3.1.3. Step 3. Wind Power Absorbed and Curtailed

After the definition of conventional units commitment, the absorbed *PWabs* and curtailed *PWcurt* wind energy are calculated. The wind power allowed to be absorbed by the system is limited by technical restrictions, in order to ensure the stability of the system. A percentage of instantaneous penetration δ of wind power to the grid is applied in the calculations [35,36]. This is a dynamic limit which ensures the safe operation of the system in case that all the wind power is lost, and it is related with the ability of other units (i.e., conventional, hydro and storage) to supply load demand [36]. On the other hand, wind power absorption should respect the technical minimums of the committed conventional power plants [35]. Technical minimums of lignite, natural gas, CHP and biomass are taken into consideration. These two technical restrictions are related with power system and define the ability of the power system to absorb wind power. Finally, the actual wind power absorbed *PWabs* cannot exceed the available wind power *<sup>P</sup>Wprod* , as it has been calculated using the mesoscale data. Then, the actual absorbed wind energy is resulted (Equation (2)):

$$P\_{W\_{abc}(i)} = \min \left\{ \begin{array}{c} \delta \cdot P\_{D-PV(i)} \\ P\_{D-PV(i)} - P\_{TM(i)} \\ P\_{W\_{prod}(i)} \end{array} \right\} \tag{2}$$

Meanwhile, the wind energy curtailment is calculated (Equation (3)):

$$P\_{W\_{curt}(i)} = P\_{W\_{prod}(i)} - P\_{W\_{abs}(i)} \tag{3}$$
