Power Converter Design Optimization

Preface

Part 1: Resistance Converters

1 Power Conversion

Classification of Power Converters 1

Basic Switched Converter Function 3

Notation and Terminology 4

Magnetic or Electric Energy Storage 6

Waveforms and Optimization 8

Converter Design Considerations 12

   Power Transfer Circuit and Waveforms 13

   Magnetics 14

   Parasitic Resonances 16

   Control 18

2 PWM-Switch Circuits

The PWM-Switch 20

PWM-Switch Configurations 21

   CP (Buck) Configuration 23

   CA (Boost) Configuration 25

   CL Configuration 26

Configuration Characteristics 26

Transistor and PWM-Switch Analogs 28

Power-Transfer Circuit Waveforms 31

PWM-Switch Power Flows 32

Inductor Power 32

3 Common-Passive (Buck) Circuits

Forward Power-Transfer Circuits 35

Forward Circuit with Deflux Winding 41

CP Chopper Switch Voltage Clamp 44

Series-Switch Forward Circuit 47

Multiple Outputs 49

Distributed Forward Circuit 49

Distributed-Inductor CP Circuit 51

Interleaved Circuits 52

Full-Bridge CP Circuit 54

Secondary Rectifier Circuits 56

Half-Bridge CP Circuit 60

Half-Bridge Flux-Charge Balance 68

Half-Bridge Peak-Current Stabilization 70

Incremental CCM Model 72

Half-Bridge Dynamic Stability 75

Complementary Forward Circuit 77

Push-Pull CP Circuits 79

CP High-Side Push-Pull Circuit 83

Series-Switch and Push-Pull CPs 86

Push-Pull Chopper 87

Push-Pull Switch Voltage Clamp 88

4 Common-Active (Boost) Circuits

CA Circuit Power Flow 92

Current-Driven Half-Bridge Circuit 91

Tapped CA-CL Circuits 95

Distributed-Inductor CA Circuit 99

Boost Push-Pull Circuit 101

Optimal Form Factors 106

Optimal BPP Duty-Ratio 108

BPP Maximum Δλ 111

BPP Magnetics Design Power 112

BPP Inductor-Transformer Minimization 113

BPP Open-Circuit Fault 115

Boost Push-Pull with Three Switches 117

Interleaved BPP Circuit 119

5 Common-Inductor Circuits

Series-Switch CL Circuit 125

Isolated CL - The Flyback Circuit 124

Flyback Average Currents 133

Flyback Circuit Energy 135

Flyback Circuit with Deflux Winding 137

RC Leakage-Inductance Clamps 140

Minimalist Flyback Circuit 145

   Off-Grid Flyback Circuit 151

Flyback Charger Design 157

Minimum-Time CCM Charger Design 159

   Charger Control 159

   Duty-Ratio Range and Turns Ratio 161

   Current Ratcheting at Low Vo 163

   CCM Charger toff (vO) 167

PG1 Flyback Charger 169

   Off-Time Generator Circuit 170

   Variable-Frequency Charging Time 174

Fixed-Frequency Charger Design 175  

   CCM Charging Dynamics 177

   DCM Charging Dynamics 178

   Total Fixed-Frequency Charging Dynamics 179

   Time-Averaged Versus Voltage-Range-Averaged Currents 180

DCM Flyback Duty-Ratio Optimization 181

Distributed Flyback Circuit 188

Complementary CCM Flyback Circuit 189

Active-Tapped CA-CL Circuit 192

Parallel Active-Tapped CA-CL Circuit 196

Passive-Tapped CA-CL Circuit 200

Flyback CP-CL Dual-Output Circuit 203

Forward CP-CL Circuit Example 208

Active-Tapped CL Chopper 213

6 Ćuk-Switch Circuits

Multi-Stage PWM-Switch Circuits 219

Topological Development of Ćuk Circuit 221

Ćuk-Circuit Transfer Ratio 223

Ćuk-Switch Configurations 224

   Ćuk-Switch CS 225

   Ćuk-Switch CA 226

   Ćuk-Switch CP 227

Four-Terminal Ćuk-Switch Circuits 229

   SEPIC Configuration 233

   Inverse Ćuk (–Ćuk) Circuit  234

   Inverted-SEPIC (–SEPIC) 236

Ćuk-Switch Power Flow 237

   Recirculation of Power 239

Reactance Power Ratings over Vg Range 241

   Design Example 244

Ćuk-Switch Capacitor Voltage Ripple 246

Ćuk Circuit Design Equations 248

Ćuk Circuit with Multiple Transductors 251

SEPIC Circuit Design Equations 252

Switch-Tapped SEPICs 257

   Primary Switch-Tapped SEPIC 258

   Secondary Switch-Tapped SEPIC 260

   Dual Switch-Tapped SEPIC 262

   Boosted Dual Switch-Tapped SEPIC 265

Cc-Tapped SEPICs 267

Tapped SEPIC with Multiple Outputs 271

Push-Pull SEPIC 273

Ćuk-Switch Multistage Circuits 275

Ćuk-Switch Dual-Mode Circuits 278

Ćuk-Switch SEPIC-CP Circuit 280

Multiple Output –Ćuk, –SEPIC 283

Ćuk-Switch 1 – D/D’ Circuits 285

Ćuk-Switch and Push-Pull Performance 287

Isolated Ćuk-Switch CS Circuit 290

Isolated Ćuk-Switch CP Circuit 295

Isolated SEPIC Circuit 296

Primary-Tapped IsoĆuk Circuit 296

Secondary-Tapped SEPIC Circuit 300

7 Ripple-Current Steering

Coupled Inductor and Transformer Behaviors 302

Transductor Current Steering 30?

Transductor Circuit Model 304

   Constant-Current Transductor Conditions 308

Ripple-Steered PWM-Switch Circuits 311

      Four Levels of Current-Steering Analysis 314

Ćuk Circuit with Constant Port Currents 315

Flyback Secondary-Side Ripple Steering 321

Flyback Primary-Side Ripple Steering 327

Series Inductance Notch Reduction 332

IsoĆuk Circuit with Series Inductance 333

BPP (CA) Coupled Series Inductance 335

Weinberg (CP) Circuit 337

Forward (CP) Secondary Ripple Steering 339

Ripple Current in Ćuk-Switch Cc 339

8 Zero-Power-Switched Circuits

Zero-Power Switching 343

Resonance 348

Resonant Horizontal Flyback Circuit 352

Constant-toff ZVS QR CP Circuit 355

ZCS QR CP Circuit 356

Multiresonant Circuits 358

Resonant Series-Switch Forward Circuit 363

Half-Bridge Series-L QR Circuit 366

Series-Inductor ZCS-DCM Circuit 369

   ZCS Secondary Behavior 371

   DCM Resonance 376

   Current Waveform 377

   Peak, Average, and RMS Currents 380

   DCM-CCM Boundary 383

   Maximum Output Power 384

   Incremental Gain 386

   Incremental Output Resistance 389

   Inductance Moved to Primary Circuit 390

   Performance Evaluation 390

390 pages

 

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