An earth fault diagnosis method based on online dynamically calculated thresholds for resonant ground systems

Lin, Jiahao and Guo, Moufa and Hong, Qiteng and Jiang, Run (2024) An earth fault diagnosis method based on online dynamically calculated thresholds for resonant ground systems. IEEE Transactions on Smart Grid. ISSN 1949-3053 (https://doi.org/10.1109/tsg.2023.3346453)

[thumbnail of RG-An earth fault diagnosis method based on online dynamically calculated thresholds for resonant ground systems.pdf]
Preview
Text. Filename: RG-An_earth_fault_diagnosis_method_based_on_online_dynamically_calculated_thresholds_for_resonant_ground_systems.pdf.pdf
Accepted Author Manuscript

Download (90MB)| Preview

Abstract

The primary problem of distribution system protection is single line to ground (SLG) fault, particularly in networks with distributed generators (DGs), where asymmetrical phase sequence components caused by SLG fault s may lead to system instability. Currently, the location and suppression methods of SLG faults are based on reliable fault diagnosis. Therefore, considering the imbalance of line parameters, this paper analyzes the fault characteristics of zero sequence voltage (ZSV) ZSV), and proposes a threshold online calculating based SLG fault diagnos is method, which includes fault detection, fault occurrence moment capture and fault nature estimation. Firstly, the ZSV is measured in real time by the designed feeder terminal unit (FTU) which is embedded with the pro posed SLG fault diagnosis method. Secondly the ZSV signal is decomposed by the Mallat algorithm and the fault diagnosis threshold s are calculated through the maximum margin hyperplane, which is used for fault detection and fault nature estimation. Finally, the fau l t occurrence moment is captured by variational mode decomposition (VMD) and its T eager Energy Operator (TEO). The proposed SLG fault diagnosis method has been tested in simulation and physical experiments in a 10kV system, the effectiveness and feasibility have been validated.