FACTS technology for reactive power compensation and system control

In the early days of power transmission in the late 19^th century problems like voltage deviation during load changes and power transfer limitation were observed due to reactive power unbalances. Today these problems have even higher impact on reliable and secure power supply in the world of globalisation and privatisation of electrical systems and energy transfer. Fast and highly reliable power electronic devices (thyristor valves) in static Var compensators (SVC) and HVDC applications proved their effectiveness in HV transmission systems to reduce energy transfer limitations. Further development in semiconductors (GTO and IGCT) allowed new power electronic configurations to be introduced to the tasks of power transmission and load flow control. An overview is given on existing shunt and series compensation FACTS devices like SVC, Statcom, UPFC and TCSC/TPSC. In more detail operating characteristics, response times, space requirements, costs etc are discussed for the shunt compensation devices. Future applications based on IGBT devices are discussed.