diode rectifiers [compatibility mode]

5-1Copyright 2003

by John Wiley & Sons, Inc.Chapter 5 Line-Frequency Diode

Rectifiers

Chapter 5

Diode Rectifiers

5-2Copyright 2003


Rectifiers

Diode Rectifier Block Diagram

Uncontrolled utility interface (ac to dc)

5-3Copyright 2003


Rectifiers

A Simple Circuit

Resistive load

5-4Copyright 2003


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


Rectifiers

Single-Phase Diode Rectifier Bridge

Large capacitor at the dc output for filtering and energy

storage

5-6Copyright 2003


Rectifiers

Diode-Rectifier Bridge Analysis

Two simple (idealized) cases to begin with

5-7Copyright 2003


Rectifiers

Redrawing Diode-Rectifier Bridge

Two groups, each with two diodes

5-8Copyright 2003


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


Rectifiers

Diode-Rectifier Bridge Input Current

Idealized case with a purely dc output current

5-10Copyright 2003


Rectifiers

Diode-Rectifier Bridge Analysis with AC-

Side Inductance

Output current is assumed to be purely dc

5-11Copyright 2003


Rectifiers

Understanding Current Commutation

Assuming inductance in this circuit to be zero

5-12Copyright 2003


Rectifiers

Understanding Current Commutation (cont.)

Inductance in this circuit is included

5-13Copyright 2003


Rectifiers

Current Commutation Waveforms

Shows the volt-seconds needed to commutate current

5-14Copyright 2003


Rectifiers

Current Commutation in Full-Bridge Rectifier

Shows the necessary volt-seconds

5-15Copyright 2003


Rectifiers

Understanding Current Commutation

Note the current loops for analysis

5-16Copyright 2003


Rectifiers

Diode-Rectifier with a Capacitor Filter

Power electronics load is represented by an equivalent load

resistance

5-17Copyright 2003


Rectifiers

Diode Rectifier Bridge

Equivalent circuit for analysis on one-half cycle basis

5-18Copyright 2003


Rectifiers

Line-Voltage Distortion

PCC is the point of common coupling

5-19Copyright 2003


Rectifiers

Distortion in voltage supplied to other loads

Line-Voltage Distortion

5-20Copyright 2003


Rectifiers

Three-Phase, Full-Bridge Rectifier

Commonly used

5-21Copyright 2003


Rectifiers

Three-Phase, Full-Bridge Rectifier: Redrawn

Two groups with three diodes each

5-22Copyright 2003


Rectifiers

Three-Phase, Full-Bridge Rectifier Waveforms

Output current is

assumed to be dc

5-23Copyright 2003


Rectifiers

Three-Phase, Full-Bridge Rectifier: Input

Line-Current

Assuming output current to be purely dc and zero ac-side

inductance

5-24Copyright 2003


Rectifiers

Three-Phase, Full-Bridge Rectifier

Including the ac-side inductance

5-25Copyright 2003


Rectifiers

3-Phase Rectifier: Current Commutation

output

current is

assumed to be

purely dc

diode rectifiers [compatibility mode]

Documents