Generalized Impedance-based Fault Distance Calculation Mehtod for Power Distribution Systems

This paper presents a new impedance-based fault distance calculation formulation for power distribution systems. The majority of low-or medium-voltage distribution systems are characterized by having numerous branches, laterals and sub-laterals, highly unbalanced operation, and time varying load profile. All of these and other characteristics make most efficient approaches proposed for fault location in power distribution systems not applicable to distribution systems. The proposed method uses only measurements of voltage and current at the beginning of the analyzed feeder, and additional equipments such as, fault locators and monitoring devices are not needed to be installed in the distribution system. The apparent impedance is calculated by using the fundamental rms values of the measured voltage and current in this paper. This method is suitable to any kinds of fault and can be used to unbalanced power distribution systems, since it is derived in phase domain.