FACTS is a concept introduced by Electric Power Research Institute (EPRI), U.S.A.It is actually a group of advanced transmission technologies that rely on high speed, solid-state electronics, rather than electromechanical devices.
By this concept, the apparent impedance of a transmission line is controlled according to certain algorithm. Thus the power system operation is made more reliable, controllable and efficient. The FACTS system is a promising method, which can be implemented into the system for enhancing system stability by damping out system oscillations.
But in practical applications certain difficulties are encountered while implementing FACTS. This is mainly due to the impact of FACTS on interconnected networks, where for interconnections to serve their purpose, available transmission links must be powerful enough to safely transmit the amounts of power intended.
Also cost structure is another difficulty. It depends on factors like power rating, type of device, system voltage, and system requirements, environmental conditions, regulation requirements etc. In addition to this, the variety of options available for optimum design renders it impossible to give a cost figure for FACTS installation.
FACT system is a promising method, which can be implemented into the system for enhancing system stability by damping out system oscillations. At the heart of FACT are thyristors, which permit control and switching of megawatt levels of power within milliseconds..