Analysis of Transients Recorded by Numeric Relayin 220/ 400 kV system

An electric power system comprises of generation, transmission and distribution of electric energy. Transmission lines are used to transmit electric power to distant large load centers. The rapid growth of electric power systems over the past few decades has resulted in a large increase of the number of lines in operation and their total length. These lines are exposed to faults as a result of lightning, short circuits, faulty equipment, mal-operation, human errors, overload, and aging. The un-interrupted and reliable power supply in the need of the today world. Faults cause short to long term power outages for customers and may lead to significant losses especially for the manufacturing industry and nation`s economy as a whole . Fast detecting, isolating, locating and repairing of these faults are critical in maintaining a reliable power system operation. The symmetrical faults (LG, LLG, LLL/LLLG and transients) are most commonly occurring faults in power system. Amongst the all the faults discussed above the behavior of the transient in power system is most unpredictable. This paper aims to provide an insight for the recognition of the transients fault in the power system using FFT analysis.