Operating reserve determination and its influence on the operating costs of interconnected power systems

Abstract

A methodology to carry out reliability studies to compute operating reserve requirements of interconnected systems is formulated. This paper shows the application of developments carried out at ‘Instituto de Energía Eléctrica’ in order to calculate the operating reserve requirements, their composition in relation to the access times of different kinds of reserve, and the influence that equipment variations will have on the electric power system operation costs. The calculation of power interchange between areas is performed with a stochastic model of the system. In this model the different levels of assistance capacity of each area are associated with their occurrence probabilities. Covering of own demand has priority. Interconnecting lines between areas are modeled by probabilities associated with their possible states. This methodology allows adequate consideration of operating conditions in power systems planning. System optimal operation costs are calculated under the constraint that there is sufficient operating reserve (stand-by plus spinning reserve) to guarantee a given reliability level. The main aim of this work was the application of this methodology to the Sistema Nacional Interconectado Argentino (Argentine National Interconnected System) for assessing a first approach to operating reserve composition and requirements. In addition, the influence on the operating costs of including a pumped storage power plant located in the province of Buenos Aires is evaluated.