A NEW FAULT LOCATION ALGORITHM FOR USE WITH CURRENT DIFFERENTIAL PROTECTIVE RELAYS OF TWO-TERMINAL LINE

Abstract – A new fault location algorithm utilising syn-chronised measurements of two-end currents and one-end voltage is presented. It has been assumed that such fault location algorithm is incorporated into the current differ-ential relay. In this way, the communication between the line ends of differential relays is utilised. By incorporating the fault location function, an increase of the relay func-tionality is achieved. The derived fault location formula is compact and covers different fault types – what requires setting the appropriate fault type coefficients. High accu-racy of fault location is assured by strict considering of the distributed parameter line model. The solution is obtained with applying iterative calculations based on the Newton-Raphson method. For starting the calculations, the solu-tions obtained for the lumped line model are utilised. The performed ATP-EMTP evaluation prove the validity of the presented fault location algorithm and its high accuracy