Title Page
Contents
ABSTRACT 13
국문초록 15
CHAPTER 1. INTRODUCTION 17
1.1. Objectives 19
1.2. Methodology 20
1.3. Dissertation Outline 20
1.4. Literature Review 21
CHAPTER 2. PROPOSED CONVERTER 28
2.1. Operational Modes in CCM and DCM 33
2.2. Steady State Voltage Gain at CCM 39
2.3. Steady State Voltage Gain at DCM 43
2.4. Inductor Current in DCM 50
2.5. Semiconductor Components Stress 51
2.6. Air-Cored Magnetic Component Design 54
2.6.1. Solenoid Inductor 54
2.6.2. Planar Spiral Inductor 55
2.6.3. Toroidal Inductor 56
2.6.4. Tapped-Inductor 57
2.7. Capacitor Volume Design 60
2.8. Power Loss Calculations 60
2.8.1. Inductor Power Loss 61
2.8.2. Switch Power Loss 61
2.8.3. Diode Power Loss 62
2.8.4. Capacitor Power Loss 62
CHAPTER 3. CONVERTER SPECIFICATIONS AND COMPONENTS SELECTION 63
3.1. Converter Specifications 63
3.2. Components Design and Selection 64
3.2.1. Capacitors Selection 65
3.2.2. Design of Tapped-Inductor 65
CHAPTER 4. RESULTS AND DISCUSSION 83
4.1. Simulation Verification 83
4.2. Experimental Setup 86
4.3. Experimental Results 88
4.4. Loss Breakdown 91
4.5. Comprehensive Comparison with Existing Topologies 92
CHAPTER 5. CONCLUSION 94
REFERENCES 96
[Table 3-1] Design Specifications of Converter 64
[Table 3-2] Hardware Components Specifications 65
[Table 3-3] Simulated Inductance and Resistance 79
[Table 3-4] Parameters of fabricated inductor 82
[Table 4-1] Comparison with latest Step-up Topologies 93
[Figure 1-1] Block diagram of power conversion system. 18
[Figure 1-2] Circuit diagram of Dickson Voltage Multiplier. 23
[Figure 1-3] Circuit diagram of Cockcroft-Walton Voltage Multiplier. 23
[Figure 1-4] Fixed shunt resistor cell balancer. 25
[Figure 1-5] Multiple switched capacitor cell balancer. 25
[Figure 1-6] Boost converter balancing topology. 25
[Figure 2-1] Circuit Diagram of Proposed Converter. 29
[Figure 2-2] (a) Switch voltage spikes. (b) Effect of switch parallel capacitor. 30
[Figure 2-3] Important theoretical (ideal) waveforms of proposed converter at DCM. 35
[Figure 2-4] Important theoretical (ideal) waveforms of proposed converter at CCM. 36
[Figure 2-5] First mode of operation [t₀ - t₁], DCM and CCM. 37
[Figure 2-6] Second mode of operation [t₁ - t₂], DCM and CCM. 37
[Figure 2-7] Third mode of operation [t₃ - t₄], DCM and CCM. 38
[Figure 2-8] Fourth mode of operation [t₃ - t₄], DCM only. 38
[Figure 2-9] Voltage gain of proposed converter in CCM against duty cycle and turn ratio n. 43
[Figure 2-10] Tapped Inductor and untapped inductor current in DCM 45
[Figure 2-11] Voltage gain of proposed converter in DCM for different load conditions and duty cycle D. 48
[Figure 2-12] Voltage gain of proposed converter in DCM for different L₁ inductance and duty cycle D. 49
[Figure 2-13] Voltage gain of proposed converter in DCM for different values of r=rds,on + rL1 and duty cycle D.[이미지참조] 50
[Figure 2-14] Switch voltage stress for different turn ratio n and voltage gain. 52
[Figure 2-15] Geometry of air-core solenoid inductor. 55
[Figure 2-16] Geometry of air-core spiral inductor. 56
[Figure 2-17] Geometry of air-core toroidal inductor. 57
[Figure 2-18] Open circuit test of transformer. 58
[Figure 2-19] Short circuit test of transformer. 59
[Figure 3-3] Round wire wound solenoid inductor. 67
[Figure 3-4] Flat copper wound solenoid. 68
[Figure 3-5] Inductor geometry. 70
[Figure 3-6] Flow Chart of Inductor Design. 71
[Figure 3-7] Change in Inductance for different values of R and w. 72
[Figure 3-8] Change in Inductance for different values of R and t. 73
[Figure 3-9] Mesh of FEM simulated Inductor. 75
[Figure 3-10] Comparison of Calculated and FEM Simulated Inductance. 76
[Figure 3-11] Magnetic Flux Density of Simulated Inductor. 77
[Figure 3-12] Current Density of Simulated Inductor. 77
[Figure 3-13] Change in Current Density with distance. 78
[Figure 3-14] Change in Resistance with frequency. 78
[Figure 3-15] Fabricated Tapped-Inductors. 81
[Figure 4-1] Simulated waveforms of Proposed Circuit (a) Output Voltage (b) Output Current (c) Inductor Current. 84
[Figure 4-2] Simulated waveforms of proposed circuit (a) PWM (b) Switch Voltage (c) Switch Current. 85
[Figure 4-3] Designed PCB circuit. 87
[Figure 4-4] Experimental setup. 87
[Figure 4-5] Experimental verification of proposed converter. 89
[Figure 4-6] Soft switching verification of proposed converter. 89
[Figure 4-7] Efficiency curve for varying input voltage. 90
[Figure 4-8] Efficiency curve for varying load. 90
[Figure 4-9] Loss breakdown for converter components. 92