## 4 Simulation Results
### Error Analysis  
To investigate the reliability of the study distribution system, errors are considered in different parts of the system. For this purpose, assuming that the fault location is detected  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Microgrid** & **Place \(DG\)** & **Type \(DG\)** & **Size \(DG\)** & **Source Location \(Q\)** & **Source Size \(Q\)** \\ \hline
1 & \(2,5,6,7,15\) & \(WT,PV,WT,FC,FC\) & 473, 387, 498, 428, 592, 445 & 8, 2 (FC),16 (FC) & 387, 399, 386 \\ \hline
2 & \(16,24,26,31,34\) & \(FC,WT,FC,FC,WT\) & 427, 489, 433, 429, 459 & 17 (FC), 27 (FC), 33 (FC), 34 & 400,395,376,310 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Specifications of resources installed in the network by kVAr and kW.  
Figure 10: Network zoning into 2 microgrids in the third scenario. Which each zone in separated with different colors.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Microgrids** & \(ENS_{P}\) & \(ENS_{Q}\) & \(EVS_{P}\) & \(EVS_{Q}\) \\ \hline
1 & \(16/52\) & \(24/23\) & \(175/57\) & \(30/36\) \\ \hline
2 & \(55/83\) & \(8/89\) & \(56/23\) & \(8/19\) \\ \hline \hline \end{tabular}
\end{table}
Table 8: Expected unmet energy supply (in terms of MWh and MVArh ) due to lack of active and reactive power.  
in the ground state where the network is not zoned, the downstream fault network is separated so that the fault-free parts can be exploited. However, in the zoned state, even with the separation of the lower part, more than 70% of the microgrid load is provided. It should be noted that because the steady-state conditions of the system are considered in the design, the dynamics and transient state of the system are not considered. Therefore, the operator can prevent the shutdown of the microgrids created by using two corrective actions to remove the load and increase the non-probabilistic production. For this purpose, three errors were applied in each of the three microgrids obtained from Scenario 2. Assuming that the first error is in the first microgrid and the range of 2 to 11 buses, if the network is not operating as a microgrid, all the buses after the error will be located without electricity. However, in the microgrid mode, the second and third microgrids will be located. They can be retrieved after an error occurs and disconnected from the upstream area and provide other network loads as an island by eliminating lower priority loads. Suppose the error occurs in the second microgrid, e.g., in the range of 13 to 23, after recovery. In that case, only the microgrid between the error and the start of the third microgrid will be without electricity. The necessary loads of the third microgrid will be provided with a suitable reloading plan. In the end, with an error in the third microgrid in the range of 25 to 34 buses from the fault location to the end of the network, all these loads will be disconnected, and in this case, there is no difference in the middle of any of the operating modes. In Table 10, for example, an error is applied in each microgrids, and the reliability index is evaluated in the two cases mentioned.  
At the same time, the investment cost of installing circuit breakers and creating separate operating centers for each microgrid to create the ability to become an island is cost-effective in terms of improving network reliability due to the return on the investment use of renewable products. Therefore, the importance of considering the issue of planning combined with the zoning of current conventional networks and the transition to new self-sufficient microgrids is evident.