Direct and alternating currentDirect current
Direct current is characterised by its temporal constancy with respect to the strength and direction of the energy flow. It has taken on increasing importance in energy technology in recent years. This is due to long-distance cable connections. With large distances, such as when connecting offshore wind farms, alternating current reaches its economic and technical limits as a result of the reactive power requirement. Here high-voltage direct current transmission (HVDC) is being increasingly used.