1. CAREER EPISODE-3
I. Introduction:
THE CHRONOLOGY: November 2009-April 2010
GEOGRAPHICAL LOCATION: CHENNAI, INDIA.
NAME OF THE ORGANISATION: ST.JOSEPH’S COLLEGE OF ENGINEERING
POSITION: STUDENT
TITLE: Dynamic Control of a three phase AC motor System with respect to a Linear Relationship.
[CE 3.1]
Among the recent electrical innovations, I learned that AC motors are arguably one of the
most important electrical device and manufacturing industries use motors in almost all the stages
of their operations. They play a vital role in industries and I understood that efficient and advance
control of motors could help industries improve their productivity and achieve higher overall
efficiency. I read through several industries operation such as the paper mill rolling industries
where a minute error in the operation of the motor could lead to improper rolling and severe loss
to their overall outcome. This led me to firmly believe that improved dynamic control system will
drastically help these industries. To achieve a better understanding of the control mechanism and
develop an improved system I worked on this small lab assignment which was part of my Electrical
machines assignment for four months. I was assigned to work for this laboratory assignment under
the supervision of Mr. Elavarasan Kanan, Associate Professor, Head of Department (Laboratory),
Electronics and Electrical department, St. Joseph’s College Of Engineering, Chennai.
II. Background Research
[CE 3.2]
I firmly believe that practical experience would help me better understand theoretical
information from my books. Hence I grasped the opportunity presented by my laboratory head of
the department to work on this real time experience. I volunteered myself in this mini laboratory
assignment to put in practise my acquired academic skills. Several of my classes and laboratory
sessions such as Electrical machines, electrical measurements, electrical circuit’s lab and a private
diploma course which I had enrolled in during this period on Industrial Automation helped me

2. understand and develop this assignment. I designed a predictive dynamic control system for a
simple process on a real time basis which can be applied in an industrial field. The control system
takes physical measurements in terms of Temperature, Frequency and RPM of a three phase
induction motor in order to maintain the temperature of the canister at the desired level and increase
the efficiency of the three phase motor which is a part of the temperature control system. Here the
temperature controlling part can be replaced with any sensor to alter my system, ultimately
achieving better motor control. I initiated my work by starting with the background study from
various online standard journals and official publications. After I started my background study, I
was interested in exploring more relevant content from online resources.
[CE 3.3]
 Developing a brief outline of the assignment and gathering of ideas to develop an effective
and improved system.
 Coordinating with my internal supervisor to develop an elaborate strategy for my
assignment prior to conducting a detailed literature review for my assignment.
 Perform several duties such as coding, stimulation of the project and hard wiring of the
entire system for display.
 Prepare assignment Report.
[CE 3.4]
Firstly my background study was given great importance and an understanding of the
fundamental principles of electrical theories was my primary aim. Later I was introduced to several
electrical appliances and their principal of operations. With this help I was able to conduct in-depth
research on my mini laboratory assignment and shared my research findings with my project
supervisor in my meetings and during the weekly presentations update headed by him. These
meeting and presentations helped me to gather more ideas and suggestions from my supervisor.
Then I narrowed the various suggestion and ideas presented to develop a control system and
drafted a rough project goal and tasks to be undertaken. I constantly utilised my Head of the
department for guidance, for the better understanding of my study from several books and internet
based materials.
[CE 3.5]
I planned the project activities under the supervision of Mr. Elavarasan Kanan, Associate
Professor, Head of Department (Laboratory), Electronics and Electrical department, St. Joseph’s

3. College Of Engineering, Chennai. Also the course I undertook during this time with PROLIFIC
LTD. in industrial automation helped me achieve this project.
.
[CE Fig 3.1] Team Organization
III. Personal Engineering Activity:
[CE 3.6]
After a detailed research on electrical machines, control methods, their operations and
several existing systems, I narrowed down my research to develop an idea for my proposed system.
I designed a flow chart with my supervisor’s guidance and established the scope of my project.
The main idea of my project which I discussed with my supervisor was to program and analyze
the operation of a closed loop control system on a real time basis. I learned that widely used control
systems for similar control operations have their motor speed predefined or turned ON and OFF
constantly because the user is involved with the control procedure and corrective action is done
based on the output value, which reduces the efficiency of the system. I proposed a system to
achieve higher motor efficiency, where in addition to the two position and feedforward control
Electronics and Electrical department
ST.Jospeh’s college of
Engineering
Assoc. Professor
Mr. Elavarasan
Kanan
(Jayaram.K.S.S)
Electronics and
Instrumentation
Engineering
Prolific Limited:
Industrial
automation diploma
course

4. loops (simple slope formula based control loop), a tachogenerator measures the RPM value of the
motor and sends it to a micro master 440 frequency generator which generates a value with respect
to the RPM. This value is sent to the PLC, where the PID control blocks along with several other
blocks which I proposed to program and calibrate, predicts the corrective action required. Then
the controller sends a signal through the generator’s output to alter the speed of the motor. Thus,
the system works continuously as the PLC program predicts the change in temperature which
might occur due to the error in the measured RPM, rather than waiting for the output signal. Thus,
the motor that acts as the temperature regulator achieves higher effectiveness, and the entire control
system obtains an improved efficiency. Thus, I started my work to develop and configure this
entire control system. I also proposed to develop my skills to effectively acquire data and design a
SCADA interface to provide users to monitor and modify the set of parameters for the control
system. I divided the implementation work into three stages as, the system control designing stage,
hardware interfacing and implementation stage, and finally the testing stage. I carried the first and
second stage simultaneously as it was easier to understand my system. I was able to track the
progress of the each activity by maintaining an assignment development document which was
updated regularly and the hardware and software to be considered for this system was discussed
with my supervisor before implementing.

5. [CE Fig 3.2] Flow chart
[CE 3.7]
During system control designing stage, I learned in detail the various theories of electrical
and controls engineering. I used a Siemens S-7 300 controller for the control procedure for my
system. I had to initially learn the basic ladder logic programming to code the Siemens software.
Then I had to read and learn with my supervisor’s guidance advance control procedures and
techniques to implement in this system. Later, I used the software SIMATIC S7-300 for
configuring my control system on several levels. I learnt the PIN configuration and planed the
input and output signal configuration for various equipment to interface to my controller.
START
Auto
LM 35
SCADA
PLC
Frequency Converter
(V/f)
Three
Phase
Motor
Set speed
No
Analog I/P
Analog O/P
Selector S/W
Manual
Tachogen
FEEDBACK
FEEDFORWARD
Yes

6. Controlling codes as mentioned above was done with three control loops. In addition to this, I
included certain interrupt procedures to benefit the execution sequence of the process. I configured
the system in such a way that if any fault on the controller might arise, the system will refrain from
stopping its execution and going into a fault mode but instead would identify the fault to the
operator and then carries on with its procedure with the rest of the unaffected blocks. I stimulated
this program and it was successful. Next step was to download the computer program on to the
controller, for this I used the Open Process Protocol (OPC) standards and Siemens S7 MPI as the
device driver to send and receive data from the controller. I had used (OLE) and (DDE) to create
interfaces for the user to monitor and modify the process. I also created a SCADA using Intouch
software from Wonderware factory suite. I designed and represent my control system in SCADA.
Once the interfacing with the controller was achieved, I downloaded the control program and
executed it successfully.
[CE 3.8]
In the next phase, hardware interfacing and implementation was the priority. Here first I
had to study in depth the various hardware equipment to be used such as the LM35, VFD, tacho
gen, 12V fan, push buttons, relays and LED’s. I had to understand the PIN configuration and the
input and output requirements to interface it with the PLC. Once I learned this, I was able to apply
it to the programming section. I used a bulb as a heating element placed inside the cansiter with
the knob to regulate its intensity and a LM35 temeprature sensor to sense the temeperature. I used
a three phase indication motor which is attached with an exhaust fan for removing excess vapor. I
used a Simens Micromaster 440 AC drive to interface the various operations in my project.I
hardwired all these equipment together and interfaced it with the controller.
[CE Fig 3.3] Hardware setup

7. [CE 3.09]
The final stage was the testing, initially I faced few challenges such as the copper leads in the
LM35 temperature sensor. They tend to measure the temperature of the surface they are placed on,
this was corrected. Few minor difficulties in downloading the program to the controller were faced
but with my supervisor’s guidance I was able to execute the assignment successfully and submit
an assessment report.
[CE 3.10] Summary:
 I was able to successfully execute a system with improved dynamic control system and
specifically improve the efficiency of a three phase motor.
 I boosted my familiarity in electrical engineering.
 I learned the importance of detailed research and learned the art of undertaking focused
meaningful research to achieve my goal.
 My time management skills were improved through project tracking applications.
 My demonstration skills increased after handling the development work and presentation
to my supervisor. I was also given an opportunity to demonstrate my project to my class
member who raised several challenging question regarding the control and operation part
which I explained in detail.