A NEW THERMAL UNIT COMMITMENT APPROACH USING CONSTRAINT LOGIC PROGRAMMING

The authors propose a constraint logic programming (CLP) algorithm to solve the thermal unit commitment (UC) problem in this paper. The algo rithm combines the characteristics of the logic programming with the c onstraint satisfaction as well as the depth-first branch & bound (B&B) search techniques to provide an efficient and flexible approach to th e UC problem, Through the constraint satisfaction techniques, the cons traints, which consist of the upper bound on the objective value, are propagated as much as possible to actively reduce the search space of the UC problem in a priori way. Consequently, the optimal solution can be acquired in a very early stage. To demonstrate the effectiveness o f the proposed approach, the practical thermal UC problem of Taiwan Po wer (Taipower) 38-unit system over a 24-hour period is solved by the C EP algorithm implemented in CHIP language. The results obtained are co mpared with those from the established methods of the dynamic programm ing (DP), the Lagrangian relaxation (LR) as well as the simulated anne aling (SA).