## 4 Simulation Results
### Simulation Setup
By limiting the total amount of discharging power of EVs at each time interval depending on the difference between local load demand and PV power production, the parked EVs can be charged to the target SOC within the parking time, preventing the excessive discharge of EVs. Through the power management of the MG with the EV charging/discharging scheduling strategy, the discharging power of parked EVs can be used effectively for the local load demand and charging demand of EVs as shown in Figure 12a,b. Due to high charging demand of EVs over the time interval 3:00-8:00, the discharging of EVs is highly activated for the power management of the MG. Furthermore, over the time interval 10:00-12:00 which corresponds to the high peak periods, the discharging power from parked EVs is highly utilized for the local load demand and charging demand of EVs simultaneously depending on the EV charging/discharging scheduling algorithm achieving energy-efficient and economical operation of the PV-based charging station. Though the small amount of discharging power of EVs is available between 12:00 and 17:00, the discharging power of EVs is mainly used for the local load demand to reduce the grid power consumption at high peak periods and decrease the operating cost of the PV-based charging station by selling the power to electric company. With the \"Proposed EV Ch/Dch Scheduling\" and \"EV Ch/Dch Scheduling\" schemes, the operating cost of the PV-based charging station can be minimized by charging and discharging multiple EVs over the time interval 18:00-24:00 which has high SMP while satisfying the charging requirements of parked EVs. In Figure 11a, despite the high electricity cost of grid power consumption between 15:00-17:00, larger charging demand of EVs is shown in the \"Proposed EV Ch/Dch Scheduling\" scheme. With this  
Figure 10: (**a**) The PV power consumption for local load demand; (**b**) The PV power consumption for charging demand of EVs. larger charging demand of EVs in the \"Proposed EV Ch/Dch Scheduling\" scheme, more discharging power of EVs can be efficiently used to supplement the local load demand and charging demand of EVs over the time interval 17:00-24:00. Depending on the proposed EV discharging condition considering the future trends of local load demand and PV power production, the discharging of parked EVs is utilized earlier in the \"Proposed EV Ch/Dch Scheduling\" scheme than in the \"EV Ch/Dch Scheduling\" scheme around 17:00. Figure 12(a),b describe variation of the sum of remaining parking time of EVs to be charged and discharged, respectively, according to different power management schemes. To utilize parked EVs as ESS for the power management of the MG and satisfy the charging requirements of EVs within predetermined parking time of each EV, (22) is provided in the multi-objective optimization. According to (22), parked EVs with less remaining parking time are likely to be allocated to charging operation, and parked EVs with more remaining parking time are likely to be allocated to discharging operation. With the \"EV Ch Scheduling\" scheme, a low sum of remaining parking time of parked EVs to be charged is shown over the time interval 2:00-9:00, which represents that a small number of EVs are charged without EVs to be discharged. Compared with the \"EV Ch Scheduling\" scheme, the \"Proposed EV Ch/Dch Scheduling\" and \"EV Ch/Dch Scheduling\" schemes have higher sum of remaining parking time of EVs to be charged because the discharging power from several EVs is directly supplemented to charging demand of EVs. In Figure 12(b), it is observed that relatively more EVs are used for power management over the time interval 0:00-8:00, 10:00-12:00, and 18:00-24:00 in which discharging of EVs is highly activated  
Figure 11: (a) The charging demand of parked EVs; (b) the discharging demand of parked EVs. Figure 12: (a) The discharging power of parked EVs used for local load demand; (b) the discharging power of EVs used for charging demand of EVs.