Fault analysis and model-based approach for fault location in modern grids

Short-circuit faults are inevitable on transmission and distribution networks. Dispatching the maintenance crew directly to the location of the fault saves a significant amount of resources in the restoration process, which has motivated the development of several fault location approaches. Impedance-based fault location (IBFL) approaches are the most commonly used fault location methods in digital relays. However, each IBFL approach is designed specific to a line or network configuration and is not universal. Furthermore, they suffer from several sources of errors and do not fully utilize valuable information about the power system surrounding the faulted line that is available. This dissertation presents a novel fault location approach that utilizes a system model to overcome these limitations. The concept of the proposed model-based fault location (MBFL) approach is to estimate the fault location by identifying the closest match among various fault scenarios simulated using the system model and the actual fault scenario. A key benefit of the proposed approach is identifying the location of a fault on a neighboring line using limited measurements, as few as only the through fault current flowing in a neighboring line. Application methods for implementing MBFL efficiently and effectively have been developed, with each technique having its unique benefits. The advantages of the proposed MFBL approach and the practical applicability of each implementation technique have been demonstrated using simulations on complex network configurations as well as field data of fault events. This work also contributes towards tools to supplement fault analysis applications in ac and dc systems. An algorithm to select an appropriate time instant in a fault record to extract phasors for post-fault event report analysis applications was developed. In low-voltage dc distribution systems, fault signatures of series-arc faults were identified to aid arc detection. Overall, the research work presented in this dissertation makes substantive contributions to fault location and fault analysis in transmission and distribution systems.Electrical and Computer Engineerin