III. PROPOSED DISTANCE PROTECTION SCHEME
To illustrate the setting rules for the distance-based protection
scheme, the radial overhead line distribution system depicted
in Fig. 2 is considered again. The fuses F1-F4 protect
the main laterals, while the fuses F1.r-F.4.r protect the remotest
tapped distribution transformer in each lateral. We assume
fuses at the laterals because they are the most encountered
protection means in overhead distribution lines and because
fuses are more difficult to coordinate with the main feeder
protection (recloser/distance relay) than overcurrent relays due
to their non-settable characteristic. A fuse-saving philosophy
is further adopted. Coordination between the main fuse and
the fuses at the primary of the tapped transformers is assumed.