09-09-2016, 12:01 PM
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ABSTRACT- One of the 8051s many powerful features is
its integrated UART, otherwise known as a serial port. The
fact that the 8051 has an integrated serial port means that
you may very easily read and write values to the serial
port. If it were not for the integrated serial port, writing a
byte to a serial line would be rather tedious process
requiring turning on and off of the I/O lines in rapid
succession to properly “clock out” each individual bit,
including start bits, stop bits and parity bits.
However, we do not have to do this. Instead, we simply
need to configure the serial ports operation mode and baud
rate. Once configured, all we have to do is write to an SFR
to write a value to the serial port or read the same SFR to
read a value from the serial port. The 8051 will
automatically let us know when is has finished sending the
character we wrote and will let us know whenever is has
received a byte so that we can process It. We do not have to
worry about transmission at bit level, which saves us bite a
bit of coding and processing time. In this project, we are
using one Temperature sensor, ADC, Microcontroller
8051, LCD) for displaying the faults and parameters, GSM
board used to send the fault message to electricity board.
By using this project, we can detect the multiple faults of
three phase transmission lines one can monitor the
Temperature, Voltage, Current by means of GSM modem
by sending message.
EXISTING SYSTEMS
Generally when a fault occurs in transmission line,
unless it is severe it is unseen. But gradually these minor
faults can lead to damage of transformer and can turn
havoc to human life. It may also initiate fire.
Present day in India, we do not have a system in hand
that would let us know in real time once a fault occurs.
Matter of concern is that since we do not have a real
time system, this leads to damage of the underlying
equipment‟s connected and turns out to be a threat to
human around.
In order to avoid such incidents to the maximum extent,
maintenance or checking of the transmission lines are generally carried out on a frequent basis. This leads to
increased manpower requirement. The fact remains that
the real intention of this is not met as many a times line
failure may be due to rain, toppling of trees which
cannot be predicted. Like in Western Ghats where the
transmission lines are usually drawn amidst the forest
and places like Chirapunjee where massive rainfall
almost sets everything standstill.
It is necessary to understand the gravity and after effects
of a line failure. To overcome these, we are proposing a
GSM based transmission line fault detection System.
Whenever the preset threshold is crossed, the
microcontroller instantly initiates a message to be sent to
the area lineman and the Control Station stating the
exact pole to pole location. This helps us to realize a
almost real time system.
The real intention of detecting fault in real time and
protecting the transformer at the earliest is realized. It is
important to note that transformers are very costly. An
11KV transformer on an average costs 3000 US$. So
here we are designing a cost effective and fast response
system aiding in improving safety.
FAULTS
In an electric power system, a fault is any abnormal flow
of electric current. For example a short circuit is a fault
in which current flow by passes the normal load. An
open circuit fault occurs if a circuit is interrupted by
some failure. In three phase systems, a fault may involve
one or more phases and ground, or may occur only
between phases. In a “ground fault” or “earth fault”,
current flows into the earth. The prospective short circuit
current of a fault can be calculated for power systems. In
power systems, protective devices detect fault conditions
and operate circuit breakers and other devices to limit
the loss of service due to a failure.
In a poly phase system, a fault may affect all phases
equally which is a “symmetrical fault”. If only some
phases are affected, the “asymmetrical fault” requires use of methods such as symmetrical components for
analysis, since the simplifying assumption of equal
current magnitude in all phases no longer applicable