## 4 Simulation and Results
### Case A  
The six-bus system shown in Figure 6 is studied over the 24-h of operation. It includes three conventional generators: G1, G2, and G3. A CCHP plant, a P2H/G2P plant, a wind turbine, and an EV charging unit are all located on Bus 4. Parameters of them are listed in Tables 1-3. Consider the maximum and minimum capacity of the hydrogen storage are 200 MWh and 40 MWh respectively, and its initial storage level is 80 MWh [12]. Assume the efficiency for P2H and G2P processes are 80% and 40%, respectively. The hourly electric demand, EV charging demand, forecasted wind power (with 200 MW installed capacity), and ME demands over the 24-h horizon are listed in Figure 7. The gas price is 3.71 $/MBtu for the CCHP production, and the selling price of electricity is 51.22 $/MWh (23:00-7:00), 73.27 $/MWh (10:00-17:00 and 21:00-23:00), and 85.04 $/MWh (9:00-10:00 and 18:00-20:00). Consider the separate generation efficiencies  
In Figure 9, when the wind power is abundant, the generation of the ME demands mainly depends on the free wind power. For instance, in Figure 9b, \(\mathbf{W_{\mathrm{i}}}\) peaks during 8:00-21:00. When the forecasted wind power slumps at 20:00, the production of the CCHP plant turns to rely on the natural gas input, especially when some generators are offline. For instance, at 23:00, only G1 is online, and at 24:00, 1:00, only G1 and G3 are online. In these periods, CCHP plant generates more electricity on purpose to feedback the electric networks. In Figure 10, the P2H/G2P plant operates in P2H mode at 3:00, 7:00-8:00, 15:00, 17:00, 20:00-21:00 and 23:00. Among them, at 3:00 and 15:00, the wind power is abundant, though the conventional generators' outputs are relatively low, the total power supply is enough for the electric demand and P2H process; At 7:00, 17:00, the electric demands reach peaks, but the wind power and generator outputs peak as well, extra power are then stored in hydrogen tank for the G2P process in the following hours. The P2H/G2P plant operates in G2P mode at 1:00, 4:00, 9:00, 16:00, 18:00, and 22:00. At 1:00, 4:00, and 22:00, the outputs of generators are relatively low; at 9:00, 16:00, and 18:00, electric load reach peaks, while the generators' outputs and wind turbine outputs are relatively low. Electricity that are pre-stored in hydrogen tank then released to cope with the power shortage. Figure 8: Dispatch result in Case 1. Figure 9: Dispatch result in Case 2. (**a**) Outputs of conventional generators and the wind turbine. (**b**) Input and output of the CCHP plan. In Figure 11, at 5:00, 8:00, and 11:00, the electric demand is high while the power supply is relatively low, thus the increase in price could effectively decrease the EV charging loads in these periods. At 3:00 and 9:00, the power supply is abundant while the electric load is relatively low, thus the decrease in charging price could encourage consumers' charging behaviors in these periods, which not only saves them more money, but also alleviate the power congestion. So are at 7:00, 12:00, and 15:00, in these periods, though the electric demands are high, there is still a lot of power left. TOU pricing scheme is helpful in guiding EV users to make better charging plans that both benefit themselves and the energy system. Figure 11: Dispatch result in Case 4. (**a**) Outputs of conventional generators and the wind turbine. (**b**) Price deviation for EV charging. Figure 10: Dispatch result in Case 3. (**a**) Outputs of conventional generators and the wind turbine. (**b**) Output of the P2H/G2P plant. Figure 12 shows the obtained dispatch schemes for Case 5 and Case 6. Figure 13 gives the RES utilization rates of the six obtained dispatch strategies, and their corresponding economic and energy saving performances as well. Figure 12: Dispatch result in Case 5 and Case 6. (**a**) Outputs of conventional generators and the wind turbine. (**b**) Price deviation for EV charging. (**c**) Input and output of CCHP plant in Case 5. (**d**) Input and output of CCHP plant in Case 6.