Faulted Branch Location in Distribution Networks Based on the Analysis of High- Frequency Transients

Electric Power Distribution Systems (EPDS) are steadily growing in both size and complexity, and thereby faults on distribution feeders tend to affect more customers and take more time to be located and fixed. Hence, fast and accurate fault location is of primordial importance in minimizing the economic loses for both customers and utilities. Some methods such as those based on the apparent impedance analysis are able to accurately identify the fault distance from the local terminal. However, as the distribution systems have multiple branches and monitoring infrastructure is usually limited to the substation, the location of the faulted branch is a problem not solved yet. This paper proposes the transient analysis of the fault-generated traveling wave in order to identify the faulted branch of radial distribution feeders. The method is based on the correlation of theoretical frequencies calculated for each wave propagation path and characteristic frequencies inferred from the transient spectrum. A frequency-dependent modal transformation matrix is formulated by modifying the Carson's equations thus allowing to accurately model the propagation of high-frequency transients in unbalanced distribution networks. Aiming to verify the performance of the proposed methodology, simulations were carried out considering several fault scenarios in the IEEE 13 nodes distribution system.