Adaptive Single-Terminal Fault Location for DC Microgrids

TL;DR

This paper introduces a robust, communication-free single-terminal method for accurately locating faults in DC microgrids, especially effective for low resistance faults, using local measurements and mathematical analysis.

Contribution

It presents a novel single-terminal fault location technique that is robust to parameter variations and does not require communication, improving accuracy over existing methods.

Findings

Method outperforms existing single-terminal approaches in accuracy.

Robust against variations in fault resistance and location.

Validated through MATLAB simulations.

Abstract

Identifying faulty lines and their accurate location is key for rapidly restoring distribution systems. This will become a greater challenge as the penetration of power electronics increases, and contingencies are seen across larger areas. This paper proposes a single terminal methodology (i.e., no communication involved) that is robust to variations of key parameters (e.g., sampling frequency, system parameters, etc.) and performs particularly well for low resistance faults that constitute the majority of faults in low voltage DC systems. The proposed method uses local measurements to estimate the current caused by the other terminals affected by the contingency. This mimics the strategy followed by double terminal methods that require communications and decouples the accuracy of the methodology from the fault resistance. The algorithm takes consecutive voltage and current samples, including the estimated current of the other terminal, into the analysis. This mathematical methodology results in a better accuracy than other single-terminal approaches found in the literature. The robustness of the proposed strategy against different fault resistances and locations is demonstrated using MATLAB simulations.