Advanced Technologies, Expert Implementation

RXPE Circuit

We have set a new precedent with innovative Smart VSC-HVDC solutions. Projects include the world’s first multi-terminal Smart VSC-HVDC facility, developed for China’s Nan’ao Island Wind Power Plant.

In this section

SMART VSC HVDC Transmission

Smart Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) is unlocking new possibilities for the grid of the future.

HVDC systems’ highly efficient transmission of bulk power across very long distances brings significant economic and technical advantages. However, deployment has traditionally been limited by problems surrounding power flow and protection when connecting to AC systems.

Introducing VSC power conversion addresses this challenge. VSCs can generate or absorb reactive power and allow real and reactive power to be controlled independently. What’s more, the direction of power flow may be reversed without changing the polarity of the DC voltage. VSCs do not depend on the presence of a synchronous AC voltage for their operation and may be used to feed weak or passive networks.

Technical details

Converters form the terminals of an HVDC transmission system and are used to adapt AC power to DC (rectifier) and DC power to AC (inverter). Conventional HVDC links are based on current source converters (CSCs) with thyristors; VSCs were first used in the late 1990s. 

Advantages of VSCs over CSCs are rooted in their use of self-commutated semiconductor devices such as insulated gate bipolar transistors (IGBTs). These can be turned on and off with a gate signal, bringing multiple advantages for power system applications. Benefits include independent control of active and reactive power at both converter stations as well as easy linkage of multiple terminals. Further advantages include the ability to supply power to weak grids and black-start capability.

VSC-HVDC demonstrator

RXPE has spearheaded Smart VSC-HVDC innovation and has numerous successful installations. We have a 36MW VSC-HVDC Demonstrator for long-term testing of our technologies; contact us if you’d like to visit this facility and witness VSC in operation.

Reference Projects



DC Voltage (kV

Rating (MW)

Application Type

Contract Award Date

Commissioned Date


China Southern Grid




April 2013

Dec 2013


China Southern Grid




Nov 2014

Aug 2016


State Grid of China Corporation




April 2016

May 2019


China Southern Grid




Aug 2018



China Three Gorges/ China General Nuclear Power Corporation JV



Point to Point

Nov 2019


Technical parameters

Rated capacity 10MVAr to +5000MVAr
DC voltage +/-800kV
Transmission length 40km to +100km
  • Offshore wind farms
  • International grid interconnection
  • Long-distance transmission
  • Remote renewable projects

Contact us for more detail about our Smart VSC-HVDC Transmission solutions

+44 (0) 161 2330689

email us

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