Adaptive current protection for three-phase short-circuit faults in active distribution networks

Abstract

To address the impact of distributed generation (DG) access on the traditional protection configuration methods of distribution networks (DNs) and to facilitate the swift and effective protection of lines by protection devices under fault conditions, an adaptive current protection method for three-phase short-circuit faults in active distribution networks (ADNs), based on local information, is proposed. Initially, the applicability issues of traditional protection are examined, and the limitations of the existing protection scheme in ADNs are highlighted. Subsequently, the fault characteristics of ADNs are analysed, taking into account the output characteristics of DGs under short-circuit faults, which form the foundation for the proposed protection method. Following this, an adaptive current protection method based on local information is introduced, utilizing a dual criterion of phase and magnitude to adjust line protection, with a specific implementation strategy for the protection scheme provided. Finally, the proposed protection scheme is validated using PSCAD/EMTDC simulation software, with results demonstrating that the scheme enables rapid and efficient protection action under fault conditions across the entire line.