The development of FACTS and its control

A new technology in the field of power system, the flexible AC transmission system (FACTS), is gaining the interest of more and more electrical power technicians in the world due to its enormous advantages. This paper gives a general overview of its development, briefly describes its devices and explains its effects. Furthermore, because of the tremendous influences on the power system by the introduction of FACTS, there is a great demand to improve the power system analysis. Also, this paper presents some aspects and directions needed to be studied.