Unit commitment algorithm considering the effects of economic dispatch

In this paper, a new UC (unit commitment) algorithm is developed with the consideration of ramp constraints and the effects of the ED (economic dispatch). The proposed UC algorithm reduces the generation level of the less efficient units by committing additional units or by the effects of ED, and finally makes the overall system operation cost more economical. This paper also presents a new method of solution refinement considering the excess generation due to the start up and shut down processes. The proposed method is tested with sample systems, which shows that economic dispatch should be incorporated with the UC algorithm at every stage. It should be noted that the unit schedule may considerably depend on the ED and ramp rate limit constraints. The total generation cost can be remarkably reduced as shown in test cases while considering various constraints reflecting the practical system characteristics.