MVDC PLUS® – the grid connector

Economic, flexible, powerful MV transmission
Regional HV & MV sub-transmission networks and MV distribution grids play a vital role in controlling the omnidirectional power flows that characterize today’s and even more so tomorrow’s energy ecosystems. MVDC PLUS® helps to manage this challenge and offers additional advantages.
Ready for the future energy distribution system
MVDC PLUS® is Siemens Energy’ answer to the challenges that regional high-voltage transmission networks and medium-voltage distribution grids increasingly have to deal with. It makes the advantages of DC technology available for applications in AC networks.Reinforce MV transmission all the way
Transmission distances grow in increasingly liberalized markets. Growing infeed from distributed power generation units causes power quality and grid stability issues. Grid infrastructure needs to be expanded, upgraded, and reconnected to handle the volatile demand for flexible electricity supply. Distribution System Operators (DSOs) require a higher degree of transmission autonomy to fulfil today’s expanded range of tasks.
Siemens Energy’ MVDC PLUS® is the efficient, robust, reliable, and compact solution that provides answers to all these challenges. It increases transmission capabilities, strengthens the grid infrastructure, helps minimize losses, and provides reactive power compensation and load flow control.
MVDC PLUS® improves connected grids through active load flow control and provision of reactive power. Grids with different frequencies, voltage levels, and power quality can be decoupled with a DC link. Intermittent power infeed from renewables is facilitated and grids are stabilized.
MV OHLs can be kept below the treetops at heights <15 m, require smaller corridors, and are easy to implement. This helps to keep visual impact to a minimum, improve the public acceptance of transmission systems, and speed up planning approval and construction.
The conversion of existing AC systems to DC systems using MVDC PLUS® boosts their transmission capabilities by 20 to 80 percent. This helps avoid network expansions and avoid time consuming approval procedures. At the same time, grid stability is improved by the STATCOM functionality MVDC PLUS® converters provide.
The implementation of MVDC links and additional grid nodes for up to 150 MW makes DSOs much more independent from HV transmission systems, provides for increased flexibility in line planning and expands the scope of options for the grid connection of distributed generation.
Compact and cost-efficient MVDC PLUS® connections via cable or compact overhead lines enable cost-efficient power transmission over distances – perfect for the grid connection of islands, offshore platforms, and remote locations. Black start capabilities ensure the remote restart of independent areas.
One solution, many advantages
MVDC PLUS® comes in three standardized type ratings and is based on Siemens Energy’ proven multilevel voltage-sourced converter technology. This ensures universal applicability and renders numerous benefits.A smart combination of advantages
MVDC PLUS® combines the best of AC and DC transmission:
- The simple design, robustness, reliability and low costs of common AC technology that can be easily integrated in existing transmission networks
- The long-distance transmission capabilities, high transmission capacity, active power flow control, reactive power compensation, and STATCOM properties of HVDC PLUS® technology
Proven high-quality technology
MVDC PLUS® is based on Siemens Energy’ renowned and proven HVDC PLUS® technology. The symmetrical monopole layout basically represents the HVDC-topology slimmed down to its basic functionality. At the heart of the system are rugged and powerful multilevel voltage-sourced converters (VSCs). They produce an almost ideal sinusoidal waveform and this way ensure consistent power quality. The converter stations allow for bidirectional power flow and can operate as STATCOMs.