6. Conclusion

Since commercial devices are designed for single-phase or three-phase supply, the DC network can only be auxiliary, but reliable, since it can be backed up by batteries or supercapacitors, which are nevertheless very expensive.

Its development will depend to a large extent on lower prices for converters, photovoltaic panels and new energies, most of which generate direct current. The use of batteries and storage elements, although still useful, will then be reduced. However, this use could increase if the price per installed kilowatt-hour fell considerably.

The "third conductor" could be used not only for cable condition monitoring, but also for richer data transmission, especially of the Internet. This would make the cable installation more cost-effective.

In fact, direct-current networks linking mainly renewable...