Network‐constrained hydrothermal unit commitment using benders and optimality condition decompositions.

This paper presents a new network‐constrained hydrothermal unit commitment (NCHTUC) model that considers nonlinear hydro generation functions and AC power flow constraints. In addition, the proposed NCHTUC includes dynamic water balance equations of cascaded hydro plants. To cope with the large‐scale and mixed‐integer nonlinear nature of the model, a new hybrid computational strategy consisting of generalized Benders decomposition and optimality condition decomposition is proposed. By using this method, the NCHTUC problem is decomposed into a master problem, a hydro plant subproblem, and a thermal plant subproblem with independent OPF (optimal power flow) solutions for each time period. In order to verify the effectiveness of the proposed model and decomposition strategy, numerical tests are performed on three test systems of up to 703 buses over a 24‐h horizon. Test results indicate that the developed methodology has excellent convergence and is capable of solving large‐scale NCHTUC problems without loss of accuracy. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]