## 5 Simulation Results
### Case Analysis Results  
The switches S\({}_{1}\)-S\({}_{58}\) in the system are coded by 0-1, where 0 means switch off and 1 means switch on. In the initial operating state, except for the emergency power supply, other components are put into operation, and the tie lines are disconnected. The initial switch coding state is: 11100 11100 11111 11100 11110 01111 11001 11111 11001 11100 11111 100. The initial system topology is shown in Figure 8.  
(1) Fault scenario 1. The line between L\({}_{19}\) and B\({}_{4}\), and the line between L\({}_{20}\) and B\({}_{4}\) are faulty. As a result, S\({}_{36}\) and S\({}_{37}\) are disconnected. Based on fault scenario 1, S\({}_{36}\) and S\({}_{37}\) are enabled and do not participate in network reconstruction. System coding and network reconstruction are carried out for the remaining switches. When the MPGA is run five consecutive times, its convergence evolution process is shown in Figure 9.  
The optimal convergence result is the same for multiple times, and the optimal fitness is 0.98197. The average time of the network reconstruction process is 1.03 s. The corresponding optimal switch coding state is: 11100 11100 11111 11100 11110 01111 11001 00111 11001 11100 111100 11111 1000. Decoding the results, the optimal network reconstruction scheme is obtained as: switch S\({}_{36}\) and S\({}_{37}\) are off, and other network topologies remain unchanged. This is consistent with the above analysis conclusion in this paper. When the line between the load and the distribution board is faulty, the load power supply cannot be restored through network reconstruction. The revised system topology is shown in Figure 10.  
(2) Fault scenario 2. Generator G4 in the distribution network quits operation due to failure, and the line between LB4 and B4 is broken down. Thus, S35 and S38 are disconnected. After fault, recover the regional power supply first. Y3 is used to supply power to the loads carried by LB4, and Y4 is used to supply power to loads carried by LB5 and LB6. Moreover, Y3 can supply power to L19 and L20 through LB6. At this time, switches S43, S44, S49 and S50 are closed. To avoid forming a ring network, switch S40 is disconnected. Since the emergency power sources cannot be used for long-term power supply, it is necessary to recover the power supply through whole network reconstruction and transfer the system to the power supply mode by the main generator. Based on the analysis of the current operating status of the system, generator G4 exits operation due to failure and cannot participate in the network reconstruction. The line between LB4 and B4 is faulty, so the loads connected to LB4 cannot be powered by the main generator through network reconstruction and can only be powered by Y3. Other loads are directly or indirectly connected to B4 and can be switched to the main generator power supply mode through network reconstruction. Figure 8: The initial system topology. Figure 9: Convergence procedure of the MPGA under fault scenario 1. According to fault scenario 2, compared with the initial operating status, switches S\({}_{35}\) and S\({}_{38}\) are disconnected due to faults and do not participate in network reconstruction. LB\({}_{4}\) connects Y\({}_{3}\), and they form a local power grid. Thus, S\({}_{41}\)-S\({}_{46}\) do not participate in the whole network reconstruction, and S\({}_{40}\) is disconnected before the network reconstruction. Before whole network reconstruction, the switch coding state is: 11100 11100 1111110 11110 011110 01111 11000 11010 11010 11111 11111 1100. MPGA is run five consecutive times. The convergence evolution process is shown in Figure 11.  
The results of optimal convergence are the same after running multiple times, and it can stably converge to the optimal network reconstruction scheme; the optimal fitness is 0.93295. The corresponding optimal switch coding state is: 10100 11100 11111 11100 11110 01111 1100 11011 11100 11101 1111.