Probabilistic Operation of Electric Power Systems Considering Environmental Constraint (Part 2)* -Short Term Operation Method-

We report an optimum operation decision method when a system load varies probabilistically and NO_x emission is constrained at every time. We use an energy storage facility for economic operation and environmental constraint. We consider the energy input/output balance of the energy storage facility for the expected value of the system load, but neglect variation from the expected value. When we do not consider the energy input/output balance, discharging energy is assumed to have been stored at a suitable expected load. Meanwhile, when we must consider the energy input/output balance, we repeat infinitesimal increases and decreases of the stored energy in order to decide optimum operation, because the discharged energy depends on the stored energy, and economy depends on the amount of input/output energy, where, we also use the conveixty of operating cost with the variation of input/output energy. A similar repeated method is used for environmental constraint and probability constraint. Because every group of thermal units has each cost curve, the load level at which energy should be stored or discharged is different for each thermal group. Then we attend to incremental fuel cost. The method which optimizes the thermal start-stop pattern is also reported