Analysis of contingencies through the sensitivity factors of the National Interconnected System. A case study in Ecuador

Abstract

This article is based on a simple contingency analysis using sensitivity factors in the IEEE fourteen bus system, and later in the National Interconnected System (SNI) in the Republic of Ecuador. The Ecuadorian network was analysed during the dry season, considering maximum demand, for the year 2018. A reduction in calculation time considered the use of the load flow in direct current. Through the Line Outage Distribution Factors (LODFs), the impact on the redistribution suffered by the transmission lines corresponds to the system when the outage of an element is known. On the other hand, with the matrix of Power Transfer Distribution Factors (PTDFs), the state of the transmission lines is known given a change in the transfer of power from one area to another. With this consideration in mind, energy transfers between the neighbouring countries of Colombia and Peru are evaluated. MatPower was used as an aid to discern the ability of the system under certain conditions for the calculation in percentage of the loadings of the transmission lines, belonging to a fourteen bus system and then in the SNI. Once the simulations were carried out, there were overloads in the front of the contingency in the lines of the system, for which these affectations are considered by the operators of power systems to be able to mitigate their affectation in the network, by making use of the LODF factors. The results of the fourteen bus system with a power transfer of 70 MW, using the factors, showed that two lines were overloaded. On the other hand, the worst scenario in the SNI occurred with the export of 500 MW of energy to Colombia. In this scenario, three lines had overloads 100% greater than their capacity. This sensitivity approach provides the potential for electricity planners and other bodies to increase their ability to take control actions for higher order contingencies.