The rate of Iraqi power demand has been increased significantly faster than the infrastructures development and it becomes very difficult to keep the system stable especially with the current acts of vandalism against the country, so its very important to improve the power system stability. The object of this work is to improve the stability of the Iraqi National Super Grid System (INSGS) by installing Unified Power Flow Controller (UPFC) devices in different optimal locations under fault condition and comparing the results with those of without UPFC devices under the same condition. The...