DESIGN
The N43/600 is a development from Nordex where we partly have left the integrated concept
in favor of the semi integrated concept. The machine bed and the nacelle bottom is a one
piece unit in welded construction. The gearbox, main shaft, and main brake, are assembled
as a ridgid unit where no misallignments occur.
All structural parts, except the main frame, are casted in ductile cast iron, which gives
the freedom of optimal design and load distribution.The 3-stage brake system gives maximum
safety and component protection under all conditions. A strong and robust yaw system with
torque control , combined with "No just-to-the-limit" solutions, ensures a long
and error-free service of the machine. |
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ROTOR
The NORDEX N43/600 wind turbine has a three bladed rotor, mounted upwind
of the tower. The power limitation is done by stall-regulation. The N43/600 is supplied
with 3 blades, which has many advantages if compared to turbines with 1 or 2 blades: The
efficiency is higher, fatigue loading is smoother, and complex dynamic behaviour of a
teetered hub is avoided.
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BLADES
The blades are made from fibreglass reinforced polyester.
The blade tips are pivotable and can be turned 85 degrees respectively to the main blade,
thereby acting as aerodynamic brakes. The blade tips are activated hydraulically, and
hydraulic pressure is required to keep the tip in the operational position. During
rotation of the rotor, the sum of the centrifugal force on the tip and the spring force
will try to move the tip axially to the activation-position, and release of the hydraulic
pressure, either
intentionally by the control system or unintentionally by failure of the hydraulic system,
will cause the tips to deploy and the turbine to shut down. As such, the aerodynamic
brakes of the turbine are of a truly fail-safe design.
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HUB
The hub is made of ductile cast iron. The hub is fixed to the main shaft by bolts and
flanges.
MAIN SHAFT
The mainshaft is fitted in two strong spherical bearings which are grease lubricated.
Bearingfailure is prevented by constant temperature monitoring of the bearings. The main
shaft is forged in high grade Crom Molubden steel, heat treated ,and machined to exact
specifications. |
MAIN GEAR
The main gear is a custom built 3-stage design, with one stage high torque planetary step
and 2 stage helical step. The gear is splash lubricated, and can run on ordinary mineral
oil. To assure operation under even extreme high ambient temperature conditions, the
gearbox is fitted with an external oilcooler. The temperature in the gearbearings as well
as the oil is constantly monitored. The gearbox is fitted in two strong rubber bushings to
dampen the noise and torosional peaks, and at the same time allows the machinebed to flex,
so that when extreme loads occour no damage is done to the maingear and bearings.
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GENERATOR
The N43/600 can be delivered in two versions:
A single wound 4 pole asyncronous 600 kW machine, or
A double wound 4/6 pole asyncronous machine with generator capacity of 600/125 Kw.
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| The generator is fitted on rubber feet, to
minimize noise transmission, and is connected to the maingear through a double cardan
joint, which allows both the generator and the maingear to move independently. The way the
generator is wound gives maximum effeciency at half load. The cooling air for the
generator is taken directly from the outside to obtain the best possible cooling effect.
An electrical fan (not a mechanical) is used for cooling of the generator. In this way,
the fan is only in operation when cooling of the generator is needed, and the annual
production of the windturbine is increased. To avoid condensation water, a heating element
is built into the generator. |
BRAKE SYSTEM
The main brake system are the pivotable tips of the rotorblades, which under even extreme
conditions are capable of keeping the ideling speed of the rotor well below syncroneous
speed. For parking purposes the machine has a brake-system on the low speed side of the
main gear, and this brake system assures that no damaging knock loads from the rotor get
into the gear during parking time. In case of malfunction of pivotable tips, a fail safe
emergency brake is fitted on the high speed side of the main gear, which together with the
brake on the slow side is capable of braking the rotor down safely, under any condition.
In case of an emergency situation, the mechanical brakes will be applied simultaneously to
the aerodynamic brakes.
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YAW SYSTEM
The yaw system is based on a 4-point-ball-bearing type sleewing ring, with inner gears.
The yawing is done by two hydraulic driven planetary gears,
with built in spring loaded disk brakes. The yaw system is, additionally, fitted with 3
hydraulic activated yaw brakes, based on a disk/positive caliber system. When the nacelle
is yawing one yaw brake is smoothening the yawing, due to full load on the pads. When
there is no yaw operation the nacelle is fixed by the diskbrake in combination with the
gear brakes.
The whole hydraulic yaw system is made with respect to the well known and reliable Nordex
hydraulics fitted on the N29/250.
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TOWER
The N43/600 wind turbines can be supplied with either:
Tubular tower of 40, 50 or 60 m. hubheight, or
Lattice tower of 42 or 50 m. hubheight.
The tubular tower is a conic-shape tower which dimension decreases all the way up. A
ladder and safety-wire are installed in the tower, as well as platforms. The tubular tower
is sandblasted and painted white according to ISO 12944, Class 5.
The lattice tower is made of V-iron in the corners with UNP-iron as lattice. A ladder and
safety-line are also installed in the tower. The lattice tower is hot-dip galvanized.
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CONTROLLER
The wind turbine is supplied with a multi processor controller with a self diagnosing
system, which secures the wind turbines unattended operation under all conditions.
In case the wind turbine is supplied with a tubular tower, the controller is placed in the
bottom of the tower. For a lattice tower, a separate house is supplied for the controller.
The controller is supplied complete with switchgear, incoming MCB (Main Circuit Breaker),
protection devices, etc., and has a keyboard for display and easy readout of more than 200
functions. The keyboard can also be used for changing the operational parameters of the
wind turbine.
For maximum safety, the controller is fitted with a second overspeed protection based on
hard wire components, which operates separately from the controller.
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REMOTE MONITORING
All NORDEX wind turbines are prepared for remote monitoring and control. A
telephone-connection is all that is needed for this system to be functional. Remote
communication is done via a normal IBM-compatibel computer, where more than 200 different
functions can be read from the turbine. The software is included in the delivery by
NORDEX. In case of an error, the controller automatically reports this error, and data in
the controller is "frozen" so that it is possible to see what happened just
before, and when, the error occured.
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OPERATION &
SAFETY LOGISTICS
The NORDEX windturbines operate automatically. When the wind
increases from low values, the turbine will self-start at about 3-4 m/s average windspeed,
measured at hub height by the anemometer.
The wind turbine is self-starting, and does not need the generator for motorstart. The
generator is connected to the grid via the thyristors, shortly after to be by-passed by a
contactor. The advanced control of the thyristors assures the lowest possible peaks on the
grid.
If the 2-min. average windspeed exceeds 25 m/sec., the windturbine is shut down through
deployment of the aerodynamic brakes and application of the mechanical brake at lower rpm.
to bring the turbine to a standstill.
In case of an error, the turbine is shut down in a similar way.
However, by certain errors an emergency braking is required, and in these cases both
braking systems are activated simultaneously.
To avoid an emergency braking (which puts a lot of mechanical stress on the turbine) at
grid-drops, a UPS-system is installed. By the use of this battery-backup function it is
possible to make a normal braking of the turbine. This UPS-function is especially valuable
at locations where the grid is not always optimal.
As the blade tips form the main braking-system, this will secure a very smooth shut down
of the wind turbine. The blade tips are hydraulically retracted and are deployed at the
release of the hydraulic pressure. This release system is fail-safe and includes more
independent systems. These include monitoring of the rotor- and generatorspeed and
pressure relief valve. The pressure relief valve secures that the hydraulic pressure is
released in case of overspeed on the rotor.
Due to continuous development and improvement of our products, Nordex Balcke-Dürr GmbH
reserves the right to change the above
specifications without notice. |
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