Spanish researchers have developed a simple, flexible and cost-effective system to control the voltage and frequency in offshore wind farms.
The Universidad Carlos III de Madrid (UC3M) innovation features a diode rectifier station in the offshore platform of a high voltage direct current (HVDC) link.
According to the researchers, the new system – which is protected by a set of patents – ensures that the wind turbines’ alternating current (AC) can be easily converted into direct current (DC) for HVDC transmission.
“It is less complicated, cheaper and more flexible than other current solutions”, explains one of the authors of the patents, Santiago Arnaltes Gómez, head of the UC3M Power Control Group.
This system is said to synchronize the wind turbines without using any additional element, since it uses the wind turbines’ capacity to contribute to voltage and frequency control.
According to some studies, Diode rectifier stations have proven to reduce the cost of the offshore rectifier platform by up to 30 percent.
“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,” explains 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 commercialization and industrialization.
Integrating offshore wind farms into mainland electrical systems has been favorably viewed as a means of reducing fossil fuel consumption and greenhouse gas emissions.
The researchers contend that since a significant proportion of the large offshore wind farms planned are located far from the coast, a connection using HVDC links (in direct current) is technically and economically more suitable than a HVAC transmission system (in alternating current).
Image, video and content: Universidad Carlos III de Madrid (UC3M)