Advanced Power Electronics Based FACTS Controllers: An Overview

With the ever-increasing complexities in power systems across the worldwide, especially opening of electric power markets, it becomes more and more important to provide stable, secure, controlled and high quality electric power on today’s environment. The deregulation and competitive environment in the contemporary power networks will imply a new scenario in terms of load and power flow condition and so causing problems of line transmission capacity. Hence, there is an interest in better utilization of available power system capacities by installing new devices such as Flexible AC Transmission systems. The idea behind the FACTS concept is to enable the transmission system to be an active element in increasing the flexibility of power transfer requirements and in securing stability of integrated power system. In this paper some developed FACTS devices and their control features have been critically reviewed, also highlights some underdeveloped FACTS devices and their controllers, which are under testing and R & D stage.