Chapter 1 Power Electronic Systems Introduction Power Electronics

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Chapter 1 Power Electronic Systems • Introduction • Power Electronics versus Linear Electronics •

Chapter 1 Power Electronic Systems • Introduction • Power Electronics versus Linear Electronics • Applications Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -1

Power Electronic Systems • Block diagram • Role of Power Electronics • Reasons for

Power Electronic Systems • Block diagram • Role of Power Electronics • Reasons for growth Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -2

Linear Power Supply • Series transistor as an adjustable resistor • Low Efficiency •

Linear Power Supply • Series transistor as an adjustable resistor • Low Efficiency • Heavy and bulky Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -3

Introduction: Switching Power Electronics Linear regulator Goal: control VX such that Vo=Vo, REF Plus:

Introduction: Switching Power Electronics Linear regulator Goal: control VX such that Vo=Vo, REF Plus: simple accurate, high-bandwidth Minus: low efficiency Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -4

Switching power converters Vo(t) VIN Add filtering Vo(t) VIN Add real devices Electrónica de

Switching power converters Vo(t) VIN Add filtering Vo(t) VIN Add real devices Electrónica de Potência © 2008 Jose Bastos <Vo> Note: -only lossless elements -L, C energy storage Chapter 1 Introduction 1 -5

Switch-Mode Power Supply • Transistor as a switch • High Efficiency • High-Frequency Transformer

Switch-Mode Power Supply • Transistor as a switch • High Efficiency • High-Frequency Transformer Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -6

Basic Principle of Switch-Mode Synthesis • Constant switching frequency • pulse width controls the

Basic Principle of Switch-Mode Synthesis • Constant switching frequency • pulse width controls the average • L-C filters the ripple Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -7

Application in Adjustable Speed Drives • • Conventional drive wastes energy across the throttling

Application in Adjustable Speed Drives • • Conventional drive wastes energy across the throttling valve to adjust flow rate Using power electronics, motor-pump speed is adjusted efficiently to deliver the required flow rate Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -8

Power Processor as a Combination of Converters • Most practical topologies require an energy

Power Processor as a Combination of Converters • Most practical topologies require an energy storage element, which also decouples the input and the output side converters Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -9

Uninterruptable power supply - UPS 220 V Batt 24 V ~ load • Converter

Uninterruptable power supply - UPS 220 V Batt 24 V ~ load • Converter 1 rectifies line-frequency ac into dc • Capacitor acts as a filter; stores energy; decouples • Converter 2 synthesizes line-frequency ac to load Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -10

Power Flow through Converters • Converter is a general term • An ac/dc converter

Power Flow through Converters • Converter is a general term • An ac/dc converter is shown here • Rectifier Mode of operation when power from ac to dc • Inverter Mode of operation when power from ac to dc Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -11

Scope and Applications Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1

Scope and Applications Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -12

Interdisciplinary Nature of Power Electronics Electrónica de Potência © 2008 Jose Bastos Chapter 1

Interdisciplinary Nature of Power Electronics Electrónica de Potência © 2008 Jose Bastos Chapter 1 Introduction 1 -13