Security-Constrained Power System Transfer Capability Assessment

Till now, many transfer capability techniques are performed in a simplified manner, with limited consideration of security constraints. This is unacceptable as the risks for not evaluating security impacts are high. There have been doubts on whether current techniques could provide secure transfer capability assessment and thus introducing a new challenge. This paper presents an optimal power flow based (OPF-based) approach for transfer capability assessment incorporating a security index which determines the system security level utilizing various techniques. Line stability indices are also implemented to quantify how ‘close’ the system is to the point of static voltage collapse and to identify the critical lines connecting weak buses in a stressed system. A case study of a 9-bus system is presented to demonstrate the proposed technique.