DauerGleichstrom

DauerGleichstrom, in German typically abbreviated as DGC, refers to direct current that flows in a single, constant direction with negligible ripple. In practice, DC circuits aim for steady operating points, though real-world sources such as converters, batteries or solar cells can introduce small variations. The concept contrasts with Wechselstrom (alternating current), where the current reverses direction periodically.

Direct current is produced by various means. It can originate from DC generators with commutators, but in modern networks most DC is generated by rectifying alternating current through power electronic converters or by DC sources such as batteries, fuel cells, photovoltaic systems and certain energy storage devices. DC is widely used where stable voltage and fast response are advantageous or where AC synchronization is impractical.

Applications of DauerGleichstrom include HVDC transmission, DC distribution networks, traction systems for railways and trams, and DC microgrids. HVDC links are used to transfer large amounts of power over long distances or undersea using converter stations at each end, offering lower losses, controllability of active and reactive power, and the ability to interconnect asynchronous AC grids. In urban and industrial settings, DC is common inside equipment and facilities, where DC buses feed electronics, data centers, and renewable energy systems.

Advantages and challenges: DC transmission can reduce line losses over long distances, avoids reactive power management, and enables straightforward interconnection of asynchronous networks. However, it requires high-capacity converters, sophisticated protection against DC faults, insulation strategies for steady unipolar currents, and ongoing maintenance of power-electronics equipment, which can entail higher initial costs.

Historically, DC technology competed with AC in the late 19th century and later gained renewed importance with HVDC for long-distance and submarine links.