The typical alternating current voltages in the transmission lines are from 69 kV to 750 kV. Voltages from 69 kV to 500 kV are normally transmitted in alternating current and for values greater than 500 kV, it will be necessary to carry out a study to know if it is economically feasible to transmit in alternating or continuous voltage. For example, in the Itaipu hydroelectric plant, the 750 kV line and the alternating voltage line is that of 600 kV, continuous.
When the transmission is made in direct current, a rectifying substation transforms the alternating voltage into continuous. This voltage is established at all points of the transmission line until reaching the consumption centers, where an inverter station converts it to alternating voltage, before distributing it to consumers.
An important aspect of DC transmission is the reduction of losses in the transmission line. The electric power distribution stage starts at the voltage lowering substation. First, the transmission line voltage is reduced to the default values of the primary distribution networks. boston cluthes brakes
The voltages are distributed to three-phase transformers, which can serve single-phase, two-phase or three-phase consumers. The voltage in the primary distribution network is 13.8 kV and, when passing through the transformer, reduces to 127 V and 220 V.