A Monte Carlo technique for setting operating reserve margins under network constraints

The evaluation of the necessary amount of operating reserve in a multi-area electric network has been traditionally carried out by the System Operators on a deterministic basis, using the so called "first contingency security criterion". As an alternative, this paper proposes the use of a probabilistic approach, based on a Sequential Monte Carlo technique. Assuming as an input the production and consumption profiles scheduled by the energy markets, a software realized on purpose by the authors simulates the real time operation of a deregulated electric system in normal, contingency and emergency conditions, drawing outages of components (generating units and main power lines) and unexpected variations of load. Such a technique can be suitably used to evaluate the system reliability as a function of operating reserve margins of generation park, as well as to calibrate the real time dispatching rules and the emergency procedures of the System Operator. The results of a daily case study, basically calibrated on the Italian electric system at its yearly peak, are shown and discussed.