Application of Permanent Magnets in Wind Turbines

Ever wondered how wind turbines work? Most likely, you have, but you certainly would have questions on your mind. For instance, you may be curious to know how exactly those towering structures with two blades are able to generate enormous amounts of electricity to power many households across the country.

At the core of the mechanics in wind turbines are permanent magnets, a special type of magnet with strong permanent magnetic properties. Until the invention of wind turbines, the primary source of power was fossil fuels like coal and petroleum. While these were tremendously helpful, they had a major flaw; they emitted alarming amounts of carbon dioxide, which is toxic to both humans and the environment.

Why wind turbines are preferable?

The general acceptance of wind turbines as a major power source lies solely because they are a form of clean energy. Keep in mind that environmental sustainability has been a buzz topic for quite some time now. The fact that wind turbines generate only clean energy (without emission of any environmentally toxic material) makes them a staple in the power industry. They are here to stay - and central to that purpose is the presence of permanent magnets like neodymium magnets.

Neodymium magnets are a type of rare-earth magnet. Another example is the neodymium-iron-boron combination. These turbines are used in wind-turbine designs to reduce costs, improve reliability, and drastically reduce the need for continuous and costly maintenance.

So, how do permanent magnets work in wind turbines?

The operation of wind turbine generators is based on the principle of electromagnetism and it typically follows the design of the first electromagnetic designed by Michael Faraday in 1831. When an electric conductor is rotated within a magnetic field, it will generate electricity. As the blades of the turbines rotate in the direction of the wind, electromagnetic induction occurs within the magnetic field of the permanent magnet in the turbines to produce electricity. A generator connected to the shaft of the wind turbine converts the motion of the blades to electricity.

But instead of using slip rings, as employed in electromagnets, the permanent magnets in wind turbines use the magnetic field of strong rare-earth magnets.

Difference between electromagnets and permanent magnets

Unlike electromagnets, permanent magnets do not require power from any external source. The main difference between using electromagnets and permanent magnets in wind turbines is that electromagnets require slip rings to power the electromagnets, whereas permanent magnets do not. Again, the gearboxes require continuous maintenance, which can significantly raise costs.

The function of the gearbox is to convert the low rotational speed of a turbine shaft to the higher speeds needed in the induction generators to produce electricity. But gearboxes cause friction and can reduce performance. With the neodymium magnet, for instance, replacing the electromagnets, we can achieve higher efficiency in the turbines, decreased efficiency, and lower cost of maintenance.

Today, engineers have developed even more sophisticated electromagnetic generators which work in tandem with the wind power trapped by the wind turbines to rate electricity for local consumption in households, schools, hospitals, business establishments, and so on. As of now, one wind turbine can produce up to 113 GW and can power about 250 t0 300 houses, judging by the intensity of the wind.

How magnets make for better mounting solutions in wind turbines

Beyond helping to generate electricity, permanent magnets play a crucial role in helping to maintain the integrity of the tall walls of the turbine. If you`re privileged to look inside a wind turbine generator, you`ll see lots of cables and very long ladders attached to the walls. Some of them contain elevators to allow workers to access the turbine nacelle.

The traditional solution for achieving this is to drill holes into the walls of the turbine to mount the brackets or weld the brackets onto the walls for holding the brackets. Unfortunately, this solution can impact the integrity of the walls, reduce their strength, and make them prone to corrosion.

Thankfully, permanent magnets are stepping up the game by allowing engineers to mount brackets on the wall without drilling any holes or welding anything. Some turbine manufacturers ingeniously use a magnetic mounting system to attach wall brackets and other essential materials onto the wall of the turbines. Strong rare earth metals like neodymium magnets are an excellent choice for this kind of application.

Conclusion

Considering that permanent magnets play an important role in helping the world to generate clean electrical energy, it is safe to say that permanent magnets are indispensable. Interestingly, they are applied in many other fields, such as medicines, electronics, etc.