Decoupled power exchange model of UPFC to enhance voltage stability margin of power systems

This paper proposes a novel model of unified power flow controller (UPFC) for enhancing voltage stability margin of the power systems. This model is based upon an innovative approach where, real power exchange of series and shunt elements of UPFC are decoupled with each other. The UPFC model is incorporated into an existing Newton-Raphson load flow algorithm and Jacobian matrix is modified to include the decoupled modes of power exchange of series and shunt elements of UPFC. The modeling approach presented in this paper is tested on standard IEEE 30-bus and IEEE 118-bus systems to validate its feasibility.