5-1 Copyright © 2003 by John Wiley & Sons, Inc. Chapter 5 Line-Frequency Diode Rectifiers Chapter 5 Diode Rectifiers
5-1Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Chapter 5
Diode Rectifiers
5-2Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Diode Rectifier Block Diagram
Uncontrolled utility interface (ac to dc)
5-3Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
A Simple Circuit
Resistive load
5-4Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
A Simple Circuit (R-L Load)
Current continues to flows for a while even after the input
voltage has gone negative
5-5Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Single-Phase Diode Rectifier Bridge
Large capacitor at the dc output for filtering and energy
storage
5-6Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Diode-Rectifier Bridge Analysis
Two simple (idealized) cases to begin with
5-7Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Redrawing Diode-Rectifier Bridge
Two groups, each with two diodes
5-8Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Waveforms with a
purely resistive load
and a purely dc current
at the output
In both cases, the dc-side
voltage waveform is the same
5-9Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Diode-Rectifier Bridge Input Current
Idealized case with a purely dc output current
5-10Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Diode-Rectifier Bridge Analysis with AC-
Side Inductance
Output current is assumed to be purely dc
5-11Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Understanding Current Commutation
Assuming inductance in this circuit to be zero
5-12Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Understanding Current Commutation (cont.)
Inductance in this circuit is included
5-13Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Current Commutation Waveforms
Shows the volt-seconds needed to commutate current
5-14Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Current Commutation in Full-Bridge Rectifier
Shows the necessary volt-seconds
5-15Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Understanding Current Commutation
Note the current loops for analysis
5-16Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Diode-Rectifier with a Capacitor Filter
Power electronics load is represented by an equivalent load
resistance
5-17Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Diode Rectifier Bridge
Equivalent circuit for analysis on one-half cycle basis
5-18Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Line-Voltage Distortion
PCC is the point of common coupling
5-19Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Distortion in voltage supplied to other loads
Line-Voltage Distortion
5-20Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Three-Phase, Full-Bridge Rectifier
Commonly used
5-21Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Three-Phase, Full-Bridge Rectifier: Redrawn
Two groups with three diodes each
5-22Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Three-Phase, Full-Bridge Rectifier Waveforms
Output current is
assumed to be dc
5-23Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Three-Phase, Full-Bridge Rectifier: Input
Line-Current
Assuming output current to be purely dc and zero ac-side
inductance
5-24Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
Three-Phase, Full-Bridge Rectifier
Including the ac-side inductance
5-25Copyright 2003
by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode
Rectifiers
3-Phase Rectifier: Current Commutation
output
current is
assumed to be
purely dc