Multi-period, Multi-contingency and Interval Optimal Power Flow for Dimensioning and Allocation of Spinning Reserve

Abstract Due to their low environmental impact and decreasing costs, there has been significant growth in the use of renewable sources worldwide. However, their power generation fluctuates randomly, necessitating reliable energy supply methods. Spinning reserve can mitigate the risk of energy deficits during generation interruptions and line contingencies. It is therefore necessary to develop specific techniques for dispatching and scheduling energy, power and reserve, with a focus on attending to emergency situations, congestion of transmission lines and spinning reserve. In this context, the present work proposes a linear multi-period, multi-contingency and interval optimal power flow scheme, which can schedule the power dispatch of a hydrothermal system (including electrical and energetic restrictions) for a horizon of one day ahead, and is also capable of dimensioning and allocating the amounts of spinning reserve necessary to supply different situations involving the outflow of lines and balancing levels of renewable energy not supplied. In addition, as a strategy to incorporate the uncertainties inherent in the problem, interval mathematics is applied to the post-optimization problem; that is, after the deterministic optimization obtained based on the optimal power flow, ranges of uncertainties are added to some network parameters so that an optimal range of network operation can be determined. Results are presented for a system of 291 buses representing the south-southeast network of Brazil. The proposed methodology adequately sizes and allocates the necessary reserve to meet the most important contingencies affecting transmission.