Design And Construction Of Electronics Motor Control

ABSTRACT

The speed control of separately excited dc motor is carried out by varying the armature voltage for below rated speed and by varying field flux to achieve speed above the rated speed. This thesis presents the speed control methodology by varying armature voltage using electronics components and a pair of switches by providing control signal to the switches. The main aim of this work is to build an electronics motor control.

TABLE OF CONTENTS

COVER PAGE

TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

CHAPTER ONE

• INTRODUCTION
• BACKGROUND OF THE PROJECT
• PURPOSE OF THE STUDY
• OBJECTIVE OF THE STUDY
• SIGNIFICANCE OF THE STUDY
• SCOPE OF THE STUDY
• APPLICATION OF THE STUDY
• LIMITATION OF THE STUDY

CHAPTER TWO

LITERATURE REVIEW

• DESCRIPTION OF CHOPPER
• PRINCIPLE OF CHOPPER OPERATION
• DESCRIPTION OF AN AC INDUCTION MOTOR
• REVIEW OF OPERATING PRINCIPLES OF AN AC INDUCTION MOTOR
• HISTORICAL BACKGROUND OF AN AC INDUCTION MOTOR

 

CHAPTER THREE

3.0     CONSTRUCTION METHODOLOGY

3.1      INTRODUCTION

3.2      SYSTEM CIRCUIT DIAGRAM

3.3      HARDWARE MODEL

CHAPTER FOUR

TEST AND RESULT ANALYSIS

• CONSTRUCTION PROCEDURE AND TESTING ANALYSIS
• CASING AND PACKAGING
• ASSEMBLING OF SECTIONS
• TESTING OF SYSTEM OPERATION
• RESULT AND DISCUSSION

 

CHAPTER FIVE

• CONCLUSION
• RECOMMENDATION
• REFERENCES

ABBREVIATIONS AND ACRONYMS

AC – Alternating Current

MOSFET-Metal Oxide Semiconductor Field Effect Transistor

DC-Direct Current

PWM-Pulse Width Modulation

MATLAB -MatrixLaboratory

BJT -Bipolar junction transistor

IGBT -Insulated gate bipolar junction transistor

EMF -Electromagnetic field

GTO -Gate turn off thyristor

PI -Proportional -integral

PID -Proportional –integral-derivative

 

CHAPTER ONE

1.0                                                        INTRODUCTION

A large number of motors are being used for general purposes in our surroundings from house-hold equipments to machine tools in industrial applications. The electric motor is now a necessary and indispensable source of power in many industries. The function and the applications of these motors are wide-ranging. For the many applications, starting of the motor plays a major role, which can be done using a wide range of starting strategies.

The purpose of a motor controller is to take a signal representing the demanded speed, and to drive a motor at that speed. The controller may or may not actually measure the speed of the motor. If it does, it is called a Feedback Speed Controller or Closed Loop Speed Controller, if not it is called an Open Loop Speed Controller. Feedback speed control is better, but more complicated, and may not be required for a simple design.

Generally speed control of the motor can be achieved by varying the input parameters of the motor such as current, voltage etc. This can be achieved by various methods such as field control method, armature control method, Ward-Leonard method etc for DC motors and AC motors.

Now a day, by the improvement of the power electronics devices, the flow of power to the motor is controlled by the switching action of the power switches (MOSFET, IGBT, IGCT etc).

The nature of the motor controllerrequirement for an industrial drive depends upon its type. Some drives may require continuous variation of speed throughout the operation, which ranges from zero to full speed, or a over a portion of the range. For most of the drives, however a control of speed within the range of ± 10% of rated speed may be suitable.

The existing methods for the motor control of induction motor are voltage control, frequency control, vector control, changing stator poles, rotor resistance, doubly fed motor.

Recently remarkable efforts have been made in control of single phase induction motor (SPIMD) drives. The main aim of this work is to build an electronic motor control which is a device or group of devices that can coordinate in a predetermined manner the performance of an electric motor.

1.2                                              PURPOSE OF THE PROJECT

The purpose of an electronic motor control is to take a signal representing the demanded starting speed, and to drive a motor at that speed at low cost.

1.3                                        OBJECTIVE OF THE PROJECT Generally motor control of the motor can be achieved by varying the input parameters of the motor such as current, voltage etc. However the objective of this work is to control ac motor speed using electronic components.

1.4                                         SIGNIFICANCE OF THE PROJECT

This work will serve an avenue for becoming familiar with electronics components and electric motor.

Also, this work will serve as a means of learning how to build a motor starter at low cost.

1.5                                                 SCOPE OF THE PROJECT

Conventional methods for starting and speed control of single-phase induction motor need often quite expensive external electrical equipment. Moreover, they require mechanical switches, which are the most troublesome parts.

These switches suffer from mechanical wear, which affects the motor performance. Electronic methods based on using transistors in series with the stator main winding in a bridge topology has been suggested to control the speed of the motor.

 

Starting is still done by a capacitor in with the auxiliary winding. In the literature many authors have suggested and analyzed the performance of single-phase induction motors fed from inverter circuits with space vector pwm. In this case, either single-phase inverter is used with permanent capacitor motors or two phase inverter is used when the capacitor is omitted. Both methods need complicated circuits with high cost. However, an electronics motor starter seems to be an acceptable solution when a wide range of speed control is required. An electronics motor starter is the advance method which are used to obtain variable RMS voltage from fixed AC course. It is used in the application such as light dimmers, industrial heating furnaces and induction motor speed controllers.

1.6                                          APPLICATION OF THE PROJECT

This work is used in the following devices:

• Electronic bikes
• Swing machines
• Robotic controls
• Mobile air condition fans
• Ac operated drill machines
• Winding machines
• Electronic door controllers
• Toys
• Electronic chairs (beauty parlor. Etc.)

1.7                                           LIMITATION OF THE PROJECT

Drawback of this method of dc motor speed control is that they are not able to control the motor speed smoothly at lower levels, and as the desired speed is decreased, the torque of the motor also decreases proportionately. Due to this, at any unpredictable point the motor may just halt very abruptly. Also, during power ON, the motor may just not start up at lower speed settings and may require an initial boost by increasing the setting. Such situations are pretty undesirable and do not constitute an ideal speed control.