A novel hybrid harmony search and particle swarm optimization method for solving combined heat and power economic dispatch

Combined heat and power (CHP) units are able to generate power and heat, simultaneously. The main objective of CHP economic dispatch (CHPED) problem is to provide optimal heat and power production of cogeneration units with minimum operation cost of supplying heat and power demand. The CHPED problem should be studied considering several operational and electrical equality and inequality constraints consisting of valve-point loading effects of conventional thermal plants, power transmission loss of the system, power and heat capacity production limits of the plants, and heat and power load demand balance. Moreover, heat and power produced by cogeneration plants have bidirectional dependency, which results to complexity of the CHPED problem. In this study, a novel combination of harmony search (HS) algorithm and particle swarm optimization (PSO) method is proposed for the solution of non-convex non-linear CHPED problem. The proposed optimization technique is employed on two large-scale CHP systems for evaluating the performance of the proposed method. The large-scale CHPED problem is solved applying the proposed hybrid method, which demonstrates the effectiveness of the method in terms of operational cost and convergence characteristics.