Line limit preserving power system equivalent

A reduced order equivalent of a power system is a simplified model of the original system with the ability to preserve some key characteristics and to provide adequate fidelity in simulation studies with considerably reduced computational requirements. In this paper, an algorithm to construct an equivalent system with the ability to retain thermal line limits is presented. The application of Kron´s reduction and power transfer distribution factor is used in the creation of the reduced system. The criteria for this method and its step-by-step procedure with the implementation to a small power system are described. Also, the result of its application to the IEEE 118 bus system is provided.