Description
ABSTRACT
Protection system is needed in every industry to avoid unwanted faults in the process components that may leads to excessive downtime and huge losses in terms of maintenance cost and loss of revenue. Protection of induction motor parameters under various operating conditions plays a vital role in its performance, reliability, efficiency and life cycle. This research focuses on the design of a system for measuring and monitoring of voltage, stator current and winding temperature of an induction motor under operation. The system also isolates the motor from the supply if threshold values are exceeded by using sensor technology with PIC18f4550 micro-controller. The hardware system was tested with a single phase induction motor. The results obtained show that the measured values conform to analog meters readings. The system adequately monitors and is olates the induction motor to prevent it from breaking down.
Keywords: Induction motor,Micro-controller,Monitoring,Protection, Sensor
TABLE OF CONTENTS
COVER PAGE
TITLE PAGE
APPROVAL PAGE
DEDICATION
ACKNOWELEDGEMENT
ABSTRACT
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE PROJECT
- PROBLEM STATEMENT
- AIM/OBJECTIVE OF THE PROJECT
- SCOPE / LIMITATION OF THE PROJECT
- APPLICATION OF THE PROJECT
- SIGNIFICANCE OF THE PROJECT
CHAPTER TWO
LITERATURE REVIEW
- OVERVIEW OF INDUCTION MOTOR
- BASIC PARTS OF AN INDUCTION MOTOR
- TYPES OF INDUCTION MOTORS
- ADVANTAGES OF INDUCTION MOTOR
- REVIEW OF RELATED STUDIES
CHAPTER THREE
METHODOLOGY
- BLOCK DIAGRAM
- VOLTAGE MEASUREMENT AND MONITORING
- CURRENT MEASUREMENT AND MONITORING
- TEMPERATURE MEASUREMENT AND MONITORING
- MEASUREMENT AND CONTROL SYSTEM DEVELOPMENT
- MEASUREMENT AND CONTROL SYSTEM IMPLEMENTATION
CHAPTER FOUR
4.1 RESULT AND DISCUSSION
CHAPTER FIVE
- CONCLUSION
- RECOMMENDATION
REFERENCES
CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Induction motors are the most widely used electro-mechanical devices in a variety of applications and since the squir relcage induction motor is low-priced,simple,robust,and rugged,it is considered worldwide as the workhorse in industrial applications (Chaturvedi, Akash, Mayank, and Sharif, 2014).Many researchers focused on condition monitoring of three induction motor components: the stator, rotor and bearings. Little attention has been paid to voltage unbalance in the motor supply and the development of induction motor parameters monitoring system(Mirabbasi,Ghodratollah,and Mehrdad,2009).
Operation of induction motors at voltage and frequencies other than the nominal values, sudden increase in load or load thrown off can cause significant changes in the motor speed. Increase in speed leads toincrease in operating temperature and decreases the functional horse power, which leads to reduced life of motor(Pari,Kavipriya,Naveenadevi,Preethiand Suryadharsini,2017).Induction motor speed and temperature is more affected by high amplitudes of voltage fluctuations, whilst the torque and efficiency are more affected for middle and high amplitudes(Zhao,Ciufoand Perera,2012).
A temperature protection system is needed to protect induction motor stator winding against thermal overloads in an application where induction motors are frequently started, overloaded and used in high inertia applications with long starting times (Aleksejs, 2015). Thermal overheating degrades the chemical stability of the materials used for stator winding insulation and accelerates the aging process. Unbalance voltage can occur due to Intermittent load or strong fluctuations in power demand, presence of larger single-phase consumers, (Zhao, Ciufo and Perera, 2012), presence of higher harmonics in the supply voltage(Miloje,2012).
Thepresentdayrequirementforeverincreasingreliabilityofelectricalmachinesisparametersmonitoring and protection against variations. Though, it does not remedy the fault in most cases but early detection of variations in voltage, current and temperature and appropriate action would eliminate subsequent damage to motor,then reducing the cost of repair and down time. The traditional measuring apparatus like meters cannot give a continuous measuring, monitoring and storing results of induction motor parameters (Shub hang and Rajesh, 2011).
Hence,a cost effective,reliableandaccuratehardwaresystemisdesignedtohaveacontinuousmonitoring of these parameters and protect against variation in voltage, current and temperature and is olate the induction motor from supply if the thres hold value is exceeded.
1.2 PROBLEM STATEMENT
Induction motors are widely used in industrial, commercial and residential systems, because of their ruggedness, simplicity and relatively low cost. Approximately 65% of the electricity consumed in industry is used to drive electrical motors. Therefore, the efficiency and reliability of induction motors operation is of major importance, in order to improve the energy efficiency in industry (Quispe et al, 2011). Squirrel cage induction motors are the most important AC machines in industry. Low cost, high reliability, low inertia and high transient torque capacity are among the advantages of these motors. Many resources show that 35%–45% of motor failures are caused by stator insulation breakdown. For small induction machines, thermal overloading (which can cause high temperature), under or over voltage/current are causes of the induction motor stator winding insulation degradation process (Bonnett et al., 2012).
Thermal devices and models, which assume fixed thermal characteristics of the motor, are not capable of providing sufficient thermal protection since they have no means of giving a correct temperature estimate when the thermal characteristics change. Therefore, in order to extend the insulation life of the induction motor, it is critical to monitor the stator winding temperature, voltage, current and protect the motor under thermal overloading conditions such as motor stall, jam, overload, unbalanced operation, and situations where the cooling ability of the motor is accidentally reduced (Farag et al., 2014).
1.3 AIM AND OBJECTIVES OF THE STUDY
The main aim of this work is to build a system that will analyze and alarm an abnormality of the motor and prevent the damage in case of unbalance voltage or current and high temperature. The objectives of the study are:
- To protect induction motor from breaking down
- To build a protection and monitoring system for industrial induction motor
- To ensure safety of an induction motor.
- To improve the efficiency of the induction motor.
1.4 SCOPE / LIMITATION OF THE PROJECT
This work is on protection and monitoring system for industrial induction motor. This scheme can alert the operation of the motor in order to prevent damage and to extend the life time reducing maintenance costs. It consists of several sensor devices andcoordinatordevice.Thecoordinatordevicereadssensormeasureddatawhichlocatedininductionmotorandtransmits them to the LCD, mikroC source code for PIC libraries is the software used for data acquisition,conversion,communication and display.
Faults result in loses in the motor and also leads to increased electricity charges due to poor power factor, reduced efficiency, and power consumed. This paper is limited to motors operating directly on sinusoidal power and not through adjustable speed drives.
1.5 APPLICATION OF THE PROJECT
This device can be used in the following places:
- workshops
- industries
- electronics hobbyist, etc. for protecting, and monitoring of an AC motor
1.6 SIGNIFICANCE OF THE STUDY
This research work will throw more light on the best techniques for controlling and monitoring an induction motor. This study will also be designed to be of immense benefit to all the users of electric motor most especially in industries.
It will also serve as a guide to whoever that wants to purchase an induction motor.
Finally, it will also serve as a useful piece of information for both producers and users of electric motor.
CHAPTER FIVE
5.1 CONCLUSION
The developed measuring and monitoring system is simple and robust in design, it is reliable and cost effective. The system gave quick response to changes in monitored parameters. Relay activation when the thres hold values are exceeded will improve the performance of the motor. The constant monitoring and measuring can produced ata-base for scheduling of the motor servicing, trouble shooting and future reference; this results to an improved motor’s lifespan. The system can also be used for on-line condition monitoring and fault diagnosis of induction motor with the in corporated relay and alarm system.
5.2 RECOMMENDATION
The device has been designed, tested and system was able to respond to its operation. This work was built with quality wiring and contains many connections, I recommend that if failure occur, it should be troubleshoot by a qualify personnel along with the circuits diagram.
This project was built for Educational purposes. If one wants to use it for industrial or home applications, I recommend that a hook should be attached to the casing that would allow fixing the system on the wall.
Working on this topic as my project is a good idea and it comes at the right time. I am suggesting that this particular topic should also be given to other students both in higher and lower class.
