PALESTINE POLYTECHNIC UNIVERSITY (PPU) POWER ELECTRONICS Dr. Sameer Khader Spring
description
Transcript of PALESTINE POLYTECHNIC UNIVERSITY (PPU) POWER ELECTRONICS Dr. Sameer Khader Spring
PALESTINE POLYTECHNIC UNIVERSITY(PPU)
POWER ELECTRONICS
Dr. Sameer Khader
Spring 2003 / 20042005/2006
Chapter 3-B Three-Phase Rectifiers
Chapter 3-A : Single Phase Rectifiers
Rectifier Classification
Power Electronics
Chapter 3
Uncontrolled Rectifiers
Un controlled Rectifiers
Single-PhaseRectifiers
Three-Phase rectifiers
Half-Wave Full-Wave
A: s1_1
Power Electronics
Chapter 3 : A
Single –Phase Uncontrolled Rectifiers
Single-Phase Rectifiers
Half-Wave “HW”
Full Wave“FW”
Bridge circuit Center tape
A: s1_1
Power Electronics
Chapter 3 : B
Three –Phase Uncontrolled Rectifiers
Three-Phase Rectifiers
Half-Wave “HW”
Full Wave“FW”
Three-Phase Half Wave Uncontrolled I- With Resistive Load Principle of operation :
1-Each diode must conduct for 120 dg while the anode voltage is maximum positive comparing with the other anode voltages .
2- Each phase voltage is connect to the load for the time of 120 dg.
3-The source ( phase) current is unsymmetrical
because it’s flow only during the positive half cycles .
Conclusion : 1- Low ripples , comparing with single-phase rectifier 2- Relatively acceptable efficiency and TUF 74 %3-There is a dc component in the source current (heavy saturated transformer)4- The output ripples are three-times the supply frequency .5- The diode inverse voltage is 1.731 Vm .
PIV
Vout
Ic
Vdiode
II- Three Phase Rectifier with R-L Load
The existing of inductance in the rectification circuit (
supply transformer & load inductance),leads to: 1- Voltage reduction in the average output voltage; 2- Current deformation of the output & phase current 3- Increasing the harmonic specter, therefore , increasing the harmonic losses .
Vdc L 0( ) Vdc L0( ) VL 0
V 3 Idc Lc fLc fThe output voltage :
In every commutation interval, two diodes operate together for angle Which called overlapping angle .
III- Three Phase Rectifier with failed diode
Vdc d1( ) failed Vdc0 11
3 VxVdc0
V4
T0
6
tVmcos tdThe output
voltage
The load current
The loadcurrents
The loadvoltage
The diode
voltage
.
The mathematical equations of HW – Three Phase Rectifier
IdcVdc
R
Vdc
2- The RMS voltage & current:
IrmsVrms
R
Vrms
3 - The output average & AC power:
Pdc Vdc IdcVdc
4 - The rectification efficiency: Pdc
Pac
Pdc
Pac
5- The transformer utility factor:
Pac Vrms IrmsVrms Irms
TUFPdc
VA( ) rating
Pdc
VA rating
where
8- The Ripple Factor :
1- The average voltage & current :
VA( ) rating 3 Vs IsVA( ) rating Vs Is
6 - The source current:
Vrms3
0
3
tVmcos t( )2d 0.840Vm
3
7 - The diode average current :
Idav1
0
3
tIm cos t( ) d 0.33Idc
8 - The diode rms current :
Idr1
0
3
tImcos t( )2d
Irms
3
1
Is3
0
3
tIm. cos t( )2d 0.48Im Irms
0
3
tIm. cos t( )2d
Vdc3
0
3
tVm cos t( ) d 3 3Vm
2
7 - The Form factor :FF Vrms
Vdc1.015
RF FF2 1 18 %
9- Diode PIV : PIV Va Vb 3 VmVa Vb Vm
Three-Phase Full Wave Uncontrolled I- With Resistive Load Principle of operation :
1-Each diode from anode group will conduct for 120 dg while the anode voltage is maximum positive comparing with the other anode voltages . And one diode from cathode group also conduct for 120 dg, while the cathode voltage is maximum negative .
2- Each diodes group is connect to the load for a time of 60 dg.
3-The source ( phase) current is symmetrical,
therefore no saturation effect
4- the supply voltage connected to the load is line voltage .
Conclusion :
1- Low ripples , comparing with another circuits (4% ripples), therefore no need of filter 2- Extremely high efficiency efficiency and TUF > 96%3-There is no dc component in the source current , therefore minimized losses4- The output ripples are with six-times the supply frequency .5- The diode inverse voltage is 1.731 Vm .6- the phase rms current is 81% of the load rms value .7- This circuit find widespread applications in wide range of the power specter .
II- FW Rectifier with R-L load
Vdc L 0( ) Vdc L0( ) VL 0
V 6 Idc Lc fLc f
The output average voltage:
Load current
Phasecurrent
Output voltage
Phase current
.
Mathematical Modeling of FW – Three Phase Rectifier
IdcVdc
R
Vdc
2- The RMS voltage & current:
IrmsVrms
R
Vrms
3 - The output average & AC power:
Pdc Vdc IdcVdc
4 - The rectification efficiency: Pdc
Pac
Pdc
Pac
5- The transformer utility factor:
Pac Vrms IrmsVrms Irms
TUFPdc
VA( ) rating
Pdc
VA rating
where
9- The Ripple Factor :
1- The average voltage & current :
VA( ) rating 3 Vs IsVA( ) rating Vs Is
6 - The source current:
7 - The diode average current :
8 - The diode rms current :
7 - The Form factor :
10- Diode PIV : PIV Va Vb 3 VmVa Vb Vm
Vdc6
0
6
tVab t( ) d 3 3Vm
Vrms6
0
6
tVab t( )( )2d 1.655Vm
6
Is8
2 0
6
tVab t( )
R
2
d 0.7804ImL
0
6
tVab t( )
R
2
d
ImL 3Vm
R
Vm
Idav4
2 0
6
tImL cos t( ) d 0.318ImL
Idr4
2 0
6
tImLcos t( )2d
Irms
3
4
2
Is Irms4
6Irms
RF FF2 1 4 %2 1FFFF Vrms
Vdc1.0006
Single Phase Half-Wave Circuit
0.000ms 30.00ms 60.00ms 90.00ms
30.00 V
10.00 V
-10.00 V
-30.00 V
A: v1_1
0.000ms 30.00ms 60.00ms 90.00ms
30.00 V
20.00 V
10.00 V
0.000 V
-10.00 V
A: s1_1
0.000ms 30.00ms 60.00ms 90.00ms
25.00mA
-25.00mA
-75.00mA
-125.0mA
A: r1[i]
0.000ms 30.00ms 60.00ms 90.00ms
30.00 V
20.00 V
10.00 V
0.000 V
-10.00 V
A: s1_2
D1DIODE
S1
C130uF
50 Hz
V1-30/30V
R1200
D1DIODE
S1
C130uF
50 Hz
V1-30/30V
R1200
T12TO1
50 Hz
V2-30/30V
C230uF
S2
D2DIODE
R2200
T12TO1
50 Hz
V2-30/30V
C230uF
S2
D2DIODE
R2200
Supply voltage
Output voltageWithout C
Output voltageWith C
Load current with C
Conclusion :
1- High ripples , therefore large value of capacitor is required 2- Poor efficiency and TUF ~28%--31%3- Dc component in the source current ( heavy saturated transformer ) 4- The output ripples have the same frequency equals the source frequency .
S1
C1
30uF
D1BRIDGE
50 Hz
V1-30/30V
R1200
0.000ms 30.00ms 60.00ms 90.00ms
30.00 V
20.00 V
10.00 V
0.000 V
-10.00 V
A: s1_1
S1
C1
30uF
D1BRIDGE
50 Hz
V1-30/30V
R1200
0.000ms 30.00ms 60.00ms 90.00ms
30.00 V
20.00 V
10.00 V
0.000 V
-10.00 V
A: s1_2
Single phase Uncontrolled Bridge rectifiers
1-Electrical circuit without filtering capacitor
1-Electrical circuit with filtering
capacitor
Conclusion :
1- Low ripples , therefore small value of capacitor is required 2- Relatively high efficiency and TUF 81 %3- No dc component in the source current ( no-saturation Effect in the transformer4- The output ripples have twice frequency with respect to the source .
The mathematical equationsof FW Bridge Rectifier
IdcVdc
R
Vdc
- The RMS voltage:
IrmsVrms
R
Vrms
- The output average & AC power:
Pdc Vdc IdcVdc
- The rectification efficiency: Pdc
Pac
Pdc
Pac
- The transformer utility factor:
Pac Vrms IrmsVrms Irms
TUFPdc
VA( ) rating
Pdc
VA rating
- for FW- bridge…..
- for FW- center tape IsIrms
2
Irms
Is IrmsIrms
whereVA( ) rating Vs IsVA( ) rating Vs Is
VA( ) rating 2 Vs IsVA( ) rating Vs Is
- The ripple factor: RF FF2 12 1FF
1- The main parameters : * rectification output parameters : - Average output voltage & current:
Vdc2
T0
T
2 tVm sin t( ) d
- The harmonic factor
HFIs
Is1
2
12
1Is
Is1; HF= 1.11
Vrms
0
T
2
tVmsin t2d
2
TVmsin t
The mathematical equationsof HW Rectifier
IdcVdc
R
Vdc
- The RMS voltage:
IrmsVrms
R
Vrms
- The output average & AC power:
Pdc Vdc IdcVdc
- The rectification efficiency: Pdc
Pac
Pdc
Pac
- The transformer utility factor:
Pac Vrms IrmsVrms Irms
TUFPdc
VA( ) rating
Pdc
VA rating
Is IrmsIrms
where
VA( ) rating Vs IsVA( ) rating Vs Is
- The form factor :
- The ripple factor: RF FF2 12 1FF
1- The main parameters : * rectification output parameters : - Average output voltage & current:
Vdc1
T0
T
2 tVm sin t( ) d
- The harmonic factor
HFIs
Is1
2
12
1Is
Is1
; FF= 1.57
Vrms
0
T
2 tVmsin t
2d1
TVmsin t
apparent power
source current
Single-Phase Rectifier – Center Tap
D512F120
D412F120
60 Hz
V2 5TO1CT
R5500
0.000ms 15.00ms 30.00ms 45.00ms
20.00 V
10.00 V
0.000 V
-10.00 V
-20.00 V
A: r5_2
Conclusion :
1- Low ripples , therefore small value of capacitor is required 2- Relatively high efficiency and low TUF ~ 57%3- No dc component in the source current ( no-saturation Effect in the transformer4- The output ripples have twice frequency with respect to the source .5- The diode PIV voltage is twice the supply voltage
IdcVdc
R
Vdc
- The RMS voltage:
IrmsVrms
R
Vrms
- The output average & AC power:
Pdc Vdc IdcVdc
- The rectification efficiency: Pdc
Pac
Pdc
Pac
- The transformer utility factor:
Pac Vrms IrmsVrms Irms
TUFPdc
VA( ) rating
Pdc
VA rating
- for FW- center tape IsIrms
2
Irms
where
VA( ) rating 2 Vs IsVA( ) rating Vs Is
- The form factor :
- The ripple factor: RF FF2 12 1FF
1- The main parameters : * rectification output parameters : - Average output voltage & current:
Vdc2
T0
T
2 tVm sin t( ) d
- The harmonic factor
HFIs
Is1
2
12
1Is
Is1
; FF= 1.11
Vrms
0
T
2
tVmsin t2d
2
TVmsin t
Mathematical Equations of FW Rectifier – Center Tap
+51 Volt Power Supply D412F120
D3DIODES1A
+
C1100uF
2TO1
60 Hz
V1-170/170V
D118DB10
D21N4757
Q12N2222A
+
C2100uF
R1680 R2
50
Additional Circuits
0.000ms 10.00ms 20.00ms 30.00ms
125.0 V
75.00 V
25.00 V
-25.00 V
A: r2_2
0.000ms 10.00ms 20.00ms 30.00ms
125.0 V
75.00 V
25.00 V
-25.00 V
A: r2_2
Without stabilizer
With stabilizer
Thyristor and Triac Circuits
D1DIODE
+
C10.9uF
R15k 30%
SCR12N506450 Hz
V1-220/220V
B A
R2100
B A
D1DIODE
+
C10.9uF
R15k 30%
SCR12N506450 Hz
V1-220/220V
B A
R2100
20.00ms 35.00ms 50.00ms 65.00ms
2.250 A
1.750 A
1.250 A
0.750 A
0.250 A
-0.250 A
A: r2[i]
20.00ms 35.00ms 50.00ms 65.00ms
150.0 V
50.00 V
-50.00 V
-150.0 V
-250.0 V
A: scr1_1
40.00ms 55.00ms 70.00ms 85.00ms
2.500 V
-2.500 V
-7.500 V
-12.50 V
A: r1_2
Thyristor voltage
Loadcurent
Capacitor voltage
Load
MAC210-6
D1DIODE
+C1
0.9uF
R110k 20%
50 Hz
V1-220/220V
B A
R2100
B A
MAC210-6
D1DIODE
+C1
0.9uF
R110k 20%
50 Hz
V1-220/220V
B A
R2100
35.00ms 50.00ms 65.00ms 80.00ms
200.0 V
100.0 V
0.000 V
-100.0 V
-200.0 V
A: r2_2
Triacvoltage
35.00ms 50.00ms 65.00ms 80.00ms
2.500 A
1.500 A
0.500 A
-0.500 A
-1.500 A
-2.500 A
A: r2[i]
Triaccurrent
35.00ms 50.00ms 65.00ms 80.00ms
1.500 V
0.500 V
-0.500 V
-1.500 V
A: d1_k
Capacitorvoltage
.
S1
0.5uF
2N2646
20V
D
MAC210-6
C
3.00ms
0/0V
B
120 Hz
0/5V
A
50 Hz
15/-15V
AB
QV(A+B)
5k 150
47
20
100
D
C
B
A
6.000ms 8.000ms 10.00ms 12.00ms
5.000 V
3.000 V
1.000 V
-1.000 V
-3.000 V
-5.000 V
A: q1_3
5.000ms 15.00ms 25.00ms 35.00ms
12.50 V
7.500 V
2.500 V
-2.500 V
-7.500 V
-12.50 V
A: q1_2
0.000ms 10.00ms 20.00ms 30.00ms
12.50 V
7.500 V
2.500 V
-2.500 V
-7.500 V
-12.50 V
A: q1_2
0.000ms 10.00ms 20.00ms 30.00ms
12.50 V
7.500 V
2.500 V
-2.500 V
-7.500 V
-12.50 V
A: q1_3
0.000ms 10.00ms 20.00ms 30.00ms
12.50 V
7.500 V
2.500 V
-2.500 V
-7.500 V
-12.50 V
A: q1_3
0.000ms 5.000ms 10.00ms 15.00ms
25.00 V
15.00 V
5.000 V
-5.000 V
-15.00 V
-25.00 V
A: c1_2
UJTneedle
s
Loadvoltag
e
Pulsegenerator
Loadvoltag
e
Capacitorvoltage
Triac firing circuits