# Coordinated Dispatch of Multi-Energy Microgrids and Distribution Network with a Flexible Structure
## 5 Simulation Result
### Result Analysis  
#### 5.2.1 First Level  
Table 5 records the daily power loss and voltage offset of the distribution network. The daily power loss and voltage offset in Cases 2 and 3 are significantly lower than those in Case 1. Compared with Case 2, the daily power loss and voltage offset of Case 3 reduces more. It can be seen that under the framework of the coordinated dispatch of the MGs and the DN and, taking the topology of the DN into consideration, the power loss and voltage offset of the distribution network can be effectively \begin{table}
\begin{tabular}{c c c} \hline \hline  & **MGs Optimal Dispatch** & **Operation of DN** & **DN Reconfiguration** \\ \hline Case1 & \(\surd\) & \(\times\) & \(\times\) \\ Case2 & \(\surd\) & \(\surd\) & \(\times\) \\ Case3 & \(\surd\) & \(\surd\) & \(\surd\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Of Different Cases. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameters** & **Values** & **Parameters** & **Values** \\ \hline \(\eta_{WH}\) & 0.8 & \(Q_{\max}^{HX}\) & 2000 kW \\ \(\eta_{GB}\) & 0.9 & \(Q_{\max}^{AC}\) & 1500 kW \\ \(\eta_{HX}\) & 0.9 & \(Q_{\max}^{ECS}\) & 1000 kW \\ COP\({}_{AC}\) & 1.2 & \(P_{\max}^{ESS}\) & 100 kW \\ COP\({}_{EC}\) & 4 & \(P_{dis,\max}^{ECS}\) & 100 kW \\ \(\eta_{ch}/\eta_{dis}\) & 0.96 & \(SOC_{\max}^{ESS}\) & 0.9 \\ \(\delta\) & 0.02 & \(SOC_{\min}^{ESS}\) & 0.2 \\ P\({}_{\max}^{CT}\) & 1500 kW & \(P_{\max}^{sm}\) & 2000 kW \\ Q\({}_{\max}^{GB}\) & 2000 kW & \(P_{\max}^{sm}\) & 1000 kW \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Device Parameters in MGs. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Time Slot** &
\begin{tabular}{c} **Price between DN** \\ **and MGs** \\ \end{tabular} & **Price between** \\ \hline
23:00–7:00 & 0.17 & 0.12 \\
7:00–8:00 & 0.49 & 0.37 \\
17:00–18:00 & 0.83 & 0.65 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Purchasing price of MGs and DN. reduced. Figure 7 illustrates the lowest voltage amplitude of all electrical buses at each time slot in a day. As can be seen from the Figure 7 that in all cases, the lowest voltage is within the limitation. The amplitude of the lowest voltage in Case 2 has the maximum fluctuation value and the voltage reaches lower bound at time slot 1, 6, 20, 22 and 24 compared with Case 1 and Case 3. Combined with data shown in Table 5, although the total voltage offset decreases, the minimum amplitude of voltage in Case 2 is at the risk of exceeding the lower limit at part of the time slots. In Case 3, through the DN reconfiguration, the voltage amplitude offset further reduces. At the same time, the fluctuation of the minimum value of all electrical bus voltage amplitudes reduces and does not fall to the lower limit at each time slot, leaving a certain safety margin. It can be seen that the reconfiguration of the DN can effectively restrain the voltage amplitude from exceeding the limit. which also proves the necessity of distribution network reconfiguration. For Case 3, Figure 8 demonstrates the states of the remote-controlled switches in the DN during the day (red means closed while green means open). By adjusting the states of the branch switch at multiple time slots (1-2, 6-8, 11-12, 18-24), the topology of the DN is guaranteed to be radial and the operating state of the distribution network is optimized to reduce the DN network loss and voltage offset and also improve the condition of power interaction between the DN and the MGs. The power interaction on tie lines between the DN and the three MGs is shown in Figure 9. Figure 9a-c represents the power interaction between the DN and the three MGs in Cases 1-3, respectively. In Case 1, when only optimal dispatch of the MGs is considered, the power interaction between the MGs and the DN is relatively random, which will adversely affect the operation of the DN.