Overcoming the various steady and dynamic state instabilities of PowerSystems using various FACTS Devices

1. StudyofVariousFACTSDevicesForSteadyAnd
DynamicStateStabilityOfPowerSystem
By-
Abhinav Saxena
Palak Tulsyan
Arunesh Singh

2. Problem discovered-
Instability in static as the well dynamic
state performance of the power systems-
 High total system real power loss.
 High total real power flow PI.
 Increasing voltage deviation.
 Heavy line loading.

3. Literature Survey-
 Genetic Algorithm(GA) to reduce total system real
power loss.
 GA to lower down real power flow performance
index(PI).
 Particle Swarm Optimization (PSO) to bring down
voltage deviation.
 PSO to reduce line loading under overload
conditions.

4. Research Objective-
Optimal allocation of Flexible AC Transmission Systems (FACTS) devices
in power system is observed as significant factor to improve the static as
the well dynamic state performance of the power systems.
FACTS device as Unified Power Flow Controller (UPFC) is placed to
reduce total system real power loss and total real power flow PI. Optimal
placement of Static Var Compensator (SVC) and Thyristor Controlled
Series Compensator (TCSC) are found effective in lowering voltage
deviation and line loading and leading to improved system stability
compared to existing literature.
The effectiveness of different approaches is demonstrated on an IEEE 14
Bus system for the devices as discussed. Simulation results are obtained
and presented for the discussed algorithms.

5. FACTS
UPFC (to reduce total
system real power loss and
PI)
SVC (to improve voltage
deviation)
SVC-TCSC (to control
voltage deviation and line
loading during overload)

6. Research Methodologies
 Generalized Algorithm is studied and used for optimal placement of
UPFC to reduce total system real power loss and PI. Further, the
improved results are compared to existing Genetic Algorithm.
 Standard Evolutionary Algorithm and Adaptive Evolutionary Algorithm
are adopted and compared to existing PSO technique to place SVC to
lower voltage deviation.
 Biogeography Optimization technique is followed to place SVC-TCSC to
control line loadings and voltage deviation during line overload
condition.

7. Experiments conducted on IEEE-14 Bus
System-
Generalized Algorithm
Evolutionary Algorithm
BBO technique

8. I. Generalized Algorithm-
Our motive is to bring down line overload by placing UPFC in
transmission grid maintain the power flow in other lines
under controllable limits. As FACTS devices are not placed at
generation buses despite maximum sensitivity, UPFC is
placed in line-k with least inserted voltage magnitude and
current sensitivity, and in line the absolute value of phase
angle sensitivity is maximum. The efficacy of the generalized
approach method is displayed on IEEE, 14 Bus System.

9. II. Standard EA and Adaptive EA-
Maintaining diversity of evolutionary algorithm, adaptive
evolutionary algorithm is used where every individual of
population is formed by various factors to be controlled.
Generator bus voltage magnitude, reactive power injections
of devices form population vectors. Mutation and crossover
are chosen as parameters for variation. The algorithms run at
the rate of 1,000 generations/iterations taking randomly
created population of 100 individuals. Assuming initial
mutation and crossover rates as 5% and 60% respectively, the
algorithm is executed to generate the results.

10. III. BBO Technique

11. Results-
 The study shows that placement of UPFC according to the proposed
algorithm reduces the total system real power loss by 0.003MW and
brings down line overload PI by a factor of 0.91 as compared to existing
results of GA.
 The laid EA reduced reactive power losses by 20% and voltage
deviation by 90% compared to Particle Swarm Optimization (PSO) to
place SVC.
 Effect of installation of TCSC and SVC on voltage deviation and line
loading is studied under overload conditions, by step by step increasing
load. The result shows, after the device placement the load bus voltage
deviations and line loadings are minimized to a greater extent
compared to existing PSO technique.

12. Conclusion and Future Scope-
This paper present the comparative study of different FACTS devices
mainly UPFC under different IEEE-14 bus for analyzing the static and
dynamic stability of any network under different fault condition. It is
found that FACTS devices have better tendency to trip fault, reduce power
loss, manage line loading and gives smooth voltage at the output with less
harmonic variation which further improves the system reliability. The
load factor variation is acceptable under quite certain range.
If the above concept of stability improvement under different
buses is applied to different intelligence technique, then the
performance can be improved at much quite permissible level under
different fault conditions.

13. References-