1. 1
Sem.:
Sec.:
Course: Content delivered: Date of
delivery:
Faculty:
7th
,
Asec
Power
Electronics
Power electronics circuit
simulation and analysis
MATLAB/Simulink
21st
Aug 2017 Dr. B. G.
Shivaleelavathi
ContentbeyondsyllabusPowerElectronics:
C403.5 Apply computer skills (e.g., PSPICE and MATLAB/Simulink) for the
simulated analysis and design of Power Electronic circuits.
L3
Q. No. Topic COs
1 MATLAB/Simulink SimulationStudy and Analysis of Harmonics Generation in
Uncontrolled and Controlled Rectifier Converters.
(i) Simulate a Full wave bridge uncontrolled rectifier in Simulink for R and RL
load and analyze for harmonic contents in the rectifier output voltage
waveform.
(ii) Simulate an controlled Full wave bridge Fully Controlled Rectifier in
Simulink for R and RL load and analyze for harmonic contents in the
rectifier output voltage waveform.(with and without free wheeling diode).
(iii) Perform a comparative analysis for the above two cases and give your
conclusion.
C403.5
Solution:
Full Wave Diode Rectifier
Continuous
powergui1
v
+
-
Voltage
Measurement1
output voltage1
v
+
-
Voltage
Measurement1
V1
Scope1
RL load1
m
a
k
D8
m
a
k
D7
m
a
k
D6
m
a
k
D5
i
+ -
Current
Measurement1
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
JSS ACADEMY OF TECHNICAL EDUCATION
JSS Campus, Dr. Vishnuvardhana Road, Bengaluru - 560060.
2. 2
Simulink model of Single Phase Full Wave (Uncontrolled) Bridge Rectifier--SPFBR
SPFBRdiode rectifier with RL load
FFT analysis of SPFBR (Diode)with RL Load
0 0.02 0.04 0.06 0.08 0.1
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
3. 3
(ii)Single Phase Controlled Rectifier (using SCR)---SPFBR
Single phase Bridge Contolled Rectifier
Low Inductive Effect
High Inductive Effect
Low inductance with free wheelingHigh inductance with free wheeling
Resistive load
Discrete,
Ts = 5e-006 s.
powergui
v+
-
v
+
-v
+
-
v
+
-
v
+
-
Single phase
Pulse Generator
P1
P2
Subsystem
[P2]
[P1]
[P1]
[P2]
[P2]
[P1]
[P1]
[P2]
[P2]
[P2]
[P1]
[P2] [P1]
[P1]
[P2]
[P2]
[P1]
[P1]
[P2]
[P2]
[P1]
[P1]
m
a
k
m
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
g
a
k
i
+
-
i
+
-
i
+-
i
+-
i
+-
4. 4
(ii)Single Phase Controlled Rectifier (using SCR)---SPFBR
SPFBR with resistive load
FFT analysis of SPFBR with Resistive load
0 0.02 0.04 0.06 0.08 0.1
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
0 200 400 600 800 1000
0
20
40
60
80
100
Frequency (Hz)
Fundamental (100Hz) = 112.7 , THD= 31.88%
Mag(%ofFundamental)
0 0.02 0.04 0.06 0.08 0.1
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
5. 5
SPFBR with resistive inductive(low) load.
FFT SPFBR with resistive inductive(low) load without free wheeling load
0 0.02 0.04 0.06 0.08 0.1
-100
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
0 200 400 600 800 1000
0
20
40
60
80
100
Frequency (Hz)
Fundamental (100Hz) = 127.6 , THD= 47.81%
Mag(%ofFundamental)
0 0.02 0.04 0.06 0.08 0.1
-100
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
6. 6
SPFBR with resistive inductive(high) load.
FFT SPFBR with resistive inductive(high) load without freewheeling diode.
0 0.02 0.04 0.06 0.08 0.1
-100
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
0 200 400 600 800 1000
0
20
40
60
80
100
Frequency (Hz)
Fundamental (100Hz) = 127.6 , THD= 47.80%
Mag(%ofFundamental)
0 0.02 0.04 0.06 0.08 0.1
-100
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
7. 7
SPFBR with resistive inductive(high) load with Freewheeling diode.
SPFBR with resistive inductive(high) load with Freewheeling diode.
SPFBR with resistive inductive(low) load with freewheeling diode.
0 0.02 0.04 0.06 0.08 0.1
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
0 200 400 600 800 1000
0
20
40
60
80
100
Frequency (Hz)
Fundamental (100Hz) = 112.9 , THD= 32.02%
Mag(%ofFundamental)
0 0.02 0.04 0.06 0.08 0.1
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
8. 8
FFT SPFBR with resistive inductive(low) load with freewheeling diode.
0 0.02 0.04 0.06 0.08 0.1
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
0 200 400 600 800 1000
0
20
40
60
80
100
Frequency (Hz)
Fundamental (100Hz) = 112.9 , THD= 32.04%
Mag(%ofFundamental)
0 0.02 0.04 0.06 0.08 0.1
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
9. 9
Conclusion: The above simulation results are tabulated as below:
SPFBR
diode
uncontrolled
RL
α = 00
SPFBR
Controlled
R
α = 300
SPFBR
Controlled.
α = 300
RL (Low)
Without
FWD
SPFBR
Controlled
α = 300
RL(Low)
with
FWD
SPFBR
Controlled
α = 300
RL(High)
without
FWD
SPFBR
Controlled
α = 300
RL(High)
with
FWD
Vodc 144.8volts 135.9volts 126volts 135.7volts 126.7volts 135.6volts
THD 22.73 31.88 47.81 32.04 47.81 32.04
From the above comparative table we conclude:
In fully controlled rectifier the DC output voltage reduces with RL Load. And THD also increases.
Fully controlled rectifier the sue of Free Wheeling Diode (FWD) increases the DC output voltage and
also reduces the Total Harmonic Distortion (THD). And the DC output voltage and THD are same as
Resistive load.
Note: the firing angle can be set in the single phase pulse generator system block.
α(Alpha) can be varied from 0o
to 180o
.
SPFBR with Resistive / RL load with Firing
angle alpha = 0o
, Vodc = 145.6, THD=22.72
0 0.02 0.04 0.06 0.08 0.1
0
100
200
Selected signal: 10 cycles. FFT window (in red): 10 cycles
Time (s)
