Identification of defects in HV cable sheath based on equivalent impedance spectrum characteristic coding. (September 2021)

• Record Type: Journal Article
• Authors: Lan, Xueke; Zhou, Niancheng; Liu, Min; Sun, Tingxi; Wang, Jian; Wang, Qianggang
• Is Part Of: International journal of electrical power & energy systems. Volume 130(2021)
• Publication Date: 2021-09
• Subjects: Power cable -- Cable shielding -- Condition monitoring -- Sheath current -- Defect identification; Electrical engineering -- Periodicals; Electric power systems -- Periodicals; Électrotechnique -- Périodiques; Réseaux électriques (Énergie) -- Périodiques; Electric power systems; Electrical engineering; Periodicals; 621.3
• DOI: 10.1016/j.ijepes.2021.107008
• Languages: English
• ISSNs: 0142-0615

Abstract

Highlights: The circuit model of the major section of the CB HV cable is established and decoupled, and the identification equations of the equivalent impedance parameters are established. The calculation process is simple and fast. On the basis of the spectrum analysis of the calculated equivalent impedance parameters, a sheath defect identification method is proposed. In the method, the coding map of the characteristic parameters is formed by the criteria of the DC and high-frequency components. Criteria of defects in HV cable sheath based on simple discrete coding are established, and the accuracy of the proposed criteria is verified through simulation analysis. Abstract: In recent years, on-line monitoring and condition-based maintenance of HV cable systems have been extensively investigated to prevent cable fault. By analyzing cable sheath current, sheath defects can be identified. A new method of cable sheath defect identification is proposed in this study on the basis of the coding of the equivalent sheath impedance spectrum characteristics. In the proposed method, the sheath defects are identified by calculating the equivalent sheath impedance spectrum on the basis of the detected currents of the on-line sheath monitoring system. The equivalent circuit model of cross-bonded (CB) HV cable for sheath defect identification is constructed. The three-phase circuit model is decoupled to solve each phase independently in accordance with the CB scheme of the cable sheath. The equations of solving the equivalent sheath impedance are deduced. The criteria of sheath defect identification are proposed using the coding of characteristic parameters of the equivalent sheath impedance spectrum. Finally, a simulation model of the HV cable is built in the Simulink software to simulate 12 types of sheath defects. The simulation results have proven the correctness and efficiency of the proposed method.