Integration of wind power by DC-power systems

Abstract

The world climate changing is driving the electric power production towards renewable energy sources. The development of wind turbines has reached the power level of 5 MW and wind farms up to 1000 MW are planned. Investigations have shown that the cost for production of wind energy is in the same level as coal and gas. The large amount of hydro power in the Nordic countries can be used to compensate for the irregularity of producing wind power in Europe. High voltage direct current connections between Sweden and Germany, with a wind farm between can be a solution in the future.

Offshore wind farm with centralised power conversion and DC interconnection

“…Such topology is likely to be uneconomical in practice since the converter currents would be well below their ratings. The use of DC/DC transformers on individual machines may offer a suitable solution, but there are many challenges in developing a suitable DC/DC boost converter [8]. Because of limitations in the rating of present wind generators, it is proposed to connect each converter to a group of wind generators, which leads to the concept of centralised power conversion [9].…”