Uses of the single-line diagram
The single-line diagram may be used in a number of important
ways in operating and maintaining an industrial or commercial power
distribution system. Frequently, the single-line diagram, with all of the
listed information, becomes too crowded for information to be used
effectively in some of the operating activities.
In those instances, it is wise to produce a set of
single-line diagrams, with each different diagram in the set containing the
pertinent information that is required for a particular activity or set of
activities. Some of the needs for special single-line diagrams are
a)Switching functions.
When the primary use of the diagram is to provide
information to system operators for switching in order to isolate portions for
maintenance or for load control, then only the data required to make the
decisions necessary for system switching are included on the diagram.
Sometimes, when the distribution system is complex, a
separate version of the single-line diagram in block form is more usable than a
complete single-line diagram. This may be identified as a “system operating
diagram”.
b)Load flow control.
This diagram is used exclusively for load ßow control. It
only includes the data that show system component capacities and other data
that pertain to load flow.
c)Relaying and relay logic diagrams.
These single-line diagrams are used to describe the system
protective relay systems. These diagrams are used particularly as logic and
tripping diagrams that may contain a unique language used only to depict the
sequence of relay or system protective component operation under various fault
conditions.
d)Impedance diagram.
This is a single-line diagram that shows the system input
impedance and the impedance of all system components in which the impedance of
each circuit branch is maintained for system short-circuit analysis.
No comments:
Post a Comment