Directional element for faulty feeder identification of high‐resistance fault in high‐surety power supply systems

• Main Authors: Roja Rouhani, Iman Sadeghkhani, Josep M. Guerrero
• Format: Article
• Language: English
• Published: Wiley 2021-01-01
• Series: IET Generation, Transmission & Distribution
• Online Access: https://doi.org/10.1049/gtd2.12006
• ISSN: 1751-8687; 1751-8695

Abstract The high‐surety power supply systems are gaining great attention to enhance the reliability of uninterruptable power supplies. A high‐resistance fault along a high‐surety power supply feeder results in a low fault current, making the conventional high‐surety power supply protection strategy ineffective. To address this problem, this paper develops a directional fault protection strategy for high‐resistance fault detection and faulty feeder identification. Using the intelligent electronic device, the feeder current is sampled and normalised. Then, the fault‐imposed component of the current signal is calculated. This component is added to the input of the forced Helmholtz oscillator to increase the sensitivity of the proposed protection scheme for the detection of high‐resistance faults. The output of the forced Helmholtz oscillator equation is adopted as the fault detection criterion because it is infinity for reverse faults while it is lower than 1 for forward faults, facilitating the fault detection. The developed strategy is local and can detect and classify both pole‐to‐ground and pole‐to‐pole high‐resistance faults. Also, it is effective for both unidirectional and bidirectional converters. The merits of the proposed protection strategy are demonstrated through several fault scenarios using a ±375 V high‐surety power supply system.