5.1.- SMART GRIDS AND POWER SYSTEMS

Due to the inclusion of renewable energies in electric power systems, the decentralized nature of electricity generation is increasingly evident. That is why the distribution of power flows has become a great challenge because, according to Kirchhoff’s laws, the electric current tends to circulate, to a greater extent, by power lines with lower impedance. This causes a great imbalance in the electrical grids and the subsequent efficiency reduction. The great progress made in power electronics have allowed to challenge Kirchhoff’s laws successfully, managing to control power flows in the most complex power grids.

Among the cutting-edge technological developments integrated in the smart grids nowadays to control power flows, there are: phase-shifting transformers (PST), flexible AC transmission systems (FACTS), static synchronous compensators (STATCOM), thyristor controlled series capacitors (TCSC) and static frequency converters (SFC). These technologies are installed in certain electrical substations to control the power flows of the grid, as well as the power factor. Thus, it substantially improves the efficiency of the entire electrical system.

Thanks to this technological evolution, which has given rise to smart grids, it has been possible to integrate renewable energy sources, such as wind power and photovoltaic power, into the grid, as well as to include electric vehicles in today's society. In turn, this has significantly reduced greenhouse gases (CO2).