Diversity control approach to ant colony optimization for unit commitment problem

This paper presents a new method to solve the constrained unit commitment problem by applying ant colony optimization (ACO) based on the diversity control approach. The pheromone updating rule is modified to control the diversification by adopting a simple mechanism for random selection in ACO. The proposed method is tested on the 10-unit test system with a scheduling time horizon of 24 hours. The numerical results show an economical saving in the total operating cost when compared to the previous literature results. Moreover, two types of the proposed diversity control technique have the features of easy implementation and a better convergence rate superior to a standard ACO.

1. INTRODUCTION

Unit Commitment (UC) problem is to determine most economical start-up and shutdown times for the electrical power generating units to meet a load demand while satisfying a set of operational constraints. The UC problem is a large and complex mathematical optimization with both integer and continuous variables. The exact solution to the problem can be obtained only by complete enumeration, which cannot be applied to realistic power system due to its excessive computation time requirement [1].