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Induction heating of windmills

What role has induction technology played in the promotion of green wind power?

Oil crisis… energy crunch… global warming. All of us are aware of the need to find sustainable alternatives to fossil fuels. One of the most promising alternatives is wind.

It’s clean, it’s free, and supplies are unlimited. There’s just one problem. How can we harvest it? EFD Induction explains how modern technology extracts energy from the skies—and what EFD Induction is doing to help it.

There’s nothing new about wind energy. For millennia mankind has harnessed it to move ships. And, of course, windmills have been grinding grains, pumping water and irrigating fields for centuries. What is new is the prospect of using wind to supply entire cities with electricity—something that’s not as far-fetched as it sounds.
For example, according to new figures from the Global Wind Energy Council (an international wind power advocacy organization),  60.4 GW of wind energy capacity was installed globally in 2019, a 19 per cent increase from installations in 2018 and the second-best year for wind historically.Total capacity for wind energy globally is now over 651 GW, an increase of 10 per cent compared to 2018.
The figures are impressive. But what role has induction technology played in the promotion of green wind power? To answer that, we first have to examine the structure of a typical modern wind turbine. Basically, a wind turbine consists of tower-mounted rotors which, when turned by the wind, rotate a low-speed shaft that is connected via a gearbox to a high-speed shaft that supports the generator.
To start with, a large bearing is needed in order for the rotors to turn. But not just any bearing will do. Due to heavy loads and punishing torque, the rotor bearing must be custom hardened—something for which our multi-axis hardening solutions are ideal. EFD Induction vertical hardening systems are also perfect for treating the shaft connecting the rotors to the gearbox

In gear with multi-frequency

The heart of any wind turbine is the gearbox. Here the leisurely turns of the rotor blades are transformed into the approximately 1500 revolutions per minute required by the generator. Traditional hardening technologies cannot deliver uniform hardness patterns to the complex geometries of the gears. But EFD Induction’s multi frequency hardening solutions can. Our patented multi frequency technology delivers high and medium frequency power simultaneously to a single induction coil. The proportion, or ‘mix’ of frequencies can be adjusted at will to match the specific requirements of each workpiece. The result is perfect----- -and reproducible------contour hardening. EFD Induction hardening systems can also be used for the tooth-bytooth hardening of the yaw motor. Crucial to the turbine, the yaw motor keeps the rotors turned into the wind. The yaw motor swivels the rotors into the correct position by means of a cam wheel that engages a large yaw bearing mounted on the turbine tower. An electronic controller that is constantly fed data by an anemometer mounted on the nacelle tells the yaw motor when to turn the rotors.

Beyond hardening

EFD Induction’s contribution to wind turbines is not limited to component hardening. The generator, for instance, requires brazing, an operation easily performed by our range of mobile Minac induction power systems. Featuring long flexible connector cables and push-trigger hand-held transformers, Minac systems let operators braze even the most difficult-to reach generator parts. Moreover, Minac comes in ‘twin’ versions. These models feature two independent power outputs that can function simultaneously under identical or different operating parameters. And Minac’s mobility makes it ideal for on-site repairs and maintenance at wind farms. Much has been made of the ‘green’ or ‘environmentally friendly’ nature of wind turbines. But induction technology has the potential to make this energy source even greener. That’s because induction is itself an inherently clean process. It eliminates naked flames (and the resulting smoke and fumes), reduces the need for fuel transports, and promotes safer, healthier work places. Induction is also energy-efficient. There is none of the massive heat loss associated with ovens and furnaces. In fact, induction and wind power form a ‘virtuous circle’----- -clean electricity from the wind powers induction heating systems that make turbines that generate clean electricity … It’s a beautiful partnership, one that EFD Induction is proud to be a part of.