  This paper presents a solver-friendly logic-based mixed-integer nonlinear
programming model (LB-MINLP) to solve economic dispatch (ED) problems
considering disjoint operating zones and valve-point effects. A simultaneous
consideration of transmission losses and logical constraints in ED problems
causes difficulties either in the linearization procedure, or in handling via
heuristic-based approaches, and this may result in outcome violation. The
non-smooth terms can make the situation even worse. On the other hand,
non-convex nonlinear models with logical constraints are not solvable using the
existing nonlinear commercial solvers. In order to explain and remedy these
shortcomings, we proposed a novel recasting strategy to overcome the hurdle of
solving such complicated problems with the aid of the existing nonlinear
solvers. The proposed model can facilitate the pre-solving and probing
techniques of the commercial solvers by recasting the logical constraints into
the mixed-integer terms of the objective function. It consequently results in a
higher accuracy of the model and better computational efficiency. The acquired
results demonstrated that the LB-MINLP model, compared to the existing
(heuristic-based and solver-based) models in the literature, can easily handle
the non-smooth and nonlinear terms and achieve an optimal solution much faster
and without any outcome violation.
