Profit based unit commitment for GENCOs using Lagrange Relaxation-Differential Evolution

In the real time operation of power markets under deregulation, electricity price forecasting, profit based unit commitment (PBUC) and optimal bidding strategy are important problems. Among these, the PBUC problem is one of the important combinatorial optimization problems. The objective of generating companies (GENCOs) is to maximize their profit. In this article, a hybrid Lagrange Relaxation (LR)-Differential Evolution (DE) is proposed for solving the PBUC problem. In the proposed hybrid method, the LR is applied to solve the unit commitment problem and the DE algorithm is used to update the Lagrange multipliers. At each stage, secant method is used to solve economic dispatch (ED) problem. The proposed method is tested on 3-units, 10-units and 20-units systems. The simulation results are compared with existing methods available in the literature. The results demonstrate the superiority of the present method over the previous methods in terms of profit and computational time.