Including the Constraints That Have Less Than One-Hour Characteristcis in an Hourly Based Generation Scheduling Regime

For many years, optimal operation of the power system attracts the attention of the researchers. Unit commitment problem (UC) is solved in an hourly basis in many power systems. Although some generation units' specifications require considering less than one-hour steps in scheduling regime, data accusation infrastructures, software capabilities, and personnel limitations may prevent the power system to solve and implement the UC with less than one-hour steps. For instance, a gas turbine generation unit requires less than one-hour to achieve the minimum power level. From the technical point of view, the slopes of ramping constraints are different in the starting up (shutting down) times compared to the normal operating condition. In this paper, the slope of unit ramp rates in shutting down times are called the less than one-hour constraints (LOHC). For an hourly based unit commitment scheduling regime, the LOHC modeling method is proposed and the constraint linearization technique is presented. It is concluded that considering the LOHC not only decreases the value of the objective function, but also increases the functionality of the day-ahead schedule in the real time operation.