In recent years, mini-wind energy has been developing spectacularly. However, the level of efficiency of small wind
turbines is low. To address this problem, the UPV/EHU's research group
APERT (Applied Electronics Research Team) has developed an adaptative
algorithm. The improvements that are applied to the control of these
turbines will in fact contribute towards making them more efficient.
Small wind turbines tend to be located in areas where wind conditions
are more unfavourable. "The control systems of current wind turbines are
not adaptative; in other words, the algorithms cannot
adapt to new situations," explained Iñigo Kortabarria, one of the
researchers in the UPV/EHU'sAPERT research group. That is why "the aim
of the research was to develop a new algorithm capable of adapting to
new conditions or to the changes that may take place in the wind
turbine," added Kortabarria. That way, the researchers have managed to
increase the efficiency of wind turbines.
The speed of the wind
and that of the wind turbine must be directly related if the latter is
to be efficient. The same thing happens with a dancing partner. The more
synchronised the rhythms of the dancers are, the more comfortable and
efficient the dance is, and this can be noticed because the energy
expenditure for the two partners is at a minimum level. To put it
another way, the algorithm specifies how the wind turbine
adapts to changes. This is what the UPV/EHU researchers have focussed
on: the algorithm, the set of orders that the wind turbine will receive
to adapt to wind speed.
"The new algorithm adapts to the
environmental conditions and, what is more, it is more stable and does
not move aimlessly. The risk that algorithms run is that of not adapting
to the changes and, in the worst-case scenario, that of making the wind
turbine operate in very unfavourable conditions, thereby reducing its
efficiency.
• Efficiency is the aim:
Efficiency is one of
the main concerns in the mini wind turbine industry. One has to bear in
mind that small wind turbines tend to be located in areas where wind
conditions are more unfavourable. Large wind turbines are located in
mountainous areas or on the coast; however, small ones are installed in
places where the wind conditions are highly variable. What is more, the
mini wind turbine industry has few resources to devote to research and
very often is unaware of the aerodynamic features of these wind
turbines. All these aspects make it difficult to monitor the point of
maximum power (MPPT Maximum Power Tracking) optimally."There has to be a
direct relation between wind speed and wind turbine speed so that the
monitoring of the maximum point of power is appropriate. This needs to be done optimally. Otherwise, energy is not produced
efficiently," explained Iñigo Kortabarria.
Most of the current
algorithms have not been tested under the conditions of the wind that
blows in the places where small wind turbines are located. That is why
the UPV/EHU researchers have designed a test bench and have tested the
algorithms that are currently being used -- including the new algorithm
developed in this piece of research -- in the most representative
conditions that could exist in the life of a wind turbine with this
power. "Current algorithms cannot adapt to changes, and therefore wind
turbine efficiency is severely reduced, for example, when wind density
changes," asserted Kortabarria.
Source: Science Daily