Description
ABSTRACT
In this modern age automation is taking place in every field of life. This automatic DOL starter of 3 phase induction motor is also a work in this automation process. Induction motors find their application in vast field of engineering and daily life. This paper implements a device which provides automation to the 3 phase induction operation. Due to wide range of application induction motor automation in working of induction motor will cover a wide area of automation.
TABLE OF CONTENTS
COVER PAGE
TITLE PAGE
APPROVAL PAGE
DEDICATION
ACKNOWLEDGEMENT
ABSTRACT
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE PROJECT
- STATEMENT OF THE PROBLEM
- AIM AND OBJECTIVES OF THE PROJECT
- SIGNIFICANCE OF THE PROJECT
- SCOPE OF THE PROJECT
CHAPTER TWO
LITERATURE REVIEW
- REVIEW OF MOTOR STARTERS
- OVERVIEW OF DIRECT ONLINE
- REVIEW OF RELATED STUDIES
- CONTROL APPROACHES OF INDUCTION MOTOR
- REVIEW OF VARIOUS METHODS OF CONTROLLING THE SPEED OF INDUCTION MOTOR
CHAPTER THREE
SYSTEM METHODOLOGY
- METHOD
- BLOCK DIAGRAM
- CIRCUIT DIAGRAM
- CIRCUIT DESCRIPTION
- CIRCUIT OPERATION
CHAPTER FOUR
TEST AND RESULT ANALYSIS
- INSTALLATION OF THE COMPLETE DESIGN
- CONSTRUCTION PROCEDURE AND TESTING
- CASING AND PACKAGING
- ASSEMBLING OF SECTIONS
- TESTING OF SYSTEM OPERATION
CHAPTER FIVE
- CONCLUSION
- RECOMMENDATION
REFERENCES
CHAPTER ONE
Introduction
1.1 Background of the study
An electric motor converts electrical energy into mechanical energy. The reverse of this would be the conversion of mechanical energy into electrical energy and is done by an electric generator.
In normal motoring mode, most electric motors operate through the interaction between an electric motor’s magnetic field and winding currents to generate force within the motor. In certain applications, such as in the transportation industry with traction motors, electric motors can operate in both motoring and generating or braking modes to also produce electrical energy from mechanical energy.
Found in applications as diverse as industrial fans, blowers and pumps, machine tools, household appliances, power tools, and disk drives, electric motors can be powered by direct current (DC) sources, such as from batteries, motor vehicles or rectifiers, or by alternating current (AC) sources, such as from the power grid, inverters or generators. Small motors may be found in electric watches. General-purpose motors with highly standardized dimensions and characteristics provide convenient mechanical power for industrial use. The largest of electric motors are used for ship propulsion, pipeline compression and pumped-storage applications with ratings reaching 100 megawatts. Electric motors may be classified by electric power source type, internal construction, application, type of motion output, and so on.
However, for a motor to work or achieve the purpose they are made to do whether in industrial or workshop, they must be controlled. The direct, speed and torque must be controlled by a controller.
Induction motors are widely used due to low maintenance expenditure, good efficiency and fast pick-up, low-cost and sturdy construction. In most of the operations related with 3 phase induction motor, motor not need to run continuously it is required to run for a particular amount of time and in some of the tasks motor is required to be started frequently after a particular time. So with the help this automatic DOL starter of 3 phase induction motor device this purpose can be fulfilled without any extra effort. With the help of this device user just need to feed the amount of time for the motor operation is required or the time after which the motor is required to start,in the device and after the completion of time motor will start or stop on the basis of lever setting provide in the device. This system is designed with the help of microcontroller which works as programmable timer which is the heart of the whole system. As 3 phase induction motor of large size cannot be started directly or with DOL method so in this system star-delta connection space is provide so that the motor can be connection star-delta formation for protection purpose.
1.2 Statement of the problem
When the motor is at idle, it just look like short circuited transformer at secondary side because all the rotor bars are connected together to form a closed path. This will turn a large current flow through the rotor bars. So when the motor is started, stator draws the high current which is 8-10 times that of the motor rated current. Before staring the motor, it is necessary reduce the voltage applied to the motor. The project is designed to provide low voltage start to induction motors. This is achieved by using star to delta conversion. Star/Delta starters are probably the most common reduced voltage starters in the 50Hz industrial motor world. Star delta is used in an attempt to reduce the start current applied to the motor then after sometime full load current is applied to the motor. Since in star connection current is same in different phases while line voltage is the root three times the phase voltage. So the voltage is reduced (results to reduce current) if motor is started as star. And also in delta connection the voltage is same as that of phase voltage so full voltage is applied if we run the motor as delta connection.
1.3 Aim and objectives of the study
The main aim of this work is to build an automatic DOL starter with programmable timer. The objectives of the work are:
- To build the system prototype
- To provide a 3 starting a 3-phase induction motor of large size directly or with DOL method.
- To provide a safer means of running a three phase induction motor.
1.4 SCOPE OF THE STUDY
The scope of this work covers building a device which will provide an automatic means of running or operating an induction motor using microcontroller as the heart of the system.
1.5 SIGNIFICANCE OF THE STUDY
The system serves as a means of operating an induction motor automatically.with this device the user can set time for the starting or stopping of the motor.
With this device, the user has very wide range for time input from 1 sec. to the 9999 minutes.
Since motor will run for required time so this device will save the energy and machine as well.
Ina manual operation of the system, the user has to keep his/her eyes on the watch for motor operation so by using this system he can be free for any other work.
CHAPTER FIVE
5.1 CONCLUSION
This paper proposes an inexpensive and compact model of automatic motor starter using 89s52. Depending upon pre-determined data the signals from microcontroller are conditioned and corresponding output pins are checked for correctness. The system that has been implemented has shown considerable output that matched our requirement. This was achieved by small and user friendly 89s52.
The project has been successfully completed and the main objective of has been achieved.
5.2 RECOMMENDATION
This control system is recommended for every electronics laboratories, and industries to aid those working or living in those places when it comes to repairing their equipments. This control system has to be perceived by the society and the world at large as a necessary and vital technological upgrade.
While working on this design, at some point in time we were carried away by the fact that our project is working as desired but on further thinking, we thought about the fact that our control system should working independently on its own when it comes to the power supply unit, that the system get its power from the public power supply system which is well known that it is not stable, so on this note , we will advice any further work on this control system to have its power supply independent on its own or better still use rechargeable batteries or solar if possible.
