*5.1. Case Study A*

For this case study, three different active power values are set as references during the day:


The test is developed for day one and two, and the results are illustrated in Figure 21. For any of the days tested, the control of active power makes possible to keep the power reserve equal to 20% of the maximum power capacity for active power higher than 0.20 p.u. When the generated active power is lower than 0.2 p.u, the power reserve is not reached and instead is equal to the maximum possible.

**Figure 21.** Control of active power for different power references. (**a**) Day one, (**b**) Day two.

However, in the case of power curtailment, there are some differences between the first and the second day. In day 1, the active power reference is reached easily with the control due to the sufficient solar irradiance. On day 2, however, the new reference of power is only reached during ten minutes in the morning and eighty minutes in the afternoon. This behavior is because of the drastic changes of solar irradiance during the day.

The deactivation of the power curtailment in order to ge<sup>t</sup> the maximum power during ten minutes is successful in day 1 and day 2. It is important to notice that due to the MPPT control, the ramp rate to ge<sup>t</sup> the maximum power is 0.05 MW/min on day 1 and 0.026 MW/min on day 2.
