Spaniards Make Offshore Wind Power Play

Scientists from Universidad Carlos III de Madrid (UC3M) have designed a new control system for offshore wind farms which is said to allow power transmission to the coast in a simpler, more flexible and cheaper way than current solutions.

This innovation, which the UC3M researchers have protected by a set of patents, allows the use of a diode rectifier station in the offshore platform of a high voltage direct current (HVDC) link. In this way, the wind turbines’ alternating current (AC) can be easily converted into direct current (DC) for the HVDC transmission, UC3M said.

For this, the scientists have developed a distributed control system which allows to synchronise and regulate the electrical voltage and frequency of the offshore wind turbines. This is said to allow the transmission of energy to the general network through an HVDC link with a diode rectifier station.

“It is less complicated, cheaper and more flexible than other current solutions,” said one of the authors of the patents, Santiago Arnaltes Gómez, head of the UC3M Power Control Group.

This new system synchronises the wind turbines without using any additional element since it uses the wind turbines’ capacity to contribute to voltage and frequency control. One of the key factors is the use of diode rectifier stations, which allow to reduce the cost of the offshore rectifier platform by up to 30 percent, according to some studies.

“What we have managed to do is to provide the technical feasibility necessary in order to use this kind of rectifiers, since at the moment wind turbines still cannot work with them,” said another of the authors of the patent, José Luis Rodríguez Amenedo, from UC3M’s Department of Electrical Engineering.

The researchers have developed three patents in relation to this system, which they have validated by means of simulations, small-scale laboratory prototypes and proofs of concept. The next step is its commercialisation and industrialisation.

“Our main clients would be large electricity companies that have the capacity to make these diode rectifier stations,” the researchers said.