The difficulty of solving combined heat and power (CHP) economic dispatch l
ies in the constraints imposed by the multi-objectives. The mutual dependen
cies of heat-power capacity make it hard to find a feasible region, not to
mention the optimum. This paper presents a novel ant colony search algorith
m (ACSA) approach for this problem. The main characteristics of the ACSA ar
e positive feedback, distributed computation and the use of a constructive
greedy heuristic. Positive feedback accounts for the rapid discovery of goo
d solutions, distributed computation avoids premature convergence, and the
greedy heuristic helps to find acceptable solutions in the early stages of
the search process. However, despite the attraction of the ACSA's potential
search ability, there are still some difficulties, such as the handling of
constraints and premature convergence. This paper proposes to couple the A
CSA with other search techniques to improve its performance. The numerical
results reported are encouraging. (C) 1999 Elsevier Science S.A. All rights
reserved.