Rectificadores No Controlados.ppt

04/08/23 EEL 4242 by Dr. M.H. Rashid 1

EEL 4242POWER ELECTRONICS

RECTIFICADORES CON DIODOS


Rectificadores Monofásicos de Media Onda

( ) 0

( )

2 2( ) 0

( )

1sin

2

1sin

2 2

2

mo dc m

mo dc

mo rms m

mo rms

VV V d

VI

R

VV V d

VI

R

Figure 3.1


Formsa de Onda de Entrada

2 2

2

21 1

dc dc dc ac rms rms

dcac rms dc

ac

rms ac

dc dc

rms

dc

P V I P V I

PV V V

P

V VFF RF

V V

VRF FF

V

Figure 3.2

22 21

21 1

1 1

( )

cos

1

cos cos

dc

s s

s s s

s s

s S S

s S S

S peak

S

PTUF DF

V I

I I IHF

I I

V I IPF

V I I

ICF

I


Rectificador de M.O. Con Carga RLFigure 3.3

( ) 0

( )

1sin

2

1 cos2

1 cos2

o dc m

m

mo dc

V V d

V

VI

R


Rectificador O.C. (Tap-central)

Figure 3.5

( ) 0

( )

2 2( ) 0

( )

22sin

22

2sin

2 2

2

mo dc m

mo dc

mo rms m

mo rms

VV V d

VI

R

VV V d

VI

R


Full-Wave Bridge Rectifier

Figure 3.6

( ) 0

( )

2 2( ) 0

( )

22sin

22

2sin

2 2

2

mo dc m

mo dc

mo rms m

mo rms

VV V d

VI

R

VV V d

VI

R


Bridge Rectifier (motor load)

Figure 3.7

1

4 sin sin 3 sin 5( ) ....

1 3 5

40.90

2

as

as a

I t t ti t

II I


Bridge Rectifier (RL load)

Figure 3.8

2 sin 0oo s o

diL Ri E V t for idt



( / )1

22 1

2 sin 0

2sin

tan ( / )

oo s o

R L to


V Ei t Ae

Z R

Z R L L R

• Case 1: Continuous conduction, Io >0

• Case 2: Discontinuous conduction, Io =0



( / )( / )( / )

0

2 2sin

1

0 0

R L to R L

V Ei t e

Z e R

for t and i



( / )( / )

0

1

tan

2 2sin sin

0

sin , ( ) 0

sin sin 0cos cos

R L to

om

V E V Ei t e

Z R Z R

for i

EAt t i t

V

x xe


Boundary of continuous and discontinuous (single-phase)

Figure 3.9


Multiphase Rectifiers

Figure 3.12

/ 2 2( ) 0

2cos

2 /

1 2sin

2 2

q

o rms m

m

V V dq

qV

q q

/

( ) 0

2cos

2 /

sin

q

o dc m

m

V V dq

qV

q


Three-Phase Bridge Rectifier

Figure 3.13


Waveforms and Conduction Times

/ 6

( ) 0

23 cos

2 / 6

3 31.654

o dc m

m m

V V d

V V

Figure 3.14

/ 2 2( ) 0

23 cos

2 /

3 9 31.6554

2 4

q

o rms m

m m

V V dq

V V


3-Phase Bridge Rectifier (RL Load)

Figure 3.15

22 sin

3 3

2 sin 0

ab ab

oo ab o

v V t for t



Three-Phase Bridge Rectifier (RL load)

( / )1

22 1

2 sin 0

2sin

tan ( / )

oo ab o

R L tabo


V Ei t Ae

Z R

Z R L L R




Three-Phase Bridge (RL load)

( / )( /3 )( / )( /3 )

0

sin 2 / 3 sin / 32sin

1

/ 3 2 / 3 0

R L tabo R L

V Ei t e

Z e R

for t and i



( / )( /3 )

( / )( /3 )

( )2 tan

( )2 tan

0 ( .3.47)

sin 2 / 3 sin / 320

1

sin 2 / 3 sin / 3( ) cos

21

o

R Lab

R L

ab

Setting I in Eq

eV E

Z e R

eEx

Ve


Boundary of continuous and discontinuous (three-phase)

Figure 3.16


DC Filters

Figure 3.18


AC Filters

Figure 3.19


Single-Phase Rectifier with C-Filter

Figure 3.22


Single-Phase Rectifier with C-Filter

Figure 3.22

( )

( )( )

( )

( )

4

2 2 4 2

1

2(4 1)

mo dc m

e

r pp mrms ripple

e

rms ripple

o dc e

VV V

fRC

V VV

fRC

VRF

V fRC


Output Voltage with C-Filter

Figure 3.26


Effects of Source Inductances

Figure 3.27

1 2 3

1 2 3

2 ( )

6x dc

dc

V f L L L I

fLI if L L L


Summary

• What was the major idea?

• What was the muddiest idea?

• Diode rectifiers convert an ac voltage to a dc voltage. • The output voltage contain ripples which can be removed by filters. • Depending on time constant of the load, the load current may be discontinuous. • Line inductances cause overlap and reduce the effective dc output voltage.

Rectificadores No Controlados.ppt

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