International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056
Volume: 03 Issue: 04 | Apr-2016 www.irjet.net p-ISSN: 2395-0072
© 2016, IRJET ISO 9001:2008 Certified Journal Page 267
Study Of PLC & SCADA Controlled Thermal Power Plant
Akash R. Jaiswal
1
, Prof. P.P Jagtap
2
,
1
GHRCE Nagpur
2
Professor, Dept. of Electrical Engineering, GHRCE Nagpur, Maharashtra, India
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Abstract - Thermal power plant consist of many
important equipment which is required for the
generation such as boiler ,coal conveyer belt ,ash
handling plant ,cooling system etc. These equipment
requires continuous inspection and monitoring .this
paper outlines the automation of boiler &coal conveyer
.Automation leads to greater efficiency &reliability .The
automation is achieved by using PLC&, SCADA. PLC &
SCADA is connected through communication cable .This
paper focuses on passing the inputs to the equipment so
that equipment operation must not get affected .SCADA is
used for monitoring the operation of equipment and PLC
is used to control the operation . The different sensors are
used to sense different parameter such as temperature,
pressure, tearing of belt, overloading, water level etc. If
the parameter exceed the predetermined value the n it is
informed by SCADA system to the operator.in order to
automate the boiler and coal conveyer belt the ladder
logic is developed. The SCADA screen shows the status of
equipment so that operator can take necessary corrective
action. In case of emergency different automated check
valves are used to release pressure, steam and inform the
concerned authority through alarm.
The most common Faults in coal conveyer belt are belt
tear up fault, moisture content and overloading fault
Key Words: Communication cables, Programmable Logic
Controller (PLC), Power Plant, Supervisory Control and
Data Acquisition system (SCADA)
1. Introduction
In thermal power plant the demand for higher reliability &
efficiency is increasing. Power plant requires continuous
inspection & monitoring after regular intervals. There may
be chances of errors while measuring at various stages by
human workers. In order to increase reliability the
automation is needed so that overall efficiency of power
plant get improved. The automation is developed by using
PLC &SCADA which reduces the errors caused by human
workers .PLC is programmable logic control. It is used for
implementing various function such as sequencing, timing,
counting, logic, athematic control through analog and digital
input output modules. In order to store the programme in
PLC it must be interfaced to computer via interfacing unit.
The programmed can be implemented through various
languages. In this paper ladder logic is used for
programming .SCADA system is used to supervise a complete
process. The output of different sensors is given to the PLC
which takes necessary action to control the parameter.
SCADA system consist of subsystem such as human machine
interface, remote terminal unit, and programmable logic
control and communication cable. The alarm system is also
provided to inform the operator. SCADA is used to monitor
water level, temperature, pressure using different sensors
and corresponding output is given to the PLC. For controlling
these parameter. In coal conveyer belt the belt tear up,
overloading and moisture content is sense by different
sensors. The sensor used are IR sensor, temperature sensor,
and humidity sensor.
2. Objective
To develop a programming for automation of boiler and coal
conveyer belt and ash handling plant by using PLC &SCADA
.The automation is achieved by developing a ladder logic for
controlling various parameter of boiler, coal conveyer belt,
and ash handling plant.
3 NEED FOR BOILER AUTOMATION
Boiler produces steam at very high temperature. Boiler
requires continuous inspection and monitoring at regular
interval. Boiler steam temperature in thermal power plant is
very high .It is difficult to control boiler temperature
manually as it may cause serious injury to human workers.
The boiler temperature should not be too high or too low. It
must be kept within permissible limits. Various mechanism
are used to control the temperature of boiler so that boiler
works properly. For reliable operation it is necessary to
develop automation for boiler. The automation is achieved
by using PLC & SCADA
3.1 BOILER AUTOMATION USING PLC AND SCADA
In boiler the control parameters are temperature control,
pressure control, and water level control. These parameter
are control by temperature sensor, float switches and
pressure sensors .Temperature sensors are used to sense the
variation in the temperature. Temperature sensor is passive
element. RT pressure sensors are used to sense the variation
in pressure inside the boiler. Whereas float switches are used
to detect the liquid level float switches are available from low
range to high range. Float switch output is given to PLC and