A New Model to Incorporate Unified Power Flow Controllers in Power Flow Studies

The controlled power flow in electric power systems is one of the crucial factors affecting the overall development of modern power systems. The unified power flow controller (UPFC), with its unique combination of fast shunt and series compensation, is a powerful device which can provide both active and reactive power regulation, i.e. voltage magnitude and phase control. In this paper, a new UPFC steady-state model is presented. The main characteristics of the model are that it is easily incorporated in existing load flow software, provides automatic UPFC parameter adjustment and accounts for UPFC operating limits. Details of its concept, implementation and validation against other relevant published results are given. A case-study is presented with the aim of showing the behavior of the device model when operating limits are attained