparks and AC arc occur with the contact and separation of the aluminum sheath and the metal bracket due to vibrations. Under coupled vibration conditions, metallic grounding faults in cables pose a risk of causing cable fires.