Stable power supply thanks to wind turbines

October 08, 2001

Wind turbines can help keep the voltage in the electricity network at a constant level. The power electronics in the turbines can effectively correct peaks and dips in the mains voltage. This is the conclusion reached by NWO-funded researchers.

Modern wind turbines are a good means of coping with fluctuations in the mains voltage. Such fluctuations occur when the demand for energy increases suddenly (for example when a factory turns on heavy machinery) or the supply decreases (for example if a nearby power station suddenly goes off line).

The electrical engineers at Delft University of Technology base their conclusion on a model which they developed to study fluctuations in the electricity network on a time scale running from seconds to minutes. At the moment, the task of maintaining the stability of the mains voltage is left entirely to power stations. In future, sustainable energy will become more important. Wind turbines and other sustainable energy sources will then need to help stabilise the mains voltage.

A large number of modern wind turbines are equipped with a power electronics converter that ensures that they produce the same voltage at all times, regardless of the rotor speed. Minor alterations to the power electronics and the controller can also ensure that the mains voltage is adjusted. The electronic system makes clever use of the properties of alternating current. In alternating current, the voltage crosses zero a hundred times a second. By sending electricity into the network at that moment, the power electronics can boost the voltage. Strangely enough, this does not need to cost much energy. 'Reactive power compensation', to give it its proper technical name, even works when there is no wind and the rotor blades are not rotating. In that case, the power electronics can extract the necessary energy from the network, precisely between two zero-axis crossings.

Not all types of wind turbine can help stabilise the mains voltage. One type is not equipped with the power electronics converter which is necessary. The principle behind this type of turbine is that the rotational speed of the rotor is constant and independent of the wind speed.

The NWO research team intend extending their model of fluctuations in the electricity network so as to have it model the influence of other sustainable energy sources, such as solar cells. The energy sector will be able to use the model to calculate what the maximum contribution of various sustainable energy sources can be without endangering the stability of the power supply. The model can also indicate what additional technology is necessary to ensure stability.
-end-


Netherlands Organization for Scientific Research

Related Wind Turbines Articles from Brightsurf:

Supersized wind turbines generate clean energy--and surprising physics
As wind energy scales up, researchers study the fluid dynamics challenges.

Safe flight: New method detects onset of destructive oscillations in aircraft turbines
''Flutter'' is a complex oscillatory phenomenon that can destroy aircraft turbine blades and has historically been the cause of several plane accidents.

New system uses wind turbines to defend the national grid from power cuts
A 'smart' system that controls the storage and release of energy from wind turbines will reduce the risk of power cuts and support the increase of wind energy use world-wide, say researchers at the University of Birmingham.

Wind beneath their wings: Albatrosses fine-tuned to wind conditions
A new study of albatrosses has found that wind plays a bigger role in their decision to take flight than previously thought, and due to their differences in body size, males and females differ in their response to wind.

Designing lightweight glass for efficient cars, wind turbines
A new machine-learning algorithm for exploring lightweight, very stiff glass compositions can help design next-gen materials for more efficient vehicles and wind turbines.

Quadrupling turbines, US can meet 2030 wind-energy goals
The United States could generate 20% of its electricity from wind within 10 years, without requiring any additional land, according to Cornell University research published in Nature Scientific Reports.

Supporting structures of wind turbines contribute to wind farm blockage effect
Much about the aerodynamic effects of larger wind farms remains poorly understood.

Wind and water
Damaging rains from hurricanes can be more intense after winds begin to subside, say UC Santa Barbara scientists.

Silverswords may be gone with the wind
In a new study in the Ecological Society of America's journal Ecological Monographs, researchers seek to understand recent population declines of Haleakalā silverswords and identify conservation strategies for the future.

Computer models show clear advantages in new types of wind turbines
Researchers from Aarhus University and Durham University have modelled the fluid dynamics of multi-rotor wind turbines via high-resolution numerical simulations.

Read More: Wind Turbines News and Wind Turbines Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.