Amélioration du contrôle topologique de type « Optimal Transmission Switching » en vue d’une utilisation en contexte hydro-électrique à échelle réelle

Abstract

This thesis presents an extended version of the Optimal Transmission Switching (OTS) algorithm along with heuristics allowing it to be used on medium-sized networks. It is first shown that the OTS of the literature tends to weaken the network in terms of voltage stability when several lines are opened. However, it is also shown that there are several topologies that improve the network from an optimization perspective without weakening it, which makes the usage of loadability constraints in the problem formulation possible. Results show that an OTS with such constraints ensures minimum voltage stability while offering good performance in terms of minimization. Then, to make the OTS appropriate in a hydroelectric context, an optimization criterion formed by the weighted sum of operating costs, network losses, and voltage stability is proposed. It is thus shown that the OTS may be used to minimize losses or to maximize loadability as well as to minimize operating costs. Another modification to the problem formulation is then proposed to add control of shunts and series compensations of the network as well as the tap position of variable transformers in the control vector. Results show that these new degrees of freedom allow the algorithm to identify good topologies in situations where classic OTS limited to line state control is unable to do so. Finally, heuristics are developed in order to accelerate the identification of an advantageous topology and thus allow the proposed extended OTS to be used on larger networks. These heuristics are parallelizable and have parameters in order to adjust the performance-resolution time compromise. Consequently, the maximum size of the network on which E-OTS may be used is dictated by the number of available CPU cores. Tests performed with a 28 cores system show that the proposed heuristics identify an improving topology on less than 40 minutes on the PEGASE network (1354 bus & 1991 lines), as well as on the winter peak Polish network (2383 bus & 2896 lines).

Date	21 Sept 2020
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Louis-A. Dessaint (Supervisor) & Innocent Kamwa (Co-supervisor)