HVDCSysteme

HVDCSysteme refers to technologies for transmitting electric power using direct current at high voltage. They enable the efficient transfer of large amounts of electricity over long distances, interconnection of asynchronous alternating-current grids, and integration of offshore or submarine generation sources with onshore networks. Compared with high-voltage alternating current transmission, HVDCOften reduces losses over long distances, avoids reactive-power issues, and provides precise control of power flows.

An HVDC system comprises a converter station at each end of a direct-current link, a direct-current conductor (overhead line or submarine cable), and a protection and control subsystem. Converters use either line-commutated technology based on thyristors (LCC) or voltage-source technology based on solid-state devices (VSC). The stations include transformers, converter bridges, dc reactors or filters, and auxiliary equipment, along with protection, control software, and grounding schemes.

Two common architectures are point-to-point HVDC and multi-terminal HVDC (MTDC). LCC links require a strong AC network to provide reactive power and commutation support; VSC links can operate with weaker AC systems, offer black-start capability, and can form grid-following or grid-forming modes. HVDC is widely used for submarine cables, cross-border interconnections, and offshore wind connections to land grids, as well as for long hinterland links.

Benefits include lower losses for long-distance transmission, reduced right-of-way, better control of power flows, and the ability to connect asynchronous grids. Challenges involve high capital costs for converter stations, converter losses, the need for specialized protection such as DC circuit breakers, and ongoing complexity in control and protection.

Ongoing developments focus on expanding MTDC networks, modular architectures, and VSC technology to enhance reliability, scalability, and integration of renewable energy.