Improvement the voltage stability margin of Iraqi power system using the optimal values of FACTS devices

The detection of potential voltage collapse in power systems is essential to maintain the stability heavy load demand. This paper proposes a method detect weak buses using two indices: margin factor (dS/dY) and prediction index (VCPI). Hence, aims improve Iraqi transmission grid by allocating FACTS devices optimal locations sizes. Two types are used this which Thyristor controlled series compensator (TCSC) static var (SVC). objective function problem fitted particle swarm optimization (PSO). proposed verified simulation test on Diyala-132 kV network part system. results observed that improvement margin, profile increased losses decreased.