An Improved Scheme of Active Power Differential Protection for Transmission Line

In this paper, an improved scheme of active power differential protection for transmission line is proposed. The criteria for active power differential protection are optimally designed and described in detail. Restraint characteristic criteria and additional auxiliary criteria are used to solve the "voltage dead zone" issues of active power differential protection. Simulation results show that the proposed protection scheme can accurately identify the fault area without dead zone when metallic ground fault occurs near the protection units. In addition, active power differential protection has the advantage of low data synchronization requirements, and it is verified in this study.