## 4 Results and Discussion
### DCMG Simulated Model Results
Ideally, the wind turbines should supply the system's energy needs during the night to complement photovoltaic generation. Additionally, the voltage on the DC bus exhibits a lower amplitude ripple compared to the first scenario. This reduction may be attributed to the fewer inverters connected to the DC bus in this setup. In order to understand the behavior of the voltage on the DC bus in a more elaborate way, a test was carried out to connect and disconnect loads without producing adjacent energy, i.e., only with the aid of the BESS, as shown in Figures 16 and 17. Changes in the system's load have a direct impact on the voltage level of the DC bus. The BESS adjusts its current output to match the load demand. When power consumption varies, the BESS modifies its current accordingly. During the transition period, when the BESS adjusts its current, a temporary voltage spike or dip may occur. This behavior is directly influenced by the droop control mechanism of the BESS. As the only active power  
Figure 16: Voltage waveform on the DC bus, state of charge and current of the BESS, and consumed power when switching AC loads on and off for three different levels without energy production. Figure 15: Voltage waveform on the DC bus, state of charge of the BESS, and produced and consumed power during the second scenario. source in the system, the BESS uses droop control to compare the DC bus voltage with a reference value (700 V). Based on this comparison, a reference current is determined and applied to the BESS converter to stabilize the voltage. Specifically, an increase in power consumption, caused by activating more loads, results in a voltage drop, while reducing power consumption by switching off loads causes the voltage to rise. The magnitude of these voltage variations is proportional to the degree of change in power consumption. In this scenario, the DC bus voltage remains within the limits specified by IEC TR 63282 [20]. In particular, in island mode, the BESS plays a critical role in maintaining a stable DC bus voltage. However, the system's ability to respond to load variations is constrained by the maximum current capacity of the BESS. In addition to analyzing the effects of varying power consumption, it is equally important to examine the impact of changes in power generation, as these are also directly linked to variations in the DC bus voltage. Figure 18 illustrates the model's behavior under conditions of varying power production while maintaining a constant load of 15 kW. The results reveal that changes in power production have the opposite effect on the DC bus voltage compared to changes in power consumption. Specifically, an increase in power production leads to a rise in voltage, while a decrease in power production results in a voltage drop. For this scenario, the DC bus voltage remains within the limits specified by IEC TR 63282 [20]. As with load variations, the system response to changes in power generation in island mode is constrained by the maximum current capacity of the BESS. Furthermore, the inverse relationship between power consumption and production introduces specific dynamics: when both load demand and power production increase simultaneously, the deviation in DC bus voltage is mitigated. In contrast, when the load demand decreases while power production rises, the deviation in voltage becomes more pronounced. As well as testing the operation of the model in island mode, it is also important to check its stability when connected to the AC distribution network. Figure 19 therefore shows the results of connecting the model to the AC distribution network, with an active load of 18 kW during a time when there is no production and only the BESS supplies energy to the DCMG. When the AC distribution network is initially connected, a voltage drop occurs as the BESS ceases to supply energy. Subsequently, the voltage rises and stabilizes within the recommended limits.