Novel system model‐based fault location approach using dynamic search technique

Abstract

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 thus is not universal. For example, complex line configurations such as lines with mutual coupling between them and three-terminal lines have to employ individual IBFL algorithms derived specifically for them. Furthermore, they suffer from several sources of errors such as non-homogeneous system, and CT saturation. Hence, this paper presents a novel fault location approach that utilises a system model to overcome these limitations. The proposed model-based fault location (MBFL) approach estimates the fault location by identifying the closest match among various anticipated fault scenarios obtained using the system model and the actual fault scenario. It uses a dynamic search technique to implement the MBFL efficiently. A key highlight of the proposed approach is identifying the location of a fault on a neighbouring line using limited measurements, as few as only the through fault current flowing in a neighbouring line. The advantages of the approach and its practical applicability have been demonstrated by implementing it in complex network configurations as well as field data.