Abstract
The task of modelling and locating steady-state unified power-flow controllers (UPFCs) for static voltage stability enhancements in power system planning is addressed. A hybrid UPFC model for power flow studied is proposed. The series side of the UPFC is represented by an ideal voltage source, while the shunt side is represented by an idea current source model. Equivalent relationships among our new models and existing models will also be investigated. Integrations of this hybrid UPFC model into existing Newton-type power-flow solvers are presented. Extensions of continuation methods for locating the voltage collapse point of power systems embedded with UPFCs are studied. Strategies of determining the UPFC rating and locations for voltage stability enhancements will also be discussed. Numerical demonstrations of IEEE 300-bus test system and Taiwan power system are performed to verify the correctness of the proposed UPFC model and the computational tool. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.