## 3 Results
PV systems have an installed capacity expressed in kWp, representing the rate at which they generate the energy at peak performance, such as on a sunny day in the afternoon [50; 51]. Another assumption refers to prosumers who do not have energy storage systems, representing the current situation in Romania. Figures 7 and 8 present the generation profiles of the two PV systems (3 and 5 kWp), m\({}_{\rm EP}^{\rm PV}\) - 2 \(\times\)\(\sigma_{\rm EP}^{\rm PV}\) (low energy production), m\({}_{\rm EP}^{\rm PV}\) (average energy production), and m\({}_{\rm EP}^{\rm PV}\) + 2 \(\times\)\(\sigma_{\rm EP}^{\rm PV}\) (high energy production), determined for June and used in the analysed scenarios. The number of the scenarios (SC) obtained from the combinations between the three indicators is N\({}_{\rm SC}\) = PD \(\times\) CEC \(\times\) EP\({}_{\rm PV}\) = 5 \(\times\) 5 \(\times\) 3 = 75 (see Table 2), to which is added the base scenario (S0), represented by the current situation where PD = 0, CEC = 0, and EP\({}_{\rm PV}\) = 0. The MV side of the EDS represents in our study the slack node used in the steady-state calculations. However, the final results will refer only to the low-voltage part to highlight the impact of the RBES on the active LVEDN. Figure 9 presents the aggregation of the active powers at the LV level (0.4 kV) of the EDS for the analysed day from June associated with scenario S0. The OLTC operates on tap \(\alpha_{\mathrm{s}}=8\) regardless of the time slot s, s = 1,..., 24, in this scenario. The high differences between loads of the three phases can be observed, having an unfavourable effect on the energy losses. This effect is due to the pronounced unbalance degree reflected on the additional circulations in the neutral conductor; see Figure 10.  
The highest energy losses are in the conductor from the phase \(\gamma_{\mathrm{b}}\) (48.4%), followed by neutral (38.5%), phase \(\gamma_{\mathrm{c}}\) (9.6%), and phase \(\gamma_{\mathrm{a}}\) (3.4%). The percentage values have been reported for the total energy losses (77.03 kWh). The energy losses contain only the component associated with the losses in conductors. However, the LVEDNs with the high unbalance degree represents a common feature of the Romanian distribution system. Thus,  
Figure 10: The energy losses in the conductors of the active LVEDN in the analysed period (24 h). Figure 9: The aggregation of the active powers at the LV level (0.4 kV) of the EDS for the analysed day from June associated with scenario S0. the DNO should solve the unbalance issue before integrating prosumers that could cause additional issues, as will be presented in the following. Regarding the voltage quality, all phase voltages at the pillar level have values inside the allowable range [\(-10\%\), \(+10\%\)] according to the European Standard EN 50160 [52], even if the OLTC has a constant tap position, \(\alpha\) = 8. Figure 11 presents the phase voltage variation in the analysed period, where more values are very close to the lower limit value (0.9). In the next step, operating the LVEDN without using the RBES in the OLTC-based voltage control in all scenarios presented in Table 2 was considered. Tables 3 and 4 present the results associated with the minimum and maximum phase voltages and total energy losses obtained after performing the steady-state calculations. The tap position of the OLTC was considered constant, \(\alpha\) = 8, for all time slices, \(s\) = 1,..., S, in all scenarios characterized by the values of PD, EP\({}_{\text{PV}}\), and CEC.