Accurate Fault Location Estimation of High Voltage Transmission Line Using Disturbance Record

This paper provides a fault location technique for overhead transmission line when disturbance fault recorded data is accessible from both terminal. Numerical relay estimates the fault location based on one end data without compensating the effect of fault resistance; also it does not consider the contribution of remote source, which introduces error in fault location estimation for ground fault. Inaccurate result increases fault finding time, operating cost, revenue loss and affect the Reliability and Availability Index of Transmission system. This error can be reduced using two end data. This paper presents a technique developed to determine the fault location using pure fault voltages, currents obtained from disturbance recorder with two terminal unsynchronized data. Different fault cases are considered from the event recorder of a private transmission network and presented. The fault location is estimated based on positive sequence network using the three-phase current and voltage phasors. Results are compared with the actual fault distance spotted during post fault patrolling. The accuracy of fault location using one end and two terminal data are also compared. Two terminal algorithm is more accurate compared to one terminal algorithm because it is not affected by fault resistance and reactance.