DESIGN OF PRACTICAL DESIGN AND TESTING FOR DRIVE [PDF]

This project is mainly concerned on DC motor speed control system by designing a drive circuit. It is an open-loop real

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Jazan University College of Engineering Electrical Engineering Department

PRACTICAL DESIGN AND TESTING FOR DRIVE CIRCUIT OF MACHINE USING PULSE WIDTH MODULATION ( P.W.M )

DESIGN OF

By Team Members

1-Nabeel Eshwy

2- Yazead Otaif

3-Shreef Abu AL-Noor

4- Abdullah Kareri

5-Motab AL-Dawsari

6- Ibrahim Osayli

7-Sultan Asiri

8-Tariq AL-Qesi

9-Saeed AL-Taledi

10-Jaber AL-Ma

Supervisor (s):

Dr. Ahmed Oshaba

)2014 / ‫تاريخ التقدم (مايو‬ 1

Jazan University College of Engineering Electrical Engineering Department

PRACTICAL DESIGN AND TESTING FOR DRIVE CIRCUIT OF MACHINE USING PULSE WIDTH MODULATION ( P.W.M ) APPROVAL RECOMMENDED EXAMINATION COMMITTEE :

Dr. Shaban Eladl Dr. Emad Said Dr. Ehab Salm Dr. Ahmed Oshaba

PROJECT SUPERVISORS : DATE : DEPARTMENT HEAD : DATE :

Dr. Ahmed Oshaba _______________________________

Dr. Ziad Tawfiq _______________________________

APPROVED: DEAN, COLLEGE OF ENGINEERING : Dr.Mohammed Nour Bin Nahir Al-Maghrabi DATE :

_______________________________ 2

DEDICATION To our Fathers, who through their financial and moral support were the source of inspiration and the mainstay in our attaining an education, we dedicate this project.

ACKNOWLEDGEMENT This project was written under the direction and supervision of Dr. Ahmed Oshaba , We would like to express our sincere appreciation to him for the interest and assistance given to us.

3

CONTENTS DEDICATION ACKNOWLEDGEMEN CONTENTS CHAPTER (1)

4 5 6

INTRODUCTION 1. Introduction 2. The Development of Power Converters CHAPTER (2)

8 9 10

Classification of Electric Motors 1.Main Types of Motor

12 13

2.Types of DC motors 3. Types of AC motors 4. Speed Control of DC Series Motor CHAPTER (3)

15 21 24

CONTROL OF THE ELECTRICAL MACHINES 1. Introduction 2. Type of DC Motor Control 3. Functions of DC Motor Control 4. Advantages of DC Motor 5. Disadvantages of DC Motor 6. Applications of DC Motors 7. Introduction to Electronic DC Drives 8. Electronic DC Drives: Control Methodology and characteristics CHAPTER (4)

26 27 27 27 28 28 28 29 30 PAGE 31 32 32 33 33 34 35 36 38

CONVERTER

1. Introduction 2. Operation of Converter 3. Applications of Converter 4. DAC types 5. ADC types 6. DC to DC Converter 7. Types of DC to DC Converter 8. Basic Types of Inverters CHAPTER (5) SIMULATION FOR DC MOTOR SYSTEM DRIVE BY USING P.W.M CONVERTER 4

.42

1. Introduction 2. Converter Simulation by Using Mat lab Simulink 3. Simulation of DC-DC Converter 4. Simulation of AC Inverter 5. Simulation of DC Motor is supplied by DC - DC Converter CHAPTER (6)

43 43 43 47 48

PRACTICAL DESIGN, TESTING AND EXPERIMENTAL ORKS

53

1. Introduction

54

2. Drive Circuit of IGBT

54

Chapter (7) CONCLUSION

90

A-REFERENCES B-CAPSTONE DESIGN PROJECT C-APPENDICES B-1: List of components B-2: Integrated Circuits IC's datasheet

91 92 95 96

5

CHAPTER 1 INTRODUCTION

6

INTRODUCTION Introduction This project is mainly concerned on DC motor speed control system by designing a drive circuit. It is an open-loop real time control system; pulse width modulation (PWM) technique is used where its signal is generated by the drive circuit. The PWM signal will send to motor drive to vary the voltage supply to motor to maintain at required speed. A typical electric drive system includes a controller, a transmission, an electric motor and a driven load (e.g., fans, pumps, conveyors and others previously cited.) A key difference in different types of electric drive systems is the type of controller: (A) distinct DC motor control components, such as motor starters, switches and operator controls, or (B) electronic motor controllers, called drive controls, which use semiconductors with electronic circuitry and software to perform the same functions of distinct DC motor control components.

Fig. 1.1: System block diagram.

2. The Development of Power Converters The heart of a switch-mode power supply (SMPS) is a DC-DC converter, which accepts a DC input and produces a controlled DC output. Semiconductor DC-DC converters have appeared in practical use since the 1960s. The three basic types of power converters are the buck, the boost, and the buck-boost converters. The buck converter can work as step-down converter, while the boost converter can work as step-up converter, and the buck-boost converter is working as stepup step-down. The circuits of which are shown in Fig. 1-2.

7

Dfw

(a) Buck converter

(b) Boost Converter

(C) Buck-Boost Converter

Fig. 1.2: Basic square-wave converters.

In 1977, CûK and Middlebrook introduced a new "optimum topology switching DC toDC converter", which is now more commonly referred to as the CûK converter. Fig. 1-3 shows the basic circuit of the CûK converter, which functionally is a cascaded connection of a boost converter followed by a buck converter. Consequently, it works as step-up step-down converter. Various topologies of square wave converters were also studied by CûK , and Landsman . Recently: much attention has been focused on the design of high frequency converters with reduced weight and size , and the use of fast MOS or IGBT power transistors as switching elements .

8

Fig. 1.3 CûK Converter. Since power converters and the SMPS are nonlinear circuits, computer aided analysis and design techniques for such circuits are highly desirable. In the next chapter we will discuss each type of those converters.

9

CHAPTER 2 Classification of Electric Motors

10

Classification of Electric Motors Main Types of Motor: Electric motors are broadly classified into two categories as follows: 1.

AC Motors.

2.

DC Motors.

11

First: DC motors

Fig.2: DC motor section

DC motors have been used in industrial applications for years Coupled with a DC drive, DC motors provide very precise control DC motors can be used with conveyors, elevators, extruders, marine applications, material handling, paper, plastics, rubber, steel, and textile applications, automobile, aircraft, and portable electronics, in speed control applications.

Advantages of DC motors:  It is easy to control their speed in a wide range; their torque-speed characteristic has, historically, been easier to tailor than that of all AC motor categories.  Their reduced overall dimensions permit a considerable space saving which let the manufacturer of the machines or of plants not to be conditioned by the exaggerated dimensions of circular motors.

Disadvantages of DC motors 

Brush wear occurs, and it increases dramatically in low‐ pressure environment.



Sparks from the brushes may cause explosion if the environment contains explosive materials.



RF noise from the brushes may interfere with nearby TV sets, or electronic devices, Etc.



DC motors are also expensive relative to AC motors.

Thus all application of DC motors have employed a mechanical switch or commutator to turn the terminal current, which is constant or DC, into alternating current in the armature of the machine. Therefore, DC machines are also called commutating machines. All application of DC motors have employed a mechanical switch or commutator to turn the terminal current, which is constant or DC, into alternating current in the armature of the machine.

12

Types of DC motors:

The DC motors are divided to: 1. Brush DC motors (BDC). 2. Brushless DC motors (BLDC).

1 : Brush DC motors:

Fig.2: brushed DC motor A brushed DC motor (BDC) is an internally commutated electric motor designed to be run from a direct current power source. 13

Applications: 

Brushed DC motors are widely used in applications ranging from toys to push-button adjustable car seats.

Advantages: 

Brushed DC (BDC) motors are inexpensive, easy to drive, and are readily available in all sizes and shapes

Disadvantages: 

Brushes wear and create an eclectically conductive dust



Electrical noise (EMI & RFI Interference) from the brush commutator interface



Commutator wear



Cogs at low speed

Construction: 1. Stator The stator generates a stationary magnetic field that surrounds the rotor. This field is generated by either permanent magnets or electromagnetic winding.

2. Rotor The rotor is made up of one or more windings. When these windings are energized they produce a magnetic field. The magnetic poles of this rotor field will be attracted to the opposite poles generated by the stator, causing the rotor to turn. As the motor turns, the windings are constantly being energized in a different sequence so that the magnetic poles generated by the rotor do not

14

overrun the poles generated in the stator. This switching of the field in the rotor windings is called commutation.

3. Brushes and Commutator: The commutation of the windings of a BDC motor is done mechanically. A segmented copper sleeve, called a commutator, resides on the axle of a BDC motor. As the motor turns, carbon brushes (ride on the side of the commutator to provide supply voltage to the motor) slide over the commutator, coming in contact with different segments of the commutator.

Types of BDC motors: The different types of BDC motors are distinguished by the construction of the stator or the way the electromagnetic windings are connected to the power source. These types are: 1. Permanent Magnet 2. Shunt-Wound 3. Series-Wound 4. Compound-Wound 5. Separately excited DC motor 6. Universal Motor 15

7. Servo Motors

1-Permanent Magnet: A permanent magnet DC (PMDC) motor is a motor whose poles are made out of permanent magnets to produce the stator field.

Advantages: 

Since no external field circuit is needed, there are no field circuit copper losses.



Since no field windings are needed, these motors can be considerable smaller .



Widely used in low power application.



Field winding is replaced by a permanent magnet (simple construction and less space).



No requirement on external excitation

Disadvantages: 

Since permanent magnets produces weaker flux densities then externally supported shunt fields, such motors have lower induced torque .



There is always a risk of demagnetization from extensive heating or from armature reaction effects (Some PMDC motors have windings built into them to prevent this from happening).

2- Shunt-Wound: Shunt-wound Brushed DC (SHWDC) motors have the field coil in parallel (shunt) with the armature . The speed is practically constant independent of the load and therefore suitable for commercial applications with a low starting load, such as centrifugal pump, machine tools, blowers fans, reciprocating pumps, etc

16

Advantages: 1. The current in the field coil and the armature are independent of one another. As a result, these motors have excellent speed control 2. Loss of magnetism is not an issue in SHWDC motors so they are generally more robust than PMDC motors 3. Speed can be controlled by either inserting a resistance in series with the armature (decreasing speed) or by inserting resistance in the field current (increasing speed)

Disadvantages: 1. It has drawbacks in reversing applications, however, because winding direction relative to the shunt winding must be reversed when armature voltage is reversed. Here, reversing contactors must be used

3- Series-Wound: These motors are ideally suited for high-torque applications such as traction vehicles (cranes and hoists, electric trains, conveyors, elevators, electric cars) because the current in both the stator and armature increases under load

Advantages: 

The torque is proportional to I2 so it gives the highest torque per current ratio over all other DC motors. 17

Disadvantages: 

A drawback to SWDC motors is that they do not have precise speed control like PMDC and SHWDC motors have.



Speed is restricted to 5000 RPM.



It must be avoided to run a series motor with no load because the motor will accelerate uncontrollably.

4- Compound-Wound: Compound Wound (CWDC) motors are a combination of shunt-wound and series-wound motors. CWDC motors employ both a series and a shunt field. The performance of a CWDC motor is a combination of SWDC and SHWDC motors. CWDC motors have higher torque than a SHWDC motor while offering better speed control than SWDC motor. It is used in Applications such as Rolling mills, sudden temporary loads, heavy machine tools, punches, etc. :

Advantages: 

This motor has a good starting torque and a stable speed.

Disadvantages: 

The no-load speed is controllable unlike in series motors.

5- Separately excited DC motor: In a separately excited DC motor the field coils are supplied from an independent source, such as a motor-generator and the field current is unaffected by changes in the armature current. The

18

separately excited DC motor was sometimes used in DC traction motors to facilitate control of wheel slip.

Advantages: 

Cost savings.



Additional cost savings from using a single DC controller instead of two AC controllers;



Elimination of the steering and motor-speed sensors;



Lower DC motor cost;



Simplified and less expensive wiring; and



Better performance.

6- Universal Motor: The universal motor is a rotating electrical machine similar to DC series motor, designed to operate either from AD or DC source. The stator & rotor windings of the motor are connected in series through the rotor commutator. The series motor is designed to move large loads with high torque in applications such as crane motor or lift hoist.

Advantages: 19



Small size, operates at 7,500 to 10,000 rpm



Lighter weight per HP rating



Can operate on AC or DC



Ideal for hand held tools



Ideal for home appliances like vacuum cleaners



Low cost



High starting torque

Disadvantages: 

Operates at 7,500 to 10,000 rpm



Requires gearing to reduce the output speed but gains output torque (adds to the audible noise)



Brushes, less reliable



Noisy



Unidirectional



Poor speed regulation

7- Servo Motors: Servo Motors are mechanical devices that can be instructed to move the output shaft attached to a servo wheel or arm to a specified position. Servo Motors are designed for applications involving position control, velocity control and torque control. A servo motor mainly consists of a DC motor, gear system, a position sensor which is mostly a potentiometer, and control electronics

.

Advantages: 

Intermediate motor and control costs



Continuous duty 20



Reversible.



Speed is proportional to the applied voltage



Torque is proportional to the current



Very efficient



No power required to hold a static load in position



Flat speed-torque curve



Peak torque available for short periods of time



Smooth rotation at low speeds



Good up to 3,000 RPM

Disadvantages: 

Brushes wear and create an eclectically conductive dust



Electrical noise (EMI & RFI Interference) from the brush commutator interface



Commutator wear



Position is limited to the feedback resolution (2000 line encoder produces 8000 steps per revolution



Poor thermal performance. Current/heat is in the rotor.



Requires tuning

Second- AC Motors:

The basic parts for AC motors are as follows: 1. Enclosure. 2. Stator. 3. Rotor. 4. Bearings. 21

5. Conduit Box. 6. Eye Bolt.

1- Enclosure:

The enclosure consists of a frame (or yoke) and two end brackets (or bearing housings). A motor's enclosure not only holds the motor's components together, it also protects the internal components from moisture and containments. The degree of protection depends on the enclosure type. In addition, the type of enclosure affects the motor's cooling.

2- Stator:

The motor stator consists of two main parts:

A- Stator Core : The stator is the stationary part of the motor's electromagnetic circuit. The stator is electrical circuit that performs as electromagnet. The stator core is made up of many thin metal sheets, called laminations.

B- Stator (Windings) 22

Stator laminations are stacked together forming a hollow cylinder. Coils of insulated wire are inserted into slots of the stator core.

3- Rotor:

The rotor is the rotating part of the motor's electromagnetic circuit. Magnetic field from the stator induces an opposing magnetic field onto the rotor causing the rotor to “push” away from the stator field. There are a lot of rotor types like Squirrel cage rotor and wound rotor.

4- Bearings: Bearings, mounted on the shaft, support the rotor and allow it to turn. Not all bearings are suitable for every application; a universal, all-purpose bearing does not exist.

The size of the bearing to be used is initially selected on the basis of its load carrying capacity, in relation to the load to be carried, and the requirements regarding its life and reliability.

Types of AC motors: An AC motor is an electric motor driven by an alternating current (AC). 23

It commonly consists of two basic parts, an outside stationary stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft that is given a torque by the rotating field. There are two main types of AC motors, depending on the type of rotor used. The first type is the induction motor or asynchronous motor; First-Induction motor: Three Phase Induction Motor: The three phase ac induction motor is also called a squirrel cage motor. Both single phase and three phase motors operate on the principle of a rotating magnetic field. A horseshoe magnet held over a compass needle is a simple illustration of the principle of the rotating field.

Advantages: 

High starting and running torque



Relatively constant speed



Fast acceleration



Brushless, more reliable



Economical



Size ranges from about 1/10 to about 10 HP

Disadvantages: 

Can’t be used with a speed control



Low start and stop rate



High starting current



Prolonged starting time can cause over heating



Has a mechanical centrifugal switch

Second-Synchronous Motor: The synchronous motor makes use of a rotating magnetic field. Unlike the induction motor, however, the torque developed does not depend on the induction of currents in the rotor. Briefly, the principle of operation of the synchronous motor is as follows: A multiphase source of ac is applied to the stator windings, and a rotating magnetic field is produced. 24

A direct current is applied to the rotor winding, and another magnetic field is produced.

Advantages: 

Operates at an exact, constant speed



Brushless, more reliable

Disadvantages: 

Low starting torque



Starting the load inertia must be within the motor’s capability.

Speed Control of DC Motor: Speed control means intentional change of the drive speed to a value required for performing the specific work process. Speed control is a different concept from speed regulation where there is natural change in speed due change in load on the shaft. Speed of the DC machine can be controlled by: 1. By applying the voltage to the terminals of the dc machine 2. By introducing external resistance in the armature of the machine 3. By varying the flux per pole (φ) of the machine

Speed Control of DC Series Motor: Speed control of DC series motor can be done either by armature control or by field control. First: Armature Control of DC Series Motor: Speed adjustment of DC series motor by armature control may be done by any one of the methods that follow, 25

i)

Armature Resistance Control Method: In armature resistance control method a variable resistance is connected in series to the armature circuit. When the resistance of the rheostat is increased, current flowing through the circuit reduces and the voltage drop at the armature is less compared to line voltage. Thus speed of the machine reduces in proportional to the applied voltage.

ii)

Shunt Resistance Control Method: In this method the change in the armature current (because of the load torque) does not affect the change in the voltage across the terminals hence the speed.

iii)

Armature Voltage Control: In this method of speed control a variable source of voltage is provided to supply the power to the armature circuit. Voltage to the field circuit should be different from the variable voltage source provided to the armature.

Second: Field Control Method of speed control: The speed can be controlled by: 

Providing a variable resistance in series to the field circuit so that variation in the resistance value results in increase or decrease in the field of the machine resulting in the speed control.



By variation in the reluctance of the magnetic circuit of the motor.



By varying the applied voltage to the field circuit of the DC motor by keeping the voltage supplied to the armature circuit constant.

i) Field Resistance Control: In this method variable resistance is employed in series to the field circuit. As in this method when resistance value increases only field weakens. By weakening the field speed above the normal speed can be attained. ii) Reluctance Control Method: This method requires motor to be constructed with special mechanical features such that reluctance of the magnetic circuit can be changed. This is more expensive and rarely employed. iii) Filed Voltage Control: This method requires variable voltage source which is different from the voltage applied to the armature circuit.

26

Chapter 3

CONTROL OF THE ELECTRICAL MACHINES

27

CONTROL OF THE ELECTRICAL MACHINES 1. Introducton A typical electric drive system includes a controller, a transmission, an electric motor and a driven load (e.g., fans, pumps, conveyors and others previously cited.) A key difference in different types of electric drive systems is the type of controller: (A) distinct DC motor control components, such as motor starters, switches and operator controls, or (B) electronic motor controllers, called drive controls, which use semiconductors with electronic circuitry and software to perform the same functions of distinct DC motor control components.

2. Types of DC Motor Control There are three general types of DC motor control: manual, semi-automatic and automatic. Manual control directly connects a DC motor to the input power line or mains. Operator intervention is required. Semi-automatic control uses switches or sensors (.e.g., limit, pressure, temperature, float level, flow, proximity, timing and photo-sensitive switches) to control a magnetic contactor or starter which, when enabled or closed, will connect the motor to the input power line. In semi-automatic operation, an operator is needed to start or stop the motor but the rest of the operation is controlled by the sensors or switches. Automatic control is similar to semi-automatic control with one important difference: no operator intervention is required. For example, a thermostat in an air conditioning system or a refrigerator will turn a compressor motor on or off to maintain the set point temperature automatically.

3. Functions of DC Motor Control Whether a DC motor is controlled manually, semi-automatically or automatically, the control system will perform a variety of common functions, which include: 

Starting



Stopping



Jogging/Inching



Plugging



Speed Control



Reversing



Braking



Protection

28

4. Advantages of DC Motors 

Ease of control



Deliver high starting torque



Near-linear performance

5. Disadvantages of DC Motors 

High maintenance



Large and expensive (compared to induction motor)



Not suitable for high-speed operation due to commutator and brushes

 Not suitable in explosive or very clean environment An applications of DC Motors doesn't indicate the use only, it means why and where we use a DC Motor. As we all know DC Motors are of three types: Shunt Motors Series Motors Compound Motors I will not go in deep about the classification. For those who are not aware about the classification I would like to tell why this name is given ? The name for a DC Motor is given on the bases of connection between armature and field coil. If field coil or field winding is connected in parallel with the armature then the motor is called shunt motor, if connection is series the motor is called series motor and if two field windings are used one is series and one in shunt then the motor is called compound motor.

6. Applications of DC Motors Now I will discuss application criteria for all three types of DC Motors. 6.1. Shunt Motors There are three kind of characteristics for a motor viz. Speed-Torque, Speed-Current and Torque-Current characteristics. After analyzing all three characteristics for DC Shunt Motor it is observed that it is an approximately constant speed motor. It is therefore, used where the speed is required to remain almost constant from no-load condition to full load-condition. The load has to be driven at a number of prefer and any one of which is required to remain nearly constant. Industrial Use: - Lathes, Drills, Boring Mills, Shapers, Spinning and Weaving Machines etc.

29

6.2. Series Motors After analyzing all three characteristics for DC Series Motor it is observed that it is a variable speed motor. It means speed it low at high torque and vice-versa. However, at light or no-load, the motor tends to attain dangerously high speed. The motor has a high starting torque. It is therefore, used where Large starting torque is required like in Elevators and Electric Traction. The load is subjected to heavy fluctuations and the speed is automatically required on sewing machines etc. Industrial Use : - Electric traction, brands, elevators, air compressors, vacuum cleaners, hair drier, sewing machines etc.

6.3. Compound Motors DC Compound Motor is of two types. It is therefore, used where, specification required for particular motor. Differential-compound motors are rarely used because of their poor torque characteristics. Cumulative-compound motors are used where a fairly constant speed is required with irregular loads or suddenly applied heavy load.

7. Introduction to Electronic DC Drives An electronic DC drive, sometimes called a semi-conductor drive, is a subset of all the various electric drive systems used to control the motion and vary the speed of a DC motor. Early electric drive types, such as the Ward-Leonard system, controlled the motors indirectly. The Ward-Leonard system is an AC motor-DC generator set that feeds a variable voltage to the armature of a shunt wound DC motor to vary the motor’s speed. While the Ward-Leonard system has good speed and torque control with a speed range of 25:1, it was phased out due to the excessive cost of purchasing three separate rotating machines as well as the considerable maintenance necessary to keep the brushes and commutators of two DC machines in proper operating conditions. (A similar fate happened to the eddy current clutch. ) Today’s electronic DC drives have numerous advantages over previous electrical drive systems, such as the Ward-Leonard drive. They include: 

Large range of power availability.



Capable of full torque at standstill without a clutch.



Very large speed range without needing gearboxes.



Clean operation.



Safe operation in hazardous environments.



Immediate use (no warm up time)



Low no-load losses. 30



Low acoustic noise.



Excellent control ability.



Four-quadrant operation: forward motoring, forward braking, reverse motoring and reverse braking . While the advantages are numerous, electronic DC drives have some disadvantages, such as: Very complex and require highly skilled technicians to maintain. Introduce harmonics/electrical noise into the power line

8. Electronic DC Drives: Control Methodology and Characteristics An electronic DC drive is an electronic thyristor AC/DC converter/rectifier or a DC/DC converter, called a DC chopper. A converter is a complex electronic control that can precisely control a DC motor’s rotation, torque and speed characteristics. AC/DC converters come in several configurations: (A) full-wave, 12-pulse bridge, (B) full-wave, 6-pulse bridge, or (C) half-wave, 3-pulse bridge. The most common configuration is the full-wave, 6-pulse bridge because it produces less distortion on the DC side of the converter and has lower losses in the DC motor than a 3-pulse bridge. (12-pulse bridges are typically used on larger drives to reduce harmonics on the AC power line.) The efficiency of the converter is usually greater than 98% and the overall efficiency of the DC drive plus the DC motor is about 90%. In addition, AC/DC converters can be built for applications up to several megawatts with good control and performance characteristics.

The other type of DC drive controller is a DC-to-DC converter or a DC chopper. While an AC/DC converter is powered from an A.C. supply, the DC chopper is powered from a DC power source. Both electronic controls produce a variable DC voltage that when applied to the DC motor’s armature varies the armature current, hence, the motor speed. The AC/DC converter produces this variable DC voltage by controlling the firing angle of its SCR bridge rectifier, while a DC chopper varies the voltage by controlling the varying angle to vary the duty cycle. The output voltage of the chopper is in the form of pulses. The time ratio of the chopper can be controlled to vary the average voltage. Voltage variation at the load can be obtained by either current limit or time ratio control. For instance, in current-limit control, when current reaches the upper limit, the chopper is turned off to disconnect the motor from supply. Load current freewheels through the freewheeling diode and decays. When it falls to the lower limit, the chopper is turned on and connected to supply, thus, an average current is maintained.

31

CHAPTER 4

Convertor

32

CONVERTERS Introduction: There are two basic types of converters, digital-to-analog and analog-to digital. Their purpose is fairly straightforward. In the case of DACs ,they output an analog voltage that is a proportion of a reference voltage, the proportion based on the digital word applied. In the case of the ADC, a digital representation of the analog voltage that is applied to the ADCs input is outputted, the representation proportional to a reference voltage.

First: DIGITAL-TO-ANALOG CONVERTER:

A digital-to-analog converter (DAC or D-to-A) is a device that converts a digital (usually binary) code to an analog signal (current, voltage, or electric charge). An analog-to-digital converter (ADC) performs the reverse operation. Signals are easily stored and transmitted in digital form, but a DAC is needed for the signal to be recognized by human senses or other nondigital systems.

Operation: Instead of impulses, usually the sequence of numbers update the analog voltage at uniform sampling intervals which are often then interpolated via a reconstruction filter to continuously varied levels. These numbers are written to the DAC, typically with a clock signal that causes each number to be latched in sequence, at which time the DAC output voltage changes rapidly from the previous value to the value represented by the currently latched number. The effect of this is that the output voltage is held in time at the current value until the next input number is latched resulting in a piecewise constant or 'staircase' shaped output. This is equivalent to a zero-order hold operation and has an effect on the frequency response of the reconstructed signal. 33

Piecewise constant output of an idealized DAC lacking a reconstruction filter.

Applications: 1. Audio: Most modern audio signals are stored in digital form (for example MP3s and CDs) and in order to be heard through speakers they must be converted into an analog signal.

A simplified functional diagram of an 8-bit DAC 2. Video: Video sampling tends to work on a completely different scale altogether thanks to the highly nonlinear response both of cathode ray tubes (for which the vast majority of digital video foundation work was targeted) and the human eye, using a "gamma curve" to provide an appearance of evenly distributed brightness steps across the display's full dynamic range.

Top-loading CD player and external digital-to-analog converter.

DAC types: There are many types of DAC, like: 

The pulse-width modulator, the simplest DAC type.



Oversampling DACs or interpolating DACs.



The binary-weighted DAC.

34

Pulse-width modulation (PWM): PWM Is a modulation technique that conforms the width of the pulse, formally the pulse duration, based on modulator signal information. Although this modulation technique can be used to encode information for transmission, its main use is to allow the control of the power supplied to electrical devices, especially to inertial loads such as motors. In addition, PWM is one of the two principal algorithms used in photovoltaic solar battery chargers.

PWM in an AC motor drive. The average value of voltage (and current) fed to the load is controlled by turning the switch between supply and load on and off at a fast pace. The longer the switch is on compared to the off periods, the higher the power supplied to the load is.

Applications: 1) Telecommunications: In telecommunications, PWM is a form of signal modulation where the widths of the pulses correspond to specific data values encoded at one end and decoded at the other. Pulses of various lengths (the information itself) will be sent at regular intervals (the carrier frequency of the modulation). 2) Power delivery: PWM can be used to control the amount of power delivered to a load without incurring the losses that would result from linear power delivery by resistive means. Potential drawbacks to this technique are the pulsations defined by the duty cycle, switching frequency and properties of the load. With a sufficiently high switching frequency and, when necessary, using additional passive electronic filters, the pulse train can be smoothed and average analog waveform recovered. 3) Voltage regulation: PWM is also used in efficient voltage regulators. By switching voltage to the load with the appropriate duty cycle, the output will approximate a voltage at the desired level. The switching noise is usually filtered with an inductor and a capacitor. 4) Audio effects and amplification: 35

PWM is sometimes used in sound synthesis, in particular subtractive synthesis, as it gives a sound effect similar to chorus or slightly detuned oscillators played together. (In fact, PWM is equivalent to the difference of two sawtooth waves with one of them inverted.

Second: ANALOG-TO-DIGITAL CONVERTER: An analog-to-digital converter is a device that converts a continuous physical quantity (usually voltage) to a digital number that represents the quantity's amplitude. The conversion involves quantization of the input, so it necessarily introduces a small amount of error. Instead of doing a single conversion, an ADC often performs the conversions ("samples" the input) periodically. The result is a sequence of digital values that have converted a continuous-time and continuous-amplitude analog signal to a discrete-time and discreteamplitude digital signal.

Photo of the ADC-16 Analog to Digital converter

ADC types: 1. Direct-conversion ADC or flash ADC. 2. Successive-approximation ADC. 3. Ramp-compare ADC. 4. The Wilkinson ADC. 5. An integrating ADC. 6. A time-stretch analog-to-digital converter (TS-ADC).

Applications: 1) Digital signal processing: People must use ADCs to process, store, or transport virtually any analog signal in digital form. TV tuner cards, for example, use fast video analog-to-digital converters. Slow on-chip 8, 10, 12, or 16 bit analog-to-digital converters are common in

36

microcontrollers. Digital storage oscilloscopes need very fast analog-to-digital converters, also crucial for software defined radio and their new applications. 2) Scientific instruments: Digital imaging systems commonly use analog-to-digital converters in digitizing pixels. Some radar systems commonly use analog-to-digital converters to convert signal strength to digital values for subsequent signal processing. Many other in situ and remote sensing systems commonly use analogous technology. The number of binary bits in the resulting digitized numeric values reflects the resolution, the number of unique discrete levels of quantization (signal processing).

DC to DC Converter: This is a type of converter. DC-DC converters are electronic devices used to change DC electrical power efficiently from one voltage level to another. They are needed because unlike AC, DC cannot simply be stepped up or down using a transformer. In many ways, a DC-DC converter is the DC equivalent of a transformer.

DC/DC Converter DC12V to 24V 2A by IC 40106 and Mosfet BUZ11

Applications: DC to DC converters are important in portable electronic devices such as cellular phones and laptop computers, which are supplied with power from batteries primarily. Such electronic devices often contain several sub-circuits, each with its own voltage level requirement different from that supplied by the battery or an external supply (sometimes higher or lower than the supply voltage).

37

Conversion methods: 

Electronic: Linear regulators can only output at lower voltages from the input. They are very inefficient when the voltage drop is large and the current is high as they dissipate heat equal to the product of the output current and the voltage drop; consequently they are not normally used for large-drop high-current applications.

A linear 5V regulator IC Linear regulators are practical if the current is low, the power dissipated being small, although it may still be a large fraction of the total power consumed. They are often used as part of a simple regulated power supply for higher currents. 

Switched-mode conversion: It converts one DC voltage level to another, by storing the input energy temporarily and then releasing that energy to the output at a different voltage.

Switched-mode power supply 

Magnetic: In these DC-to-DC converters, energy is periodically stored into and released from a magnetic field in an inductor or a transformer, typically in the range from 300 kHz to 10 MHz. By adjusting the duty cycle of the charging voltage the amount of power transferred can be controlled.

38

Types of DC to DC Converter: 1. Linear Voltage Converters: The most elementary DC-DC converters are linear voltage converters. They achieve DCDC voltage conversion by dissipating the excess power into a resistor, making them resistive dividers. The advantage of linear voltage converters is that they are fairly simple to implement. Moreover, they generally do not need large, and space consuming, inductors or capacitors, making them an attractive option for monolithic integration.

(a) The principle of a linear series voltage converter and (b) a simple practical implementation

2. Buck Converters: A buck converter (DC-DC) is a switch for which a device as described earlier belonging to transistor family is used. Also a diode (termed as free wheeling) is used to allow the load current to flow through it, when the switch (i.e., a device) is turned off. The load is inductive (R-L) one. In some cases, a battery (or back emf) is connected in series with the load (inductive). Due to the load inductance, the load current must be allowed a path, which is provided by the diode; otherwise, i.e., in the absence of the above diode, the high induced emf of the inductance, as the load current tends to decrease, may cause damage to the switching device.

Buck converter (DC-DC)

39

Output voltage and current waveforms 3. Boost Converters (DC-DC): The operation of the circuit is explained. Firstly, the switch, S (i.e., the device) is put ON (or turned ON) during the period, the ON period being . The output voltage is zero , if no battery (back emf) is connected in series with the load, and also as stated earlier, the load inductance is small. The current from the source (is ) flows in the inductance L.

Boost converter (dc-dc)

Waveforms of source current 4. Current Limit Control: the current changes between the maximum and minimum values, if it (current) is continuous. In the current limit control strategy, the switch in DC-DC converter (chopper) is turned ON and OFF, so that the current is maintained between two (upper and lower) limits.

40

Current limit control

Basic Types of Inverters: There are different types of inverters for home available which can suit your various electricity needs. The availability of inverter service centers also make it easy for you to get them fixed. Following are the two basic types of inverters.

1. Modified Sine Wave Inverters: This type of home inverter obtains power from a battery of 12 volts and must be recharged using a generator or a solar panel. Appliances like microwave ovens, light bulbs, etc. can be run using these types of inverter.



They can be rightly held as the best inverters for homes as they are efficient enough to provide power to the normal home requirement.



They are the home inverters that are most affordable too.



You can run the daily used home appliances using the modified sine wave home inverters.



The electric appliances that involve motor speed controls or timers are not to be run using these types of home inverters.

41

2. True Sine Wave Inverters: This is one of the better types of inverters as they provide better power as compared to the modified sine wave inverters for homes. These types of home inverter are also run using a battery of a larger capacity.



Technically speaking, the sine waves they produce are purer, thus the efficiency.



They are best inverters employed for the power sensitive appliances like refrigerators, televisions, air conditioners, washing machines, etc.



These types of inverters are extremely reliable. The only drawback is that they are a bit expensive and cannot be afforded by the common man.



There are various models available based on the electricity requirement of the house.

3. Solar Inverters: A solar inverter, or PV inverter, converts the variable direct current (DC) output of a photovoltaic (PV) solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-grid electrical network. It is a critical component in a photovoltaic system, allowing the use of ordinary commercial appliances.

Some basic types of solar inverters are: 

Stand-alone inverters: Stand-alone inverter or off-grid inverter is designed for remote stand-alone application or off-grid power system with battery backup where the inverter draws its DC power from batteries charged by PV array and converts to AC power. 42



Grid connected inverter: Grid connected inverter or grid tie inverter is designed specifically for grid connected application that does not require battery backup system. Grid connected inverter or grid tie inverter converts DC power produced by PV array to AC power to supply to electrical appliances and sell excess power back to utility grid.



Hybrid inverter: Hybrid inverter or hybrid power inverter is designed for hybrid power system that combines solar array with diesel generator and other renewable energy sources such as wind turbine generator, hydro generator, etc. Hybrid inverter can operate as either a stand-alone inverter or a grid tie inverter.

4. Power inverter: A power inverter, or inverter, is an electrical power converter that changes direct current (DC) to alternating current (AC). The input voltage, output voltage, and frequency are dependent on design. 

Applications: 1. DC power source utilization: An inverter converts the DC electricity from sources such as batteries, solar panels, or fuel cells to AC electricity. The electricity can be at any required voltage; in particular it can operate AC equipment designed for mains operation, or rectified to produce DC at any desired voltage. 2. Uninterruptible power supplies: An uninterruptible power supply (UPS) uses batteries and an inverter to supply AC power when main power is not available. When main power is restored, a rectifier supplies DC power to recharge the batteries. 3. Induction heating: Inverters convert low frequency main AC power to higher frequency for use in induction heating. To do this, AC power is first rectified to provide DC power. The inverter then changes the DC power to high frequency AC power. 4. HVDC power transmission: With HVDC power transmission, AC power is rectified and high voltage DC power is transmitted to another location. At the receiving location, an inverter in a static inverter plant converts the power back to AC. The inverter must be synchronized with grid frequency and phase and minimize harmonic generation.

5. Variable-frequency drives: 43

A variable-frequency drive controls the operating speed of an AC motor by controlling the frequency and voltage of the power supplied to the motor. An inverter provides the controlled power. In most cases, the variable-frequency drive includes a rectifier so that DC power for the inverter can be provided from main AC power. 6. Electric vehicle drives: Adjustable speed motor control inverters are currently used to power the traction motors in some electric and diesel-electric rail vehicles. 7. Air conditioning: An inverter air conditioner uses a variable-frequency drive to control the speed of the motor and thus the compressor. 

Circuit description:

In one simple inverter circuit, DC power is connected to a transformer through the center tap of the primary winding. A switch is rapidly switched back and forth to allow current to flow back to the DC source following two alternate paths through one end of the primary winding and then the other. The alternation of the direction of current in the primary winding of the transformer produces alternating current (AC) in the secondary circuit. Output waveforms:

44

When not coupled to an output transformer, produces a square voltage waveform due to its simple off and on nature as opposed to the sinusoidal waveform that is the usual waveform of an AC power supply. Using Fourier analysis, periodic waveforms are represented as the sum of an infinite series of sine waves. The sine wave that has the same frequency as the original waveform is called the fundamental component. The other sine waves, called harmonics, that are included in the series have frequencies that are integral multiples of the fundamental frequency.

5. Controlled rectifier inverters: The thyristor or silicon-controlled rectifier (SCR) that initiated the transition to solid state inverter circuits. The commutation requirements of SCRs are a key consideration in SCR circuit designs. SCRs do not turn off or commutate automatically when the gate control signal is shut off. They only turn off when the forward current is reduced to below the minimum holding current, which varies with each kind of SCR, through some external process. For SCRs connected to an AC power source, commutation occurs naturally every time the polarity of the source voltage reverses. SCRs connected to a DC power source usually require a means of forced commutation that forces the current to zero when commutation is required.

45

The least complicated SCR circuits employ natural commutation rather than forced commutation. With the addition of forced commutation circuits, SCRs have been used in the types of inverter circuits described above. In applications where inverters transfer power from a DC power source to an AC power source, it is possible to use AC-to-DC controlled rectifier circuits operating in the inversion mode. In the inversion mode, a controlled rectifier circuit operates as a line commutated inverter. This type of operation can be used in HVDC power transmission systems and in regenerative braking operation of motor control systems.

46

CHAPTER 5 SIMULATION FOR DC MOTOR SYSTEM DRIVE BY USING P.W.M CONVERTER

47

SIMULATION FOR DC MOTOR SYSTEM DRIVE BY USING P.W.M CONVERTER 1. Introduction Residential application needs single phase AC power, with a fixed frequency only. The inverter is constant frequency 60Hz and voltage depends on the converter. Static inverters may be classified into one of the following categories, on the basis of the type of AC output. 1. Voltage source inverters 2. Current source inverters This converter is used to drive for DC motor.

2. Converter Simulation by Using Matlab Simulink 2.1. Fixed Frequency Voltage Source Inverters This is the most commonly used type of inverter. The AC that it provides on the output side functions as a voltage source. The input is from a DC voltage source. The input DC voltage may be from the rectified output of an AC power supply, in which case it is called a "DC link" inverter. Alternatively, the input DC may be from an independent source such as a battery.

2.2. Fixed Fundamental Output Voltage and Frequency The full bridge has four "switching blocks" each consisting of a controlled switch and its ant parallel diode. If, it is the case with an inductive load, the load current does not immediately reverse, and then once commutation is complete, Sa will cease to conduct with the load current being transferred to diode D4. The types of full bridge can be operated with and without PWM are illustrated in the following steps: 1. Square wave operation fixed fundamental output voltage. 2. Sinusoidal PWM with different carrier frequency and modulation index.

3. Simulation of DC-DC Converter A Simulink model of this system is designed to examine its performance as shown in Fig.4.1. The converter model is referred described voltage. The converter output which has constant frequency at 60Hz depending on PWM of the control circuit. The simulation study is performed with PWM.

48

3.1. Simulation Results With PWM Converter A Simulink model of this system is designed to examine its performance as shown in Fig.4.1. The DC-DC converter is simulated by sine wave and triangle wave control. The sine wave, triangle wave and the resulting square wave pulse are shown in Fig.4.2. The control output voltage is shown in Fig.4.3.

Fig 4.1: Three & Single phase and DC converter simulink model of the P.W.M.

49

1.5

1

sine and triangle waves

0.5

0

-0.5

-1

-1.5 1.345

1.35

1.355

1.36

1.365 Time (second)

1.37

1.375

1.366 Time (second)

1.368

1.37

1.38

1.385

1.5

1

sine and triangle waves

0.5

0

-0.5

-1

-1.5 1.358

1.36

1.362

1.364

1.372

1.374

Fig.4.2: Sine wave and triangle waves.

1.5

output pulses

1

0.5

0 1.271

1.272

1.273

1.274 Time (second)

1.275

1.276

Fig.4.3: DC output pulses of PWM converter. 50

1.277

4. Simulation of AC Inverter A simulink model of this system is designed to examine its performance as shown in Fig.4.1. The three phase and single phase inverter control is simulated by sin wave and triangle wave control. The AC output voltage equations for PWM inverter is illustrated in the following VA = Va puls -- Vb puls -- Vc puls

(1)

VB = Vb puls -- Va puls -- Vc puls

(2)

VC = Vc puls -- Va puls -- Vb puls

(3)

4.1. Simulation Results of Single-Phase and Three-Phase Inverter The three phase sine wave and triangle wave are shown in Fig.4.4. The single-phase output voltage of PWM as shown in Fig.4.5. The three-phase output voltage of PWM as shown in . Fig.4.6. 1.5

three phase sine and triangle waves

1

0.5

0

-0.5

-1

-1.5 1.175

1.18

1.185

1.19

1.195 Time (second)

1.2

1.205

1.21

1.5

three phase sine and triangle waves

1

0.5

0

-0.5

-1

-1.5 1.184

1.186

1.188

1.19

1.192

1.194 Time (second)

1.196

1.198

Fig.4.4: Three sine and triangle waves. 51

1.2

1.202

1.204

3

2

single phase voltage

1

0

-1

-2

Fig.4.5: Single phase output voltage of inverter.

-3 1.48

1.49

1.5

1.51 Time (second)

1.52

1.53

1.54

8

6

three phase voltage

4

2

0

-2

-4

-6

-8

1.05

1.1

1.15

1.2

1.25

1.3

Time (second)

Fig.4.6: Three phase (A,B*2,C*3) output voltage of inverter.

5. Simulation of DC Motor is supplied by DC - DC Converter 5.1. DC Permanent Magnet Motor Construction The permanent magnet DC machines are widely found in a wide variety of low power applications. The field winding is replaced by a permanent magnet, resulting in simpler construction. Permanent magnets offer a number of useful benefits in these applications. The space required for the permanent magnets may be less than that required for the field winding and thus permanent- magnet machines may be smaller , and in some case cheaper , than their externally- excited counterparts. Alternatively, permanent magnet DC machines are subjected to limitations imposed by the permanent magnets themselves. These include the risk of demagnetization due to excessive currents in the motor windings or due to overheating of the magnet. In addition, permanent magnets are somewhat limited in the magnitude of air gap flux density that they can produce. However, with the development of new magnetic materials such as samarium-cobalt and 52

neodymium-iron-boron, these characteristics are becoming less are less restrictive for permanent-magnet machine design. The proposed system can be simulated with proper mathematic modeling. The permanent magnet DC motor can be written in terms of equations as follows and. The non linear model equations can be simulated using Matlab/Simulink in overall system Fig 4.7. : dia (t ) V (t ) R K  t  a ia (t )  v  r (t ) dt La La La

(4)

K d r (t ) T f  v ia (t )   r (t )  L dt J J J

(5)

where ,

i a = The motor current,

Vt = The motor terminal voltage,

Ra, La = The armature resistance and inductance,

ωr = The motor angular speed,

J

= The moment of inertia,

TL = The load torque,

f

= The friction coefficient,

Kv = The field constant.

Fig.4.7: Simulink model of the DC motor. 53

5.2. Simulation Results for DC Motor is Supplied by Constant Voltage Figure 4.8. is illustrated the motor current and figure 4.9. is illustrated the motor actual speed

35

30

motor current

25

20

15

10

5

0.1

0.2

0.3

0.4 Time (second)

0.5

0.6

0.7

0.8

Fig.4.8: The motor current.

motor speed (rpm)

1500

1000

500

0

0

0.2

0.4

0.6

0.8 Time (second)

Fig.4.9: The motor speed.

54

1

1.2

5.3. Simulation Model for DC Motor is Supplied by PWM Converter Fig.4.10. is illustrated the simulation model

.

Fig.4.10: Simulink model of the DC motor with converter. 5.3.1. Simulation Results for DC Motor is Supplied by Output Pulses for Converter Fig.4.11. is illustrated the motor current and Fig.4.12. is illustrated the motor actual speed

30

motor current

25

20

15

10

5

0 0.05

0.1

0.15

0.2 Time (second)

0.25

Fig.4.11: The motor current.

55

0.3

0.35

0.4

1200

1000

motor speed (rpm)

800

600

400

Fig.4.12: The motor speed. 200

5.3.2 Simulation Results for DC Motor is Supplied by Output Average Voltage for Converter 0

0

0.05

0.1

0.15

0.2

0.25 Time (second)

0.3

0.35

0.4

0.45

Fig.4.13. is illustrated the motor current and Fig.4.14. is illustrated the motor actual speed 30

25

motor current

20

15

10

5

0

0

0.1

0.2

0.3

0.4

0.5 Time (second)

0.6

0.7

0.8

0.9

1

Fig.4.13: The motor current. 1200

1000

motor speed (rpm)

800

600

400

200

0

-200

0

0.1

0.2

0.3

0.4

0.5 Time (second)

0.6

Fig.4.14: The motor speed.

56

0.7

0.8

0.9

1

CHAPTER 6 PRACTICAL DESIGN, TESTING AND EXPERIMENTAL WORKS

57

PRACTICAL DESIGN, TESTING AND EXPERIMENTAL WORKS 1. Introduction The Practical and experimental system setup are designed, and tested as detailed in this chapter. The system consists of, four power supply (+12:0:-12, 0:+5, 0:+12 and 0:+15 volt) . Two signal generator circuits are build using two integrated circuits ICa 8038 and ICb 8038 which works as function generators ( to generate sine wave , triangle wave , and square wave signal ). Comparator circuit is used to compare the sine wave with Triangle wave (by used an operational amplifier circuit IC 741) and it give us the pulses, To get sharp output signal from the comparator the Schmitt trigger IC7414 circuit two stage inverter is used as demonstrated in Fig.5.2 . Also instead of using the function generator IC 8038 we can use the signal generator IC 2206 ( to generate sine wave, triangle wave, square wave, saw tooth signal, ramp signal, and pulse signals)

2. Drive Circuit of IGBT The drive circuit controls in duty cycle of converter to give the output ON and OFF of IGBT. Fig.5.1 shows the block diagram of the drive circuit to gate of IGBT

POWER +12

SUPPLY

+15

+5

TO (IGPT)

ISOLATING CIRCUITS (OPTOCOUPLER)(4N32) FUNCTION GENERATOR (ICa 8038) (SINWAVE) OPERATIONAL

SCHMITT TRIGGER

AMPLIFIERS (IC 741)

(IC 7414)

FUNCTION GENERATOR (ICb 8038) (Triangle)

Fig.5.1: The Block Diagram of Drive Circuit. 58

Fig.5.2 shows the schematic drive circuit to fire the IGBT, which is used as the switch S1 in converter. Fig.5.3 show the schematic circuit for the power supply. The details of drive circuit as illustrated in Fig.5.2 consists of : 

Two function generators are used. The 1st function generators (ICa 8038) is

adjusted to work at 20 kHz and the 2nd function generators (ICb 8038) work as variable frequency from 0 to 33KHz as illustrated in Figure 5.11a. 

Comparator IC LM741 is used to compare two signals together. The 1st one is

the triangular output wave from ICa 8038 (pin 3) and the 2nd one is the sine output wave from ICb 8038 (pin 2) as shown in Fig.5.12. 

The Schmitt trigger IC7414 circuit is used to get sharp output signal from the

comperator using two stage inverter. 

Optocoupler 4N32 is used to isolate the drive circuit from power circuit



Amplifier stage consists of two transistors to give ON and OFF signals to the gate

of IGBT.

59

5V R15=220Ω 7414

Vcc1

4N32

7414

R14=3.3kΩ R13=10kΩ

1 2

R12=10kΩ

3

+

5

g11

4

S11 GND1

7

2 -

6

R11=10kΩ ICa

VR4=20kΩ

R10=10kΩ

R9=10kΩ

8038

1

Sine wave ADJ

NC

14

2

Sine wave OUT

NC

13

3

Triangle OUT

Sine wave ADJ

12

4

DCF ADJ

V-OR GND

11

5

DCF ADJ

Timing CAP

10

6

+V

Square wave OUT

9

7

FM BIAS

FM Sweep INP

8

R6=91kΩ C2=0.0015 µf R5=100kΩ

R4=100kΩ VR2=20kΩ

C1=0.1 µf

ICb

8038

1

Sine wave ADJ

NC

14

2

Sine wave OUT

NC

13

3

Triangle OUT

Sine wave ADJ

12

4

DCF ADJ

V-OR GND

11

5

DCF ADJ

Timing CAP

10

6

+V

Square wave OUT

9

7

FM BIAS

FM Sweep INP

8

J1

+12 5 -12 4 +15 3 5

VR3=20kΩ

R8=10kΩ

2

0 1 CON5

R7=10kΩ

R3=91kΩ C2=0.0015 µf R2=100kΩ R1=100kΩ VR1=20kΩ

C1=0.1 µf

Fig 5.2: The Schematic diagram of electronic drive Circuit. 60

Fig 5.3: The Schematic Circuit diagram of DC Power Supply +5 , +12 , +15 , -12 , +12 DCV, 1A. 61

Now after this discussion of the details of the drive circuit given in Fig.5.2., the next step is used the flexible broad board in this project shown in Fig.5.4. This board is used only in the laboratory to build or rebuild, to design or redesign and test or retest the desired circuit.This means flexible connections of the desired circuit.

Fig 5.4: Flexible Broad Board After this idea on the flexible broad in Fig.5.4., the next step is used the hard coper board for permanent connections of the desired circuit. Now for the DC power supply circuit and the drive circuit, the model b is suatiable. Also for the AC transformer connections the model c is suatiable. After the selections of the suitable size and model of the copper board we start to colecte the different electrical component to build the final Graduation Project as the drive circuit control 62

for the machines. This is divided in 3 parts. The 1st one is AC transformer. Fig.5.7 a. illustrate the practical PIN diagram of AC power supply transformer, and Fig.5.7 b. demonstrate the coresponding schematic circuit terminals (Inputs 0- 110- 220V Outputs 0- 6- 9- 12- 15- 1824- 30 V 1 A)

Fig.5.7 a: The practical PIN diagram of power supply Transformer. (Inpts 0-110-220V Outputs 0- 6- 9- 12-15-18-24-30 V 1 A)

30 White 24 Green 220 Blue 18 Brown 110 Yellow YelGgR13=424

15 Yellow

N76 12 Orange 2R12=10kΩRVR 0 Black C1CNFM DCF 9 Red A11118764532IC 6 Blue R4=100kΩVRC1 CNFM DCF A11118764532IC 0 Black J1C54210 5 Fig.5.7 b: The Schematic circuit of power supply transformer Terminals R1=100kΩ +12

(Inpts 0-110-220V Outputs 0- 6- 9- 12-15-18-24-30 V 1 A) Now we start to build the drive circuit using Flexible broad of practical project electronic drive circuit as in Fig.5.8. 63

Fig.5.8. Flexible broad of practical project electronic drive circuit. After testing the flexible broad board of practical project electronic drive circuit, now start to draw the hard copper board of practical project electronic drive printed circuit as in Fig.5.9. 64

Fig.5.9 a: Drawing the hard copper board of AC power supply transformer

65

.

Fig.5.9 b: Drawing the hard copper board of Power Supply circuit .

66

Fig.5.9 c: Drawing the hard copper board of electronic drive circuit . 67

After finishing the drawing of the hard copper board of practical project electronic drive printed circuit, now start to build the hard copper board of practical project electronic drive printed circuits as shown in Fig.5.10.

Fig.5.10: Hard copper board of practical project electronic drive printed circuit 68

After finishing the flexible broad in Fig.5.8 and the hard copper board in Fig.5.10 of the drive circuit i.e the Graduation Project is finished from techanical point of view. Testing both circuits and getting all results and figures as follows :

At frequency f= 1.485 K Hz:

Fig.5.11 a: Ilustrate the triangular with DC voltge

1.5 1 0.5 0 -0.5 -1 -1.5

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

Fig.5.11 b: The triangular and dc voltge from simulation point of view.

69

0.05

Fig.5.12 a: The output voltage of comparator IC 741 pin 6, from practical point of view. (Flexible broad board and Hard copper board).

1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

Fig.5.12 b: The output voltage of comparator, from simulation point of view.

70

0.05

At frequency f= 2.05 K Hz

Fig.5.11 a: Ilustrate the triangular with dc voltge

1.5 1 0.5 0 -0.5 -1 -1.5 0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

Fig.5.11 b: The triangular and DC voltge from simulation point of view.

71

0.05

Fig.5.12 a: The output voltage of comparator IC 741 pin 6, from practical point of view. (Flexible broad board and Hard copper board).

1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

Fig.5.12 b: The output voltage of comparator, from simulation point of view.

72

0.05

At frequency f= 500 Hz

Fig.5.11 a: Ilustrate the triangular with dc voltge

1.5 1 0.5 0 -0.5 -1 -1.5

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

Fig.5.11 b: The triangular and dc voltge from simulation point of view.

73

0.05

Fig.5.12 a: The output voltage of comparator IC 741 pin 6, from practical point of view. (Flexible broad board and Hard copper board). 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

Fig.5.12 b: The output voltage of comparator, from simulation point of view.

74

0.045

0.05

- Compartor between triangular and sin wave

Triangle 725Hz 1.5

1

0.5

0

-0.5

-1

-1.5 0

0.01

0.02

0.03

0.04

0.05

75

0.06

0.07

0.08

0.09

0.1

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

-0.2

0

0.01

0.02

0.03

0.04

0.05

76

0.06

0.07

0.08

0.09

0.1

Triangle 500Hz and Sine 1KHz 1.5

1

0.5

0

-0.5

-1

-1.5 0

0.01

0.02

0.03

0.04

0.05

77

0.06

0.07

0.08

0.09

0.1

Triangle 225Hz

1.5

1

0.5

0

-0.5

-1

-1.5 0

0.01

0.02

0.03

0.04

0.05

78

0.06

0.07

0.08

0.09

0.1

PWM at Triangle 225Hz and Sine 1KHz. 1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

-0.2 0

0.01

0.02

0.03

0.04

0.05

79

0.06

0.07

0.08

0.09

0.1

Sine 1KHz

80

Triangle 725Hz and Sine 1KHz. 1.5

1

0.5

0

-0.5

-1

-1.5 0

0.01

0.02

0.03

0.04

0.05

81

0.06

0.07

0.08

0.09

0.1

Triangle 500Hz

82

PWM at Triangle 500Hz and Sine 1KHz.

83

Triangle 225Hz and Sine 1KHz

84

Finally the Graduation Project is illustrated in Fig.5.13. as a practical flexible & hard copper board of drive circuit under test.

Fig.5.13: Practical flexible & hard copper board of drive circuit under test.

85

CHAPTER 7 CONCLUSION

86

CONCLUSION The simulation and experimental implementation for the system is presented.

A fixed

structure controller is presented for four different converter types. The controller objective is to move the operating point of the system to its desired voltage. The converter duty cycle (D) is adjusted by the controller to track the system voltage.

87

A- References 1. http://en.wikipedia.org/wiki/Boost_converter 2. http://en.wikipedia.org/wiki/Buck_converter 3. http://en.wikipedia.org/wiki/Buck–boost_converter 4. http://en.wikipedia.org/wiki/Ćuk_converter 5. U.A.Bakshi and M.V.Bakshi. Electrical Drives And Control. 1st ed. Technical Publications

Pune,

2009.

Page

1-1

Published

by

Ohio

Electric

Motors: http://www.ohioelectricmotors.com/a-guide-to-electric-drives-and-DC-motor control-688#ixzz2StwEZqtL 6. N. K. De and P. K. Sen. Electric Drives. Prentice Hall of India, 2006. Page 1 Published by Ohio Electric Motors: http://www.ohioelectricmotors.com/a-guide-to-electric-drives-andDC-motor-control-688#ixzz2StxUzYio 7. Herman, Stephen L. Industrial Motor Control. 6th ed. Delmar Cengage Learning, 2010. Page 7 Published by Ohio Electric Motors: http://www.ohioelectricmotors.com/a-guideto-electric-drives-and-DC-motor-control-688#ixzz2StyCFF8u 8. http://www.vishay.com/docs/81865/4n32.pdf For IC 4N32 9. http://www.ti.com/lit/ds/symlink/lm741.pdf For IC 741 10. http://www.intersil.com/data/FN/FN2864.pdf For IC 8038 11. http://www.datasheetcatalog.com For IC 7414 12. www.fairchildsemi.com/ds/LM/LM7805.pdf For IC 78XX

88

CAPSTONE DESIGN PROJECT Project Submission

and ABET Criterion 3 a-k Assessment Report Project Title:

PRACTICAL DESIGN AND TESTING FOR DRIVE CIRCUIT OF MACHINE USING PULSE WIDTH MODULATION ( P.W.M )

DATE:

/ 2013

May

PROJECT ADVISORS:

Dr. Ahmed Oshaba

Team Members:

Design Project Information Percentage of project Content- Engineering Science % Percentage of project Content- Engineering Design % Other content % All fields must be added to 100%

40% 60% __________________

Please indicate if this is your initial project declaration or final project form (Final)

□ □

Do you plan to use this project as your capstone design project?

yes

Mechanism for Design Credit

□ Projects in Engineering Design

(Projects in Engineering Design)

Project Initial Start Version Final Project Submission Version

□ Independent studies in Engineering □ Engineering Special Topics

Fill in how you fulfill the ABET Engineering Criteria Program Educational Outcomes listed below Outcome (a), An ability to apply knowledge of mathematics, science, and engineering fundamentals.

Please list here all subjects (math, science, engineering) that have been applied in your project. For Example: let’s consider a MCUPE (Machine Control Using Power Electronics) system, this, include`: Electrical Machine, Control System, Drive Circuit, Converter, Control Theory, Feedback Systems, Electronic Control, Electrical Engineering, …. and so on.

89

Outcome (b). An ability to design and conduct experiments, and to critically analyze and interpret data.

Outcome (c). An ability to design a system, component or process to meet desired needs within realistic constraints such as economic, Environmental, Social, political, ethical, health and safety, manufacturability, and sustainability

In this part, if the project included experimental work for validation and/or verification purposes, please indicate that. Consider the pervious example in outcome (a) (i.e. MCUPE system) Validation of Actual Electrical Machine Control, …etc.

All projects should include a design component. By design we mean both physical and non physical systems. Designing a MCUPE system, this, or Electrical Machine, Control Part, Drive Circuit, Converter, Feedback Part, Electronic and IC. (integrate circuit) Component., Electrical, …. and so on would be considered a physical system. On the other hand, this project had a non-physical part, such as: the real data, supplied by the industry.

Outcome (d). An ability to function in multi-disciplinary teams.

Outcome (e). An ability to identify, formulate and solve engineering problems.

Outcome (f). An understanding of professional and ethical responsibility.

Outcome (g).

This outcome is achieved automatically by the fact that all projects composed of at least 3 students. However, if the project involved students from other departments, that would be a plus that is worth to be highlighted. The number of students in this project is 5 working together anther group in the laboratory. In order to meet this specific outcome, it would help if you have a Problem Statement section in your project report. If not, then briefly highlight how the “students” were able identify, formulate and solve the project’s problem. The main problem is how to control the motor speed using hardware and software programming. Here professional and ethical responsibility depends on the project context. The MCUPE project it would be not ethical.

Good report and good presentation will fulfill this outcome

An ability for effective oral and written communication.

Outcome (h). The broad education necessary to understand the impact of engineering solutions in a global economics, environmental and societal context .

Outcome (i). A recognition of the need for, and an ability to engage in life-long learning.

This outcome is usually fulfilled by highlighting the economic feasibility of the project, and emphasizing that the project would not harm the environment and does not negatively affect human subjects.

This outcome is fulfilled by suggesting a plan for future studies and what else could be done based on the outcome of the current project. In the future IGBT devices and data acquisition card for control system will be use.

A knowledge of contemporary issues.

Extensive literature review for machine control, types of drive circuit, converter (Buck, Cuk and Buck-Boost) and , overall control system of machine by the “students” for the current state of the art will fulfill this outcome.

Outcome (k).

List all technologies included in the project (hardware and software)

Outcome (j).

90

An ability to use the techniques, skills, and modern engineering tools necessary for engineering practice.

1) Using software program Matlab/simulink for simulation 2) Using hardware to build hard copper board the drive circuit

By signing below certify that this work is your own and fulfills the criteria described above Student Team Signatures __________________________ __________________________ __________________________ __________________________ __________________________

Project Advisor Signature

_________________________

College Coordinator of Capstone Projects

_________________________

Approved By

_________________________

91

B-Appendices B-1 List of Components TYPE

QUANTITY

PRICE IN S.R.

Resistance 220Ω

3

6

Resistance 3.3KΩ

3

6

Resistance 10KΩ

21

42

Resistance 91KΩ

6

12

Resistance 100KΩ

12

24

Rheostat 20KΩ

12

48

Diode

12

24

Capacitor 0.0015µF

6

12

Capacitor 0.1µF

6

12

Capacitor 10µF

15

30

Capacitor 2200µF

15

60

Transformer

3

180

Bridge

12

36

LM7812

6

24

LM7912

3

12

LM7815

3

12

LM7805

3

12

4N32

3

15

DM7414

3

15

LM741

3

15

ICL8038

6

120

IC Sockets

18

36

Junction points

3

9

Tray of connecting wires

6

30

Fine solder

1

40

Desoldering pump

1

35

Caustic

1

120

Peeler

1

40

Pliers

1

20

92

B-2 Integrated Circuits IC’S Datasheets

93

‫‪A Senior Project Final Report submitted in partial fulfillment‬‬ ‫‪of the requirement for the degree of BACHELOR OF Science (B.Sc.),‬‬

‫‪in Electrical Engineering‬‬ ‫) ‪May / 2013‬‬

‫‪( Completion Date‬‬

‫جـايــــعـة جــــــــــــازاٌ‬ ‫كـهـــــــٍــة انـــــــــهـــُـذســــــــــــة‬ ‫قـــســــى انـــهـُـذســـــــــة انــكــهــرتـــائـٍـــــــــة‬

‫تصمين عملي واختباس دائشة تغزيت‬ ‫لآلالث باستخذام تعذيل عشض النبضت‬ ‫رو القيمت والتشدد‬ ‫طالب فرٌق انعًم‬ ‫‪َ- 1‬ثٍم عشىي‬ ‫‪- 2‬اتراهٍى اتكر عسٍهً‬ ‫‪- 3‬سهطاٍَ حسٍٍ عسٍري‬ ‫‪- 4‬طارق قٍسً‬ ‫‪- 5‬شرٌف اتى انُىر عثذهلل‬

‫‪ٌ-6‬سٌذ عطٍف‬ ‫‪-7‬عثذهلل كرٌري‬ ‫‪ -8‬جاترانًانكً‬ ‫‪-9‬سعٍذ انتهٍذي‬ ‫‪-10‬يتعة انذوسري‬

‫يشرف انًشروع‬ ‫د ‪ /‬احمد سعيد عشيبة‬ ‫تقرٌر يشروع انتخرج يقذو نهحصىل عهى درجة انثكانىرٌىش‬ ‫فً انهُذسة انكهربائٌة‬

‫‪94‬‬

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