A high impedance fault (HIF)
results when an energized primary conductor
comes in contact with a quasiinsulating object such
as a tree, structure or equipment, or falls to the
ground. The significance of these previously
undetectable faults is that they represent a serious
public safety hazard as well as a risk of arcing
ignition of fires. A high impedance fault is
characterized by having impedance sufficiently
high that it is not detected by conventional over
current protection, such as fuses and over current
relays. Unlike low impedance short circuits, which
involve relatively large fault currents and are
readily detectable by conventional over current
protection, these HIFs represent little threat of
damage to power system equipment. High
impedance faults produce current levels in the 0 to
85 ampere range. Typically, an HIF exhibits arcing
and flashing at the point of contact. In this paper,
high impedance fault is analyzed and it is modeled
using MATLAB Simulink tool for deploying proper
protection scheme in distribution system.