Transient stability improvement by FACTS devices: A Comparison between STATCOM and SSSC in an extra high voltage transmission system

Abstract

Loss of 500 kV A-B transmission line causes voltage instability in surrounding subsystem. This condition may cause further disturbance in the whole interconnected system. Improvement of voltage stability can be handled by adding FACTS devices, such as Static Synchronous Series Compensator (SSSC) and Static Synchronous Compensator (STATCOM). SSSC and STATCOM have the capability of dynamically controlling the power flow through a line. This paper aims to compare the performance of both devices to increase system stability. These methods are compared by analyzing the bus voltage, active power in line and rotor angle. As a result, this paper shows that the implementation of STATCOM is more stable in state of SSSC.