I- INTRODUCTION

II- CONTROL BLOCK DIAGRAMS OF SSSC, TCSC AND POD.

III- SIMULATION MODEL

IV- RESULT AND DISCUSSION

V- CONCLUSION

VI- REFRENCES

Abstract

With the growing power demand, it is vital to expand power transfer capacity of transmission lines. But the new expansion in our present transmission system is confined due to financial problems, environmental concerns and health hazards due to electric and magnetic fields. May be its worthwhile option to use flexible AC transmission system (FACTS) for enhancement of power capacity of transmission system. This paper presents, fruitfulness FACTS devices SSSC and TCSC with POD (Power oscillation damper) as additional controller. The major function is to decrease the peaks overshooting and clearing time of inter area oscillations, hence betterment in transient stability. For the fulfillment of analysis, time domain simulation outcomes are correlated for results verification. In addition, the parallel operation of SSSC for the system has been analyzed. This paper proposes modeling and simulation on MATLAB/Simulink Software for the proposed test system. Result displays that, power oscillation are rapidly damped than traditionally PSS by employing POD with FACTS-Controllers.

Introduction

In present-day world, electrical power demand is increasing significantly over the last few decades. After all this growing rate of power demand does not pursue through the enrichment in power generating plants and transmission capacity. Thus in place of, to accommodate the increasing electric load requirement, power generation plants are operating at their maximum capacity[1]. Similarly transmission lines are also running nearer to their thermal limits. So, the power systems are seemly less sheltered and always carrying the exposure of voltage instability which has led to many major network collapses world-wide[2]. As the electric power system was not so complicated in previous times, the major controversy was to damping the local area oscillations which were simply performed by the aid of AVRs[3].Then PSS appear which associated to the generators which present sizable concurrence towards the oscillations of the network. Hence traditionally PSS was employed for damping the local zones of oscillations in electric network[4],[5]. Different preventive measures as generation and transmission of energy adjourn, carrying reserve generators online, load curtailing and VAR back up by serial or parallel capacitors are followed to conquered voltage instability controversy. However, most of them are electromechanical controller which got the demerits like sluggishness, wear and tear[6]. As an alternate key, intense consideration have been compensated to FACTS (Flexible Alternating Current Transmission System) devices which are directed from present-day components of power electronics, which could give active and reactive power accurately and keep the network stability limit[7]. In present paper FACTS devices with additional controller is employed for damping the power network oscillations. Thus by employing POD-FACTS the network power oscillations can be quickly damped as related with another commonly devices[8]. Since these controllers impact the driving voltage and thus the current and flow of power directly. For a given MVA size series controllers are manifolds robust than shunt controllers, in order to perform the desire functions such as to control the current/power flow and damping the oscillations[9].