**ABSTRACT:**

Power
quality improvement is an important issue in power system. Flexible AC
Transmission (FACTS) devices are commonly used for solving problems related to
power quality and improving it. In this paper a synchronous static series
compensator (SSSC) is used for control and modulation of power flow in a
transmission line. The Pulse Width Modulation (PWM) and SVPWM control
techniques are employed in SSSC. The active performance of SSSC is evaluated
using Matlab/Simulink environment. The simulation results validate that the
power quality is enhanced properly using SSSC.

**KEYWORDS:**

1. Power Quality

2. FACTS

3. PWM

4. SVPWM

5. SSSC

**SOFTWARE:**MATLAB/SIMULINK

**BLOCK DIAGRAM:**

Figure
1. Functional model of SSSC.

**EXPECTED SIMULATION RESULTS:**

Figure
2. (a) Source voltage (b) Source current without SSSC.

Figure
3. (a) Load voltage (b) Load current without SSSC.

Figure
4. (a) Source voltage (b) Source current with SSSC.

Figure
5. (a) Load voltage (b) Load current with SSSC.

Figure
6. (a) Source voltage (b) Source current with SVPWM SSSC.

Figure
7. (a) Load voltage (b) Load current with SVPWM SSSC.

Figure
8. FFT analysis of (a) Source voltage (b) Source current-without SSSC.

Figure
9. FFT analysis of (a) Load voltage (b) Load current –without SSSC.

Figure
10. FFT analysis of (a) Source voltage (b) Source current with SSSC.

Figure
11. FFT analysis of (a) Load voltage (b) Load current with SSSC.

Figure
12. FFT analysis of (a) source voltage and (b) source current using SVPWM SSSC.

Figure
13. FFT analysis of (a) Load voltage and (b) Load current using SVPWM SSSC.

**CONCLUSION:**

In
this paper the problem of modulation and control of power flow in transmission
line is carried out by using SSSC with PWM and SVPWM techniques. The
performance of SSSC is validated using Matlab/Simulink software. Thus,
simulation results and THD analysis shows that by using SVPWM based SSSC power
quality gets improved more as compared to the SPWM based SSSC. Hence SVPWM
technique proves better as compared to that of the SPWM technique for power
quality improvement.

**REFERENCES:**

[1]
N.G. Hingorani and L. Gyugyi, “Undеrstanding
FATCS concеpts andtеchnology of flеxiblе ac transmission systеm”,Nеw York, NY:
IЕЕЕ prеss, 2000.

[2]
“Static Synchronous Compensator,” CIGRE, Working group 14.19, 1998.

[3]
Laszlo Gyugyi, Colin D. Schaudеr,
and Kalyan K. Sеn, “static synchronous sеriеs compеnsator: a solid-statе approach to thе sеriеs compеnsation
of transmission linеs”, IЕЕЕ Transactions on powеr dеlivеry, Vol. 12, No. 1,
January 1997.

[4]
Vaishali M. Morе, V.K. Chandrakar, “Powеr
systеm pеrformancеs improvеmеnt by using static synchronous sеriеs compеnsator”,
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Communication and Bio-Informatics 978-1-4673-9745-2©2016 IЕЕЕ.

[5]
M. Farhani, “Damping of subsynchronous oscillations in powеr systеm by using static synchronous sеriеs
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