Uncontrolled AC to DC Converters

1

Power Electronics

Lecture 2: Uncontrolled AC to DC Converters (Diode Rectifiers)

Lecturer: Dr. Mahdi Dargahi K. Semester 2, 2015 Curtin University University,, Perth, Australia

Trusted by over 1 million members

Try Scribd FREE for 30 days to access over 125 million titles without ads or interruptions! Start Free Trial Cancel Anytime.













Power Electronics Lecture 2

2

DIODE RECTIFIERS Introduction 1- Single phase half-wave diode rectifier

2- Battery charger

3- Single phase full wav wave e diode rectifier
















3

DIODE RECTIFIERS Block Diagram

AC DC
















4

DIODE RECTIFIERS Main issues in diode rectifiers

AC DC Single-phase

Resistive
















5

DIODE RECTIFIERS Single phase half-wave half-wave diode rectifier (R load)
















6

DIODE RECTIFIERS Single phase half-wave half-wave diode rectifier (R load) Example: Find average and rms values Example: of the output voltage and FF, RF and PF for the following circuit:


















7

DIODE RECTIFIERS Single phase half-wave half-wave diode rectifier (R load) The average output voltage V dc is defined as:


















8

DIODE RECTIFIERS Single phase half-wave half-wave diode rectifier (R load) The rms (root mean square) value of a periodic waveform is defined as:


















9

DIODE RECTIFIERS Single phase half-wave half-wave diode rectifier (R load) The form factor (FF) is defined as the ratio of the root-mean- square value (heating component) of a voltage or current cur rent to its average average value:


















10

DIODE RECTIFIERS Single phase half-wave half-wave diode rectifier (R load) Rectification Rectification efficiency: P dc

(0.3 (0.31 18V ) 

m

R

2


















11

DIODE RECTIFIERS How can we calculate the Power Factor (PF)?




















12


















13


















14


















15


















16






























































































































































































32

DIODE RECTIFIERS Voltage Doubler rectifier
















33

DIODE RECTIFIERS Voltage Doubler rectifier
















34

DIODE RECTIFIERS A three-phase, three-phase, four-wire system system
















35

DIODE RECTIFIERS Multiphase Star Rectifier
















36

DIODE RECTIFIERS Multiphase Star Rectifier

V1 has the highest magnitude compared to the other phases. Thus during this period D1 conducts and the rest of diodes are reverse biased. DC value of the output voltage for the case of 6-phase star rectifier:


















37

DIODE RECTIFIERS Multiphase Star Rectifier V2 >V1 and other phases, thus during this period, D1 is turned off and D2 is turned on.


















38

DIODE RECTIFIERS A three-phase half-wave half-wave rectifier rectifier with pure inductive inductive load


















39

DIODE RECTIFIERS A three-phase, full-bridge rectifier rectifier with resisti resistive ve load


















40



















41





















42


















43


















44


















45


















46













































































Uncontrolled AC to DC Converters

Recommend Documents