Optimum operation Scheduling of Electric Power System Including the Pumping-up Power Stations （Part 5） -Thermal Unit Commitment Decision Method-

In the previous paper, we reported the optimum operation scheduling method which can satisfy the environmental pollution constraint. In a general convenient method, the unit commitment of thermal power stations is decided by the priority method. But the priority method does not always decide the optimum unit commitment, and it may not consider the environmental pollution constraint. In this paper, we decide the unit commitment by the effect of stopping a thermal power station. This effect is calculated through considering the system’s cost increase when one thermal power station is stopped. We have considered the recirculating type pumped storage power plants in our serial papers. In this paper, we consider the other energy storage units, for example, the multiple-use type pumped storage units, superconducting coils, or fly-wheels. Our method is applied to a model system, and we report the results as follows. Our method can estimate the optimum operation which satisfies the environmental pollution constraint. The start and stop pattern of thermal power stations changes depending on the constraint of environmental pollution. We also show the influence of the effiｃｉｅｎｃｙ and the ｅnｖｉｒｏnmental pollution constraint on the total system operating cost