HVDC Light® is the successful and environmentally-friendly way to design a power transmission system for a submarine cable, an underground cable or network interconnection.
HVDC Light
® is HVDC technology based on voltage source converters (VSCs). With extruded DC cables, power ratings from a few tens of megawatts up to several hundreds of megawatts are available.
HVDC Light® cables have extruded polymer insulation. Their strength and flexibility make the HVDC Light® cables well suited for severe installation conditions both underground as a land cable and as a submarine cable.
The converter station design is based on voltage source converters (VSCs) employing state of the art turn-on/turn-off IGBT power semiconductors that operate with high frequency pulse width modulation.
HVDC Light® has the capability to rapidly control both active and reactive power independently of each other, to keep the voltage and frequency stable. This gives total flexibility regarding the location of the converters in the AC system since the requirements of short-circuit capacity of connected AC network is low (SCR down to zero).
Installation of an HVDC Light station | ... | The HVDC Light® converter station design is based on a modular concept. For DC voltages up to ±150 kV most of the equipment is installed in enclosures at the factory. |
For the highest DC voltages the equipment is installed in buildings. The required sizes of the site areas for the converter stations are also small. All equipment except the power transformers is indoors. Well-proven and tested equipment at the factory make installation and commissioning quick and efficient.
The stations are designed to be unmanned. They can be operated remotely or could even be automatic, based on the needs of the interconnected AC networks. Maintenance requirements are determined mainly by conventional equipment such as the AC breakers, cooling system, etc.
A pair of HVDC Light® cables | ... | The cable system is complete with cables, accessories and installation services. The cables are operated in bipolar mode, one cable with positive polarity and one cable with negative polarity. The cables have polymeric insulating material, which is very strong and robust.
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This strength and flexibility make the HVDC Light
® cables perfect for severe installation conditions:
- The submarine cables can be laid in deeper waters and on rough bottoms.
- The land cables can be installed less costly with ploughing technique.
- HVDC cables can now also go overhead with aerial cables.
The environmental benefits is:
- Magnetic fields are eliminated since HVDC Light® cables are laid in pairs with DC currents in opposite directions.
- Risk of oil spill, as in paper-oil-insulated cables, is eliminated.
- The cable insulation is PE based and not dangerous.
- The cable metals can be reused.
Power transmission via cables gives
- no visual impact
- no ground current
- no electromagnetical fields.
HVDC Light
® is an alternative to conventional AC transmission or local generation in many situations. Possible applications include:
- Connecting wind farms
- Underground power links
- Powering islands
- Oil & gas offshore platforms; power from shore
- Asynchronous grid connection
- City centre in-feed