Some work of literature was also developed during this week, and was even made an introduction to the study of direct current transmission systems.

Schema definition of multi-terminal HVDC network through the equational representation of the lines and buses. Assuming that the lines are represented by the model in pi, as in figure 1, the following equations represent the network shown in Figure 2.

- Voltages equations at nodes (voltage in a similar capacity at the ends of lines with the capacity of the cable in parallel with the capacity of converters);
- Current equations of the lines;
- Equations of the flow of currents and powers in the nodes;

**Figure 1**

Highlighting that the network under test is a Bipolar Network, so this representation is only one pole, the other is connected in parallel with connection to the same ground point.

**Figure 2**