Electrical Grid System, network topology and power stations

1. Presented by
Dr. R. RAJA, M.E., Ph.D.,
Assistant Professor, Department of EEE,
Muthayammal Engineering College, (Autonomous)
Namakkal (Dt), Rasipuram – 637408
Electrical Grid System
MUTHAYAMMAL ENGINEERING COLLEGE
(An Autonomous Institution)
(Approved by AICTE, New Delhi, Accredited by NAAC, NBA & Affiliated to Anna University),
Rasipuram - 637 408, Namakkal Dist., Tamil Nadu, India.

2. Electrical Grid System.
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 The connection of several generating stations in a network of particular
transmission voltage level is commonly known as electrical grid system.
 By interconnecting different power generating stations we can solve various
difficulties arise in power system.
 The structure, or “network topology” of a grid can vary depending on the the load
and generation characteristics, constraints of budget and the requirements for
system reliability.
 The physical layout is often forced by the geology and land availablility.

3.  Although, forming a grid by interconnecting different generating stations
located at different places is significantly expensive since the protections and
operations of the entire system become more complicated.
 But untill modern power system demands the interconnected grid between the
power stations because of its tremendous benefits against the power stations
which are running individually.
 There are some advantages of interconnected grid system listed below one by
one.
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5.  The interconnected grid increases the reliability of power system significantly.
In case of failure of any generating station, the network (grid) will share the
load of that generating plant. Increased reliability is the most significant
advantage of a grid system.
 The arrangement can exchange the peak load of a plant. In case of individual
operation of a generating station, if the peak load increases beyond the capacity
of the generating station, we have to impose partial load shedding on the
system.
 But when we connect the generating station to a grid system the grid carries the
extra load of the station. There is no need for partial load shedding or no need
for enhancement of the capacity of that particular generating station.
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6.  Sometimes there are numbers of inefficient old generating stations available
with a generating authority which they cannot run in continuous basis from the
commercial point of view.
 If the entire load of the system exceeds the grid capacity, the generating
authority can run these old, and inefficient plants for a short duration to meet
the excess demand of the network. In this way, the authority can utilize the old
and inefficient plants up to some extent without keeping them entirely idle.
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7.  The grid covers a large number of consumers than that of an individual
generating station. So the fluctuation of load demand of a grid is much less than
that of a single generating plant.
 That means the load imposed on the generating station from a grid is much
consistent.
 Depending on the consistency of the load, we can choose the installed capacity
of the generating station in such a manner that the plant can run with nearly its
full capacity for a significant period of time during each day. Hence the
generation of electricity would be economical.
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8.  The grid system can improve the diversity factor of each generating station
connected to the grid. The diversity factor gets improved because the maximum
demand of the grid shared by the generating station is much lesser than the
maximum demand imposed on the generating station if it runs individually.
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9. Thank You
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