Permanent magnets provide greater efficiency in wind energy
Permanent magnet generators improve the
financial performance of wind power projects and are the answer for turbine
manufacturers, who are looking for a powertrain that offers high efficiencies
with partial load, greater availability and a simplified grid connection that
protects the generator from any type of disturbance.
These permanent magnet generators, too, can be applicable to direct drive, medium speed and high speed systems.
A common view is that permanent magnet
generators are applicable only to direct drive offshore wind turbines, where
their use eliminates the potentially problematic gearbox. However, permanent
magnet generators offer so many compelling advantages that they are now being
designed as gearbox transmissions to operate at a wide range of output speeds.
Permanent
magnet generators replace double feed induction
Dual-powered induction generators have
provided the wind power industry with many years of excellent service. However,
the number of undeveloped Class I wind sites decreases with each passing year,
while project developers demand improvements in plant reliability and
availability.
In this regard, permanent magnet generators
offer a wide range of performance advantages to wind farm developers and
operators that can make a significant and positive difference to project
economics.
For example, permanent magnet generators are
incredibly flexible. Your design can be customized for:
The
permanent magnet generator designer can exchange the properties and weights of
magnet, stator copper and stator lamination to achieve the required objectives
without the need for the turbine OEM to accept a standard, market-optimal,
non-optimal generator.
Permanent
magnet and rare earth generators
The magnets in the rotor of a permanent magnet generator use rare earth metals. The magnets used in these generators generally contain ~ 30% Nd (neodymium) in weight, and most of the remaining weight is made up of low-cost ferrous materials.
Permanent magnet generators are flexible.
They allow wind turbine designers to consider powertrains with a wide range of
topologies, from conventional modular gearboxes and generator arrays to fully
integrated systems (or hybrids) assembled within a single cabinet, and even
direct drive systems that operate without a gearbox. Every topology has merits.
In addition, a conventional high-speed drive
train with fully independent or modular gearbox and a permanent magnet
generator appears in the layout of the modular drive train.
This gives the turbine OEM the maximum
flexibility to select the suppliers of the gearbox and generator, as both are
completely independent.
Finally, by integrating some components of
the powertrain, the overall length and weight can be significantly reduced.
This is achieved by combining the main bearing and gearbox for a medium or high
speed shaft design, or by close coupling of the gearbox and generator as shown
in the integrated powertrain layout.
All these features of permanent magnet generators make it possible to reduce costs in wind energy. If you want to know more about this technology, at IMA we can advise you on the magnetism solution that best suits your project. If you have questions, you can contact us.
