One of the applications of the transformers and the change of voltage and current in electric power plants, ensuring that they meet the largest possible number of end users who use the voltage in different values: industrial, commercial and residential.
Hydroelectric plants use water from reservoirs of large lakes or rivers to move the turbines. Already the thermoelectric plants use fossil fuels or nuclear energy, whose steam turns the turbines. In general, hydroelectric and thermoelectric power plants are away from large consumers of electricity, and this goes to them through transmission lines, stations and substations. HOR04LBHP18
During the course, numerous transformers are used, which not only change the voltage value and control the current, but also maintain stable electrical power and reduce Joule losses.
Another convenience of transformers is that the cables used in the transmission line need not be too thick. Generally, the plant generates voltage in the order of 10 000 V, that the voltage transformer increases to 150 000 to 400 000 V. The acoustic voltage of 400 000 V is not increased to avoid the corona effect that causes loss of energy.