Wind power is one of the fastest growing renewable energy sources. Wind turbines are now becoming part of our landscape, and if before some people found them ugly, now they rarely notice them.
One key limitation of wind turbines, however, is that their ability to generate power depends purely on the speed and strength of wind, often causing oscillations in the flow of power through the grid. This often results in reduction of the efficiency of power transfer, and in some cases even leads to power outages. A team of U.S. scientists decided to look into the problem and not only identify the reasons behind it, but also find a solution to it.
The researchers from North Carolina State University and John Hopkins University found that the number and nature of oscillations, or disturbances in the power transfer, highly depends on the the location of the wind farms in the grid. Of course, if the oscillations are reasonably small they can be controlled from the inside of the power generators, however often they simply result in lower efficiency and affect the stability of the grid.
The study published in the journal IEEE Transactions on Power Systems, presents a new technique that deals with these disturbances by synchronizing the wind power controllers inside the turbines and a controlled battery management system. The new controllers that the team designed are linear and co-dependent for the wind power and the battery system charging mode. This coordination allows distribution of excess energy when the wind is stronger to the energy storage systems instead of sending it all to the grid, and therefore ensures that back-up energy is available in case of need of restoration of the stability of the grid.
It is not very often that we see a study identifying a problem, and presenting a solution to it. If it is a practical one or not, however, it is up to specialists and investors to say. We can only hope that the findings are taken on board so that the energy that goes to the grid can be that much greener.
Image (c) Reuters
