A New Algorithm for Two-terminal Fault Location Based on Distributed Parameter Line Model

Abstract

This paper presents a new algorithm for two-terminal fault location in transmission line. It creates a fault-based information ranging function. According to the characteristic of the function, it analyzes the trajectory of function vector and finds the failure point the by recursive function. It uses PSCAD and MATLAB to simulate and prove its correction. Introduction Under the conditions of transmission lines system parameters known, the voltage and current of both line ends are functions of fault distance when a fault occurs on one point of transmission line.Failure analysis method is a common fault location algorithm and it an be achieved with existing fault recorder purposes ranging. It Establishes fault location equations according to system parameters and electrical quantities of measuring points,then calculates the distance between failure point and measuring points. There are two types of failure analysis used for fault location. Single-ended fault location[1-10] uses only one end of the line current and voltage information to determine the fault distance.It does not need the channel to transmit opposite side data, so it is not limited by communication technology. Fault location algorithm using single-ended data can be divided into three categories.The first is the method for solving differential equations.The second uses power frequency electrical quantities to locate fault position.The third finds the fault location according to the characteristics of the voltage distribution along the line under fault conditions.Double-ended fault location[11-17] has sufficient or redundant location equations. It may achieve precise fault location because it can eliminate measuring error affected by transition resistance and other factors. This paper presents a new double-ended locating algorithm which is based on distributed parameter line model.The method is to create a fault-based information ranging function,and to calculate ranging by a characteristic of ranging function up to the minimum when the independent variables is fault distance by trajectory of function vector. Algorithm principle Assuming the transmission lines is uniform and its parameters are constant,we use distributed parameter line mode shown as figure 1.