Click here to load reader

VOLTAGE TRACKING OF DC-DC BOOST CONVERTER USING

  • View
    222

  • Download
    0

Embed Size (px)

Text of VOLTAGE TRACKING OF DC-DC BOOST CONVERTER USING

  • VOLTAGE TRACKING OF DC-DC BOOST CONVERTER USING GAUSSIAN

    FUZZY LOGIC CONTROLLER

    SITI HASMAH BINTI JAMALI

    A project report submitted in partial

    fulfillment of the requirement for the award of the

    Degree of Master of Electrical Engineering

    Faculty of Electrical and Electronics Engineering

    Universiti Tun Hussein Onn Malaysia

    JANUARY 2012

  • v

    ABSTRACT

    DC-DC converters are electronic devices used to change DC electrical power

    efficiently from one voltage level to another. Operation of the switching devices

    causes the inherently nonlinear characteristic of the DC-DC converters including one

    known as the Boost converter. Consequently, this converter requires a controller with

    a high degree of dynamic response. Proportional-Integral- Differential (PID)

    controllers have been usually applied to the converters because of their simplicity.

    However, the main drawback of PID controller is unable to adapt and approach the

    best performance when applied to nonlinear system. It will sufer from dynamic

    response, produces overshoot, longer rise time and settling time which in turn will

    influenced the output voltage regulation of the Boost converter. Therefore, the

    implementation of practical Fuzzy Logic controller that will deal to the issue must be

    investigated. Fuzzy logic controller using voltage output as feedback for significantly

    improving the dynamic performance of boost dc-dc converter by using

    [email protected] software. The design and calculation of the components

    especially for the inductor has been done to ensure the converter operates in

    continuous conduction mode. The evaluation of the output has been carried out and

    compared by software simulation using MATLAB software between the open loop

    and closed loop circuit. The simulation results are shown that voltage output is able

    to be control in steady state condition for DC-DC boost converter by using this

    methodology.Scope of this project limited only one types that is Gaussian

    membership function.

  • vi

    ABSTRAK

    Penukar DC-DC adalah litar elektronik kuasa yang menukarkan satu aras voltan DC

    kepada satu aras voltan DC yang lain. Penukar Boost digunakan untuk meningkatkan

    voltan masukan untuk memenuhi syarat yang dikehendaki oleh sesuatu operasi. Operasi

    peranti pensuisan yang tak linear memerlukan pengawal Proportional-Integral-

    Differential (PID). Walau bagaimanapun, kelemahan utama pengawal PID tidak

    dapat menyesuaikan diri dan mendekati prestasi terbaik apabila merujuk kepada

    sistem tak linear seterusnya akan mempengaruhi peraturan voltan keluaran penukar

    Boost. Oleh itu, pelaksanaan pengawal Fuzzy Logik diperkenalkan bagi

    meningkatkan prestasi dinamik dengan menggunakan MATLAB @ Simulink

    perisian. Reka bentuk dan pengiraan komponen terutama bagi induktor telah

    dilakukan untuk memastikan penukar beroperasi dalam mod konduksi berterusan.

    Penilaian output telah dijalankan dan dibandingkan dengan perisian simulasi

    menggunakan perisian MATLAB antara litar gelung terbuka dan gelung tertutup.

  • vii

    TABLE OF CONTENTS

    TITLE i

    DECLARATION ii

    DEDICATION iii

    ACKNOWLEDGEMENT iv

    ABSTRACT v

    TABLE OF CONTENTS vii

    LIST OF TABLES ix

    LIST OF FIGURES x

    LIST OF SYMBOLS AND ABBREVIATIONS xiii

    CHAPTER 1 INTRODUCTION 1

    1.1 Project overview 1

    1.2 Problem statement 2

    1.3 Project objective 3

    1.4 Project scope 4

    1.5 Project report layout 4

    CHAPTER 2 LITERATURE REVIEW 6

    2.1 Existing Models 6

    2.2 DC-DC Converter 7

    2.3 Boost Converter 8

    2.3.1 Analysis for switch closed (On) 9 2.3.2 Analysis for switch closed (Off) 11

    2.3.3 Boost Converter modes of operation 13

  • viii

    2.4 PID Controller 14

    2.5 Fuzzy logic controller system 15

    2.5.1 Fuzzification 16

    2.5.2 Rule base 19

    2.5.3 Rules of Inference 20

    2.5.4 Defuzzification 21

    CHAPTER 3 METHODOLOGY 23

    3.1 Project Design 23

    3.2 Parameter for Boost Converter 25

    3.2.1 Selection of Power Switch

    (MOSFET) 27

    3.3 Proposed controller 27

    3.4 Fuzzy logic controller design 28

    3.4.1 Fuzzification interface 28

    3.4.2 Fuzzy inference mechanism 31

    3.4.3 Fuzzy rules 31

    3.4.4 Defuzzification interface 34

    CHAPTER 4 RESULT AND ANALYSIS 36

    4.1 Introduction 36

    4.2 Circuit Simulation for Boost Converter 36

    4.3 Analysis for Boost Converter 39

    4.3.1 Analysis for Open Loop Boost

    Converter 39

    4.3.2 Analysis for Boost Converter

    with PID Controller 44

    4.3.3 Analysis for Boost Converter

    with Fuzzy Logic Controller 48

  • ix

    CHAPTER 5 CONCLUSION AND RECOMMENDATION 53

    5.1 Conclusion 53

    5.2 Recommendation 54

    REFERENCES 55

  • ix

    LIST OF TABLES

    2.1 Example of rule base for air conditioner system 20

    3.1 Parameter for Boost Converter 25

    3.2 Rules for error and change of error 31

    4.1 Deviation of voltage resulted from open loop circuit

    Boost Converter 39

    4.2 Reading from Open Loop Boost Converter 43

    4.3 Deviation of voltage resulted from Boost Converter with PID 42

    4.4 Reading from Boost Converter with PID 48

    4.5 Deviation of voltage resulted from Boost Converter

    with Fuzzy Logic Controller 48

    4.6 Reading from Boost Converter with FLC 52

  • x

    LIST OF FIGURES

    2.1 A Boost Converter Circuit 8

    2.2 The Duty Cycle For Switching Period During Steady State 9

    2.3 The Equivalent Circuit of Boost Converter When the Switch S

    is Closed 10

    2.4 Analysis for switch closed 10

    2.5 The Equivalent Circuit of Boost Converter When the Switch S

    Open 11

    2.6 Analysis for switch opened (off) 11

    2.7 (a) CCM Mode (b) DCM Mode 14

    2.8 Structure of fuzzy logic controller system 16

    2.9 The features of a membership function (Kaehler, 1998) 17

    2.10 (a): Triangular membership function shape

    (b): Gaussian membership function shape

    (c ): Trapezoidal membership function shape

    (d): Generalized bell membership function shape

    (e): Sigmoidal membership function shape 19

    3.1 Block Diagram For Propose DC-DC Boost Converter Using

    Fuzzy Logic Controller 23 3.2 The Methodology Flow Chart 24

    3.3 The System Response 26

    3.4 Block diagram of proposed controller 27

    3.5 FIS Editor 29

    3.6 Gaussian membership function for (a) error and (b) change

    of error input variables (c) output for duty cycle 30

  • xi

    3.7 (a): Rule Base For Propose Fuzzy Logic Controller 32

    (b): Rule View For Propose Fuzzy Logic Controller 34

    3.8 Set-up for Defuzzification 35

    4.1 Simulation open loop Boost circuit using MATLAB Software 37

    4.2 Boost Converter with PID controller in Simulink 38

    4.3 Boost Converter with FLC controller in Simulink 38

    4.4 (a): Result for Iout and Vout (20% duty cycle)

    (b): Result for Inductor current (20% duty cycle)

    (c): Result for Iout and Vout (37.5% duty cycle)

    (d): Result for Iout and Vout (37.5% duty cycle)

    (e): Result for Inductor Current (37.5% duty cycle)

    (f): Result for Iout and Vout (50% duty cycle)

    (g): Result for Inductor Current (50% duty cycle) 40

    4.5 (a): Simulation Result Iout and Vout Boost Converter

    with PID (6.25v)

    (b): Simulation Result Inductor Boost Converter with PID (6.25v)

    (c): Simulation Result Iout and Vout Boost Converter with

    PID (8v)

    (d): Simulation Result Iout and Vout Boost Converter with

    PID (8v)

    (e): Simulation Result Inductor Current Boost Converter with

    PID (8v)

    (f): Simulation Result Iout and Vout Boost Converter with

    PID (10v)

    (g): Simulation Result Inductor Current Boost Converter with

    PID (10v) 44

    4.6 (a): Simulation Result Inductor Current Boost Converter with

    Fuzzy Logic Controller for 6.25V

    (b): Simulation Result Inductor Current Boost Converter with

    Fuzzy Logic Controller for 6.25V

    (c): Simulation Result Inductor Current Boost Converter with

    Fuzzy Logic Controller for 8V

  • xii

    (d): Simulation Result Inductor Current Boost Converter with

    Fuzzy Logic Controller for 8V

    (e): Simulation Result Inductor Current Boost Converter with

    Fuzzy Logic Controller for 10V

    (f): Simulation Result Inductor Current Boost Converter with

    Fuzzy Logic Controller for 10V 49

  • xiii

    LIST OF SYMBOLS AND ABBREVIATIONS

    e

    - degree of membership function of error

    e

    - degree of membership function of delta of error

    u

    - degree of membership function of voltage ouput

    o

    - maximum operator

    - output of COG

    - minimum operator

    B - Bisector of Area

    C - Capacitor

    CCM - Continuous Conduction Mode

    ce - Change of Er

Search related