## 4 Discussion  
Cascading systemic accidents lead to the disruption of power supply for a significant number of consumers across vast areas. The restoration of the normal operation of an EPS after such accidents takes from several hours to several days, since such accidents can cause damage to specific components within the EPS, necessitating a thorough emergency restoration effort. The developed algorithm allows the timely identification of the possibility of cascading failure processes and their development pathways in EPSs with network topologies of varying complexity. This capability of the algorithm was demonstrated by the findings from calculations conducted for three test scenarios and one real-world EPS scheme. Figure 13: A 3D graphic surface of the non-uniform distribution of the current (_l_, p.u.) after Step 7 of the cascading failure process. The algorithm can be employed both to plan and manage power flows in EPSs and to strategize about EPS expansion, facilitating the selection of the best technically and economically justified topologies and operational measures. This helps reduce the non-homogeneity of EPS parameters and, accordingly, the possibility of cascading systemic failures. Simulating possible trajectories for cascading failure development in electric power systems enables dispatching personnel to provide a set of topology and operational strategies in the stage of operation planning to prevent the transition of emergency disturbances into a systemic failure. The cost indicators of FACTS devices, as well as the cost of electricity, given in this paper, can vary considerably across different countries, exhibiting upward and downward fluctuations. This depends on the availability of in-house developments of FACTS devices and their manufacturers, the performance indicators of generating equipment at operating power plants, and the cost of primary energy resources. Consequently, the decision on the implementation of certain topology and operational measures should be made on the basis of a full-fledged feasibility study relying on comprehensive technical and economic analysis. The simplified technical and economic calculations provided in this paper did not factor in the costs of design and survey work, the examination of design documentation, and author's supervision, which can reach 6-8% of the total cost of the equipment. Nor did the calculations consider the cost of land plots for the installation of FACTS devices in substations and overhead PTL supports. The areas of land plots for overhead PTL supports depend on the type and material of supports, span lengths, soil characteristics, and others. In densely populated areas, there are no opportunities for building new overhead PTLs. In large cities and megalopolises, building new overhead PTLs is generally prohibited by urban planning regulations. The cost of constructing a 500 kV power line in cable design is several times higher; therefore, the use of other measures is more preferable. The calculation results proved that connecting DG facilities to individual nodes of the EPS network could enhance the survivability of the EPS and boost the reliability of power supply to consumers. However, it is essential for DG facilities to maintain a surplus of power that can be supplied to a network under certain topology and operational conditions, as directed by the EPS dispatching personnel. This capability must be incorporated during the design phase of DG facilities. Based on the steady-state calculations, it is necessary to identify the most advantageous nodes for connecting DG facilities. This is important for developing strategies to encourage the distributed generation owners to build and connect their facilities to these EPS nodes. While it is clear that consumers benefit from loading power plants that produce \"cheap\" electricity, there are specific topologies and operational conditions under which it makes sense to load power plants generating \"expensive\" electricity, as well as DG facilities.