flexible ac transmission systems; phasor measurement unit; power system control; Wide area control systems; wide area monitoring systems Control systems; Control theory; Electric power systems; Electric power transmission; Flexible AC transmission systems; Monitoring; Phase measurement; Phasor measurement units; Power electronics; Units of measurement; Wide area networks; Control objectives; FACTS controller; Flexible ac transmission system (FACTS); Phasor measurement unit (PMUs); Power system controls; State of the art; Wide area control; Wide area monitoring system; Electric power system control