Fault Location Method for Three-Core Cable Using Amplitude Ratio of Shield-Grounding Wire Currents

With significant technological advancements in power grids, three-core cables are widely employed for their safety and other benefits. In general, three-core cables in medium-voltage distribution systems are laid underground during operation. As a result, the harsh working environment and complex fault conditions can bring massive challenges to fault location issues. To address the problem, the distinctive cable features are extensively considered in this article, including relatively larger capacitance, cable shield effects, and shield bonding methods. Initially, an equivalent cable model is developed to analyze the relationship between shield-grounding wire currents and the fault point. A single-phase grounding fault location method is then formulated based on the ratio of shield-grounding wire currents at both terminals. In power systems computer aided design/electro magnetic transient in DC system (PSCAD/EMTDC), a range of fault scenarios are simulated to verify the proposed method. In comparison to conventional similar approaches, the proposed method exhibits higher accuracy and robustness to fault resistance and diverse fault conditions. Finally, the effectiveness of the proposed method is validated on a real 10 kV distribution network experimental platform under several fault scenarios.

Automated summary

This article discusses the application of three-core cables in medium-voltage distribution systems and the challenges of fault location. The authors propose a fault location method based on an equivalent cable model and the ratio of shield-grounding wire currents. Simulation experiments in PSCAD/EMTDC software show that the proposed method has higher accuracy and robustness compared to conventional approaches. The effectiveness of the method is validated on a real 10 kV distribution network experimental platform.