LOCATION OF FAULTED LINE SECTION IN DISTRIBUTION SYSTEM

Abstract

To locate fault in power distribution system various methods are proposed which are iterative and time consuming in nature. Therefore, to speed up the restoration process and to improve reliability at consumer end a non-iterative and fast approach is presented to locate the fault in power distribution system (PDS). This method is applicable to all types of faults. It requires voltage and current measurement at substation node after occurrence of fault and bus impedance matrix of healthy system. Current and Voltage at local substation can be expressed as resistance of fault and location of fault by bus impedance matrix, solution of which yields to fault location. This approach of fault location is applicable to unbalanced system as it is developed in phase domain. It is assumed that distribution system network topology and parameters are known through which bus impedance matrix is developed. To calculate the pre fault bus voltages and currents of each bus unbalanced three phase load flow is utilized which is different from the conventional methods used for three phase balanced transmission system. It requires BIBC (bus injection to branch current) and BCBV (branch current to bus voltage) matrix and a simple matrix multiplication to acquire the appropriate results. Therefore, it eliminates the need of forward/backward substitution of the Jacobian matrix or admittance matrix used in the transmission system load flow methods. Utilizing load flow results bus impedance matrix is developed and then algorithm for fault location is applied to calculate the actual fault location. The method presented is fast, accurate and robust for load variations.