# A Comparison of Energy Management System for a DC Microgrid
## 4 Results  
The results obtained numerically through a simulation carried out with a test microgrid, which is integrated by a photovoltaic system (PV), storage system (S) and the load (L). The data that were used for the test microgrid are real and also with these data the global irradiance on an arbitrarily oriented and inclined surface was calculated, a global irradiance profile of Cancun city (Mexico) and Baglan (Wales, UK) to make the comparison of the energy generation of the photovoltaic solar system for two different places in the world. The load profile used is the real data obtained from the Baglan Energy Park, Port Talbot, United Kingdom. The results present the numerical values of the geometric model of solar radiation from the two cities mentioned above. It also presents the results of the behavior of the photovoltaic solar system and the storage system within the microgrid resolved through hybrid IP-GA method and PSO method, the methods to solve the optimization problem is determined in a PC DELL, with 8 GB RAM and an Intel i5-4210U CPU@ 2.40 GHz processor. The characteristics of the computer directly influence the speed in which the optimization algorithm can be solved. In this work, solar radiation data from two different places in the world are compared to verify the behavior of the EMS considering the solar resource of each place evaluated. The load profile is based on a relatively small (64 m\({}^{2}\)) two store office block, which in fact forms part of a facility called the Hydrogen Center (University of Glamorgan at Baglan Energy Park, Port Talbot, United Kingdom). The microgrid test is shown in Figure 4. The values of the parameters of the different models of the microgrid are presented in Appendix A. Comparative load and irradiation profile for a clear day (summer) for both cities are observed in Figure 5. The power and voltage bases were selected in 10 kW and 24 V, respectively. Figure 4: Microgrid test scheme. Figure 5: Forecasting curves to the microgrid test. The limits of the magnitudes of the microgrid are \(0.92\leq V\leq 1.05\) per unit. The SOC limits on the battery are \(0.2\leq soc_{S}(t_{i})\leq 1\) (%), whilst the initial condition of the battery charge is \(soc_{S}(t_{0})=0.6\) (%). The EMS was developed with the genetic algorithm method with interior point hybrid (_IP-GA_) provided by the ga-fmincon function developed by MATLAB(r). Figure 6 shows the comparison of the active power supplied by the photovoltaic panel and the battery for the two solar radiation conditions of a clean summer day in Cancun and Baglan. This figure shows that between the stages 8-20 h a demand profile is presented in the office block. In the demand that ranges between 1 and 6 KW, it is observed that the demand peaks occur at 9:30, 11:30, 13, 15 and 17 h.  
The power supplies by the photovoltaic panel are not enough to supply the load demand, making it necessary to use the energy stored in the batteries to satisfy the load demand and avoid problems within the microgrid. It can be observed, that the batteries take advantage of charging at times where the demand for the charge is minimal, such as in 9, 11, 12:30, 14, 15:45 and 17 h. This way it is possible to verify that the EMS algorithm works correctly. Furthermore, it was also observed from the two generation curves of the photovoltaic panel where the generation curve for the Cancun city shows a greater amount of energy than the Baglan city curve, due to the geographical position of each city. Figure 6 indicates the active power supplied by the batteries. It is important to understand that the energy supplied by the batteries in the region of Cancun is less than that supplied in Baglan and it can also be seen that the batteries are charged with more energy in the city of Cancun since in this city the photovoltaic panel produces more energy for the largest amount of solar resources in the region. Figure 7 shows the SOC of the battery in yellow for the city of Baglan and in red the behavior in the city of Cancun.