A New Transmission Line Differential Protection based on Fault current DC Transients

This paper presents a new transmission line differential protection using fault current DC transients. The behaviour of fault current DC transients for different types of faults are analysed for proposing a new differential protection criteria. The proposed method clearly distinguishes internal and external faults which aids in improving the sensitivity and security of the transmission system. Different types of the fault like solid ground fault, high resistance faults, outfeed effect are considered and compared with the conventional differential protection. For analysing the proposed method a 10 bus system is considered and simulated using PSCAD software. From the results it is observed that the proposed differential protection operates well for different types of network configurations and for various types of faults at a faster fault identification rate