An efficient security assessment in a large interconnected electricity network

In this paper, we propose an advanced methodology for security assessment, which is efficient and applicable to a large interconnected competitive electricity network. We newly propose a mathematical and practical method of assessment of security limits, which is incorporated with a previously presented distributed scheme, to determine the inter-regional maximum secure transfer capability. The power system security of network interconnections which join the adjacent regions should be taken into account in determination of the transfer capability, that is, inter-regional interchange of power should be traded based on the secure transfer capability between adjacent region not on the transmission capacity limit itself, because power system security is one of the major components that support viability of the competitive market. Mathematical description on security assessment is given, followed by a case study for the 3-region IEEE 24-bus reliability test system.