Fault Location Techniques for Distribution Systems Paper 3.49 Fault Location Techniques for Distribution Systems R. Das, ABB USA M. M. Saha, ABB Sweden P. Verho, ABB Finland D. Novosel, ABB Switzerland

Fault Location in Electrical Network Distance estimation methods Long tradition in transmission level Increasing need in distribution level Problems in distribution network Non-homogeneity of lines Presence of laterals and taps Earth faults in isolated and compensated networks The paper reviews some methods for distribution network fault location

DMS Based Fault Location Distribution Management System (DMS) Application based on integration of SCADA and network data Fault location is one application (in addition to e.g. restoration) Finnish solution Comparison of registered and calculated fault current Excellent practical experience Problem – Earth fault location General model for control center application

Instructions for restoration operations Geographic view of faulted feeder Showing possible locations of fault

Advanced Impedance Based Fault Location Methods Three methods reviewed (Novosel, Das, Saha) Differentiating characteristics load modeling method simplified => limited requirement for feeder modeling accurate => need for detailed feeder modeling measurement requirements from the faulty feeder from incoming bay => only one locator needed Based on simulation the accurate modeling reduces the error from ~10% to ~2%

Conclusions Fault location in distribution network is a challenge Methods vary depending on Required measurements Network modeling Types of networks In practical application there is both local (bay-level) and control center level application