Model-Based Approach Integrated with Fault Circuit Indicators for Fault Location in Distribution Systems

Distribution systems can have complex topologies consisting of taps and laterals which make fault location a difficult process. Fault circuit indicators (FCI) are useful devices which aid system protection and fault location by identifying the faulted line section of the distribution system. Impedance-based methods have been traditionally used for estimating the fault location from fault event report. These approaches make assumptions such as all lines in the distribution system being homogeneous and having the same line parameters which can lead to errors in the fault location estimate. However, to overcome the inaccuracy in fault location estimate requires the assistance of a protection engineer to compensate for known errors and calculate the actual distance to the fault from the measurement location which significantly slows down the outage recovery time. This can be overcome by using an automated model-based approach for fault location. This paper proposes an automated approach that uses the distribution system model along with FCI devices with communication capability to accurately estimate the exact fault location. This paper illustrates the benefits of the proposed approach for fault location by comparing it with other traditional methods using a modified IEEE 34 node test system.