In modern interconnected power systems, 70-90% of faults in high voltage transmission lines are intrinsically transient . the necessity of rapid fault clearing has resulted in fast development of protection equipments . moreover , need for reliable supply of loads has led to improvements in single phase auto-reclosing equipments . In this paper , an appropriate approach is proposed to diagnosis fault type ( transient or permanent ) and the extinguishing time of secondary arc in HV transmission line , leading to improved performance and efficiency of single phase auto-reclosing . In the occurrence of permanent faults, the proposed method is accurate and authentic .Various simulations in EMTP/ATP environment have been shown that the proposed approach is a comprehensive protective algorithm for high voltage transmission line .
