Patent ID: 8046111

Claim:
A method of controlling multiple flexible alternating current transmission systems (FACTS), the method comprising: monitoring voltage stability based on data from a supervisory control and data acquisition (SCADA)/emergency management system (EMS) that receives data from a power system and FACTS data from local FACTS controllers; determining whether a margin of the voltage stability is within a reference stability and generating a reference voltage Vref and a reactive power output Qout according to the state of the system through calculation of power and flow voltage, as a control command for changing an operation point of the FACTS, each of which is installed in a substation, if the margin of the voltage stability is within the reference stability; and supplying the reference voltage and the reactive power output to the FACTS controller of each local substation, the FACTS controller of each local substation being operated with the operation point of the FACTS changed depending on the control command by using VQVI index, and the FACTS controller of each local substation providing the FACTS data to the SCADA/EMS.