Impact of SSSC Control Modes on Small Signal Stability and Transient Stability

Abstract

In todays era the demand of electricity has increased and power system has been modernized. So the network of transmission lines interconnecting the generating stations to the main load points becomes complex. In order to carry the high demand of consumers it is required to have stable transmission system. Transient stability improvement is one of the important aspects in modern power system. There is SSSC designed to stabilize the interconnected power system.

SSSC is designed to stabilize the frequency of oscillation in an interconnected power system. As a series compensator, SSSC can control the magnitude of the compensation in two ways, which are called the constant reactance mode and the constant quadrature voltage mode. In the constant reactance mode, the voltage, injected by SSSC, is proportional to the line current. In the constant quadrature voltage mode, the injected voltage of the SSSC is a constant that is in quadrature to the line current.

This study presents the method of improving Voltage and Transient stability of power system using a SSSC. The mathematical model of power system equipped with a SSSC is systematically derived. The presented mathematical model is applied to design control strategy of a SSSC. The simulation results are tested on a Single Machine Innite bus system. The effect of gain control of a SSSC on stability improvement is also investigated.