A Two-Stage strategy to handle equality constraints in ABC-based power economic dispatch problems

Abstract

Power economic dispatch (ED) plays an important role in energy saving in power system operations. The penalty function method is widely used to handle equality constraints involved in ED problems. However, it is sometimes difficult to select the optimal penalty coefficients. To solve this problem, a Two-Stage strategy is proposed in this paper to handle equality constraints in artificial bee colony algorithm (ABC)-based ED problems, called as TSABC. Two groups of onlooker bees are employed in the first stage to search for feasible solutions satisfying all constraints. Then, in the second stage, a novel searching strategy with dynamic bounds for the elements of the solutions is introduced to keep the constraints always satisfied during the optimization process. The TSABC method does not require more control parameters and is easy to implement. Both based on basic ABC algorithm, the Two-Stage strategy is compared with the penalty function method (PFABC) for handling equality constraints in both static and dynamic economic dispatch problems. The comparative analysis reveals that the proposed TSABC method has merit in terms of effectiveness, reliability and solution quality.