Fault Location Techniques for Distribution Systems

1
Fault Location Techniques for Distribution
Systems
Paper 3.49

• 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 gt limited requirement for feeder
  modeling
• accurate gt need for detailed feeder modeling
• measurement requirements
• from the faulty feeder
• from incoming bay gt 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