Hybrid procedure including subtransmission systems and substations for reliability assessment

Pedro J. Martínez-Lacañina, Antonio de la Villa-Jaén, José L. Martínez-Ramos
  • IET Generation Transmission & Distribution, December 2013, the Institution of Engineering and Technology (the IET)
  • DOI: 10.1049/iet-gtd.2012.0748

What is it about?

A new procedure focused on reliability analysis of subtransmission systems supported by the state enumeration technique is presented. This new methodology is conducted in three stages. First, a classical state enumeration reliability assessment is performed for the branch-node model of a subtransmission system, assuming that substations are perfectly reliable. Second, a detailed model of the subtransmission system is considered and the reliability of each substation is assessed by considering them in a ‘one-by-one’ process, supposing perfect operation for the branch-node model. Finally, the reliability indices calculated in the first and second stages are analytically combined to obtain the reliability indices for the subtransmission system (system reliability indices) and for the load nodes of the distribution system (load-node reliability indices). Test results show that the proposed methodology is suitable for both planning studies and 24 h-ahead security assessment.

Why is it important?

This paper focuses on the need to include the configuration of substations in the reliability assessment of meshed subtransmission networks in order to determine, in a first stage, the critical load-points, and to obtain, in a second stage, accurate reliability indices for the critical load-points. The proposed methodology allows to deal with realistic subtransmission systems, including substations’ configuration, with acceptable computational times for short-term reliability assessment.


Professor Pedro Jose Martinez-Lacañina (Author)
Electrical Engineering Department - University of Seville

The advantages of the proposed enumeration technique are, first, determining the correlated impact of failures between substations, that cannot be obtained by traditional reliability studies and, second, the assessment of both subtransmission system’s reliability and substations’ reliability in a faster way than the one performed by traditional reliability studies.

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The following have contributed to this page: Professor Pedro Jose Martinez-Lacañina