## 2 Materials and Methods
### Stage 1. Input Data Management
#### 2.1.1 Topology Database  
The fast recognition of the topology for each electric network from the supervisory and control area of the DNO or TSO represents a strong point for the real-time use of the proposed methodology. All information on the electric substations, the classical power plants, and the wind farms connected to the network through an identification number assigned to the analyzed area by the DM will upload from the Topology Database. A procedure [34] based on a structure containing two vectors, VA and VC, associated with each voltage level, which speeds up the recognition process, is implemented to perform this task. Vector VA records each area of the electric network. Vector VE contains the elements (electric line/power transformer) from each area. The connection between the two voltage levels is done through the elements assigned to the transformers from vector VE associated with the lower voltage level. In the following, the recognized procedure is exemplified using the electric network with two voltage levels (110, blue color, and 220 kV, red color) from Figure 5.  
The 110 kV level, having seven buses, is divided into four areas, and the 220 kV level, with three buses, including the slack bus (SB), into two areas. The structure of the two vectors associated with the 110 and 220 kV levels is presented in Table 2.  
Thus, the identification of each element, representing the link between each pair of buses, is automatically performed. Moreover, the technical characteristics associated with the transformers with OLTC represent indispensable input data for the methodology. All this information recorded in the database is uploaded in matrix structures used in the next stage by the control algorithm. Table 3 presents, as an example, such a matrix structure. Figure 4: The flowchart of the proposed coordinated control methodology. The fields have the following signification:  
* _Bus i, Bus j_--represent the two terminals (_i_--input and _j_--output) of an element (line or power transformer) associated with the main components (electric substations, the classical power plants, and the wind farms) identified through the numbers in the topology;
* _Element_--is associated with the power transformer (\(T\)) or the line (\(L\)) between _Bus i_ and _Bus j_;
* _Voltage_--indicated the voltage level, in (kV), for the operation of the _Element_ between _Bus i_ and _Bus j_;
* _Type_--is the identification number of the element in the _Lines Database_ or _Transformers Database_ containing the technical specific parameters: rated voltage, resistance, reactance, conductance, susceptance, and the number of tap positions (in the case of the transformers);
* _Length_--is the length, in (km), when the _Element_ between _Bus i_ and _Bus j_ represents a line. If the _Element_ is a power transformer, then _Length_ = 0; \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Voltage Level** & **Vector** & \multicolumn{6}{c}{**Elements**} \\ \hline \multirow{2}{*}{110 kV} & VA & Area 1 & \multicolumn{2}{c}{Area 2} & \multicolumn{2}{c}{Area 3} & \multicolumn{2}{c}{Area 4} \\ \cline{2-8}  & VE & T1 & L1 & L3 & L4 & T2 & L2 & L5 & L6 & T3 \\ \hline \multirow{2}{*}{220 kV} & VA & \multicolumn{2}{c}{Area 1} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{Area 2} \\ \cline{2-8}  & VE & \multicolumn{2}{c}{L1} & \multicolumn{2}{c}{} & \multicolumn{2}{c}{L2} \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The structure of the two vectors associated with the two levels. Figure 5: Exemplification of the recognition procedure in the case of an electric network with two voltage levels (110, blue color, and 220 kV, red color) with 10 buses (including slack bus).