A hybrid differential evolution method for dynamic economic dispatch with valve-point effects

Dynamic economic dispatch (DED) plays an important role in power system operation, which is a complicated nonlinear constrained optimization problem. It has non-smooth and non-convex characteristic when generation unit valve-point effects are taken into account. This paper proposes a novel hybrid method to solve DED problem with valve-point effects, by integrating an improved differential evolution(IDE) with the Shor’s r-algorithm. The proposed method is developed in such a way that IDE is applied as a based level search, which can give a good direction to the optimal global region, and a local search Shor’s r-algorithm is used as a fine tuning to determine the optimal solution at the final. A feasibility-based selection comparison technique and a heuristic rule are devised to handle constraints effectively in IDE, which does not require penalty factors or any extra parameters and can guide the population to the feasible region quickly. The feasibility and effectiveness of the proposed hybrid method is demonstrated for an application example and the test results are compared with those of other methods. It is shown that the proposed method is capable of yielding higher quality solutions.