Modular VSC converter based HVDC power transmission from offshore wind power plant: Compared to the conventional HVAC system

The size of wind power plants (WPPs), both physical and in terms of power rating, is rapidly growing. More and more WPPs are commissioned as offshore as well as the distances from the WPP to the coast are increasing. The problems associated with long HVAC sea-cables are well documented. Alternative power transmission options with HVDC systems are under consideration. In this paper, a comparison between a conventional HVAC transmission system and a HVDC system equipped with modular voltage source converters is provided. The comparison is based on the total energy transmission capability and the energy losses. A complete procedure of evaluating the energy transmission as well as losses in both systems are presented. A brief discussion about the limitations of HVAC transmission is also included in the paper together with advantages and disadvantages of both systems.