In this proposed model automated load shedding can be using microcontroller and relay module. this model is applicable only based on voltage sagging but it can be made based on current only replacing transformer to current transformer.
2. Our aim of this project is designed to control substation load
shedding using a programmable switching control by
automatically.
In this project we demonstrate the working of this simple
operation using a Microcontroller.
The development of this application requires the configuration
of the program through GSM module. In substation, there are
many tasks like certain loads need to be switched on/off .
All the status of loads are displayed on an LCD as well as
serial monitor.
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3. Load shedding refers to a deliberate and selective dropping of
electrical load in accordance with a pre planned program in
order to ensure that plant does not trip off on overload and
also to ensure that certain preselected loads can be saved ,even
though other loads are lost.
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4. Lack of maintenance of generating and distribution
systems.
Increased population
Improved living standards
Lack of planning regarding growth in future
Lack of raw materials , skilled labour, adverse weather
conditions etc.
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5. Prevents instability and system collapse of electrical
generation and distribution systems
Ensures certain consumers have power as compared to
blackout
Loss of revenue
Consumer inconvenience
Restoring load may cause more instability
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7. Operation is reliable
Fixed and accurate time of load shedding
Fast response to disturbance
Easier maintenance
Eliminate unnecessary load shedding
Predicts system response after load shedding
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10. 10
A relay is an electromagnetic switch operated by a
relatively small electric current that can turn on or off a
much large electric current.
WORKING:
When no current flows through the coil the
metal bar lies on ‘NC’.
When current starts flowing through the
coil it produces magnetic field.
Coil behaves as energized electromagnet.
This coil now pulls the metal bar to ‘NO’
11. 11
5V 4-Channel relay interface board and
each one needs 15-20mA driver current.
Equipped with high-current relay,
DC 30V 10A (input)
AC250V 10A (output).
Standard interface that can be
controlled directly by microcontroller
(Arduino, 8051, AVR etc.).
Indication LED's for relay output status.
12. 12
28 Pin IC
5V OperatingVoltage
Digital I/O Pins 14 (of which
6 provide PWM pins)
Contains 6 ADC Pin
Flash Memory 32 KB
SRAM 2KB
Clock Speed 16MHZ
14. A single phase ac supply of 220 v is connected to a
combination of 3 bulbs.
It is also supplied to a single phase transformer ,which steps
down the input to feed into the uncontrolled full bridge
rectifier.
The dc output of the rectifier is fed into analog input of the
microcontroller, according to this analog input microcontroller
on/off the particular relay relay for the purpose of load
shedding.
The output of microcontroller is also fed into a 16x2 LCD for
display purpose and SD card for storage purposes.
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15. Output of the bridge rectifier
Vo=.632(Vm-2Vd)
Our main challenge to find the value of resistances R1 and R2
as well as to obtain dc output.
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16. System is a bit complex as it involves digitalization
and hence requires skilled manpower
Regular maintenance is required
Higher cost of installation
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17. Data saved in SD Card is to be transmitted from
distribution centre to control unit via GSM.
Developement of one phase model into three phase
working setup.
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18. “ Reasons of Load shedding”, Engineering.electrical-equipment.org
“Literature review of load shedding methods”, UK ESSAYS.com
“An Introduction to Power Plant Load Shedding”, J. Paul Guyer , CED
engineering.com
“Under voltage load shedding”, Charles Mozina , Beckweth Electric Co.,
Inc.
“GSM based automatic substation load shedding and sharing using
programmable switching control “,S.R. BAALAN , JSAM
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