1. 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

2. 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

3. 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

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

5. 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%

6. 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