A New Formulation for Load Flow Solution of Power Systems With Series FACTS Devices

this paper addresses the solution of load flow equa-tions for a power system with series flexible ac - transmission systems(FACTS) devices. A novel formulation of equations using dual state variables (current magnitude and angle) and dual controlvariables (series injected real power and series voltage in quadra-ture with current) for series devices is proposed. These specifica-tions can be related to transmission line loading and device limits.Specifications like power flow through a series device can also be handled using this formulation. The load flow equations are solved using Newton-Raphson technique. A decoupled formulation is also proposed. Case studies are carried out on IEEE test systems withseveral types of specifications to validate the method