Windy Nation Windtura 750 (No Slip Ring version) User Manual
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The Windtura 750 produces energy by capturing kinetic energy from the wind. The wind
is captured by three blades which use the wind’s kinetic energy to rotate a three phase AC
permanent magnet alternator. The rotation of the permanent magnet alternator (PMA)
produces electrical power which is transferred from the PMA to ground level by three electrical
wires.
In general, at ground level the three phase alternating current (AC) produced by the
PMA is rectified to direct current (DC). This is accomplished by using a three phase bridge
rectifier. WindyNation sells an 80 amp three phase bridge rectifier suitable for this task. Once
the three phase AC is rectified to DC, the electricity is generally used to (1) charge a 12 or 24
volt battery bank or (2) feed a grid tie inverter. The majority of customers use the Windtura 750
to charge 12 or 24 volt battery banks.
If the Windtura 750 is used to charge a 12 or 24 volt battery bank, there must be a
device in place to prevent the battery bank from being overcharged by the Windtura 750.
Additionally, this device must keep the Windtura 750 under an electrical load while the
Windtura
750
is
not
charging
the
battery
bank.
To
accomplish
both
these
tasks,
a
device
called
a
diversion
load
(or
dump
load)
charge
controller
is
used.
In
the
most
simple
terms,
a
diversion
load charge controller is a voltage monitoring device. The diversion load charge controller
monitors the voltage of the battery bank. When the voltage of the battery bank reaches a level
that indicates the battery bank is fully charged, the diversion load charge controller disconnects
the Windtura 750 from the battery bank. Because the Windtura 750 must stay under an
electrical load to operate safely, the diversion load charge controller connects the Windtura
750 to a diversion load. Generally, large wire wound resistors or heating elements are used as
the diversion loads. Once the battery bank’s voltage level drops from a fully charged level, the
charge controller senses this and switches the Windtura 750 back to charging the battery bank.
Overspeed
protection
in
high
winds:
All wind turbines need to be capable of protecting themselves in high wind conditions
(typically greater than 30-‐35 mph). If a wind turbine has no method of protection in high winds,
catastrophic failures can occur: (1) The blades will begin to spin too fast and will be under very
high stress, strain and tension forces. This could lead to the blades cracking or breaking.
Additionally,
the
noise
from
the
blades
will
be
very
loud
in
high
winds.
(2)
The
wind
turbine’s
generator
will
begin
to
rotate
at
very
high
rpms
and
the
current
(amps)
produced
by
the
generator might produce too much heat for the generator to handle. The intense heat will
overheat the generator and it will break.
The Windtura 750 uses a high wind protection method called furling. The tail assembly
of the Windtura 750 is attached to the yaw mount on a pivot bar angled at 20 degrees. The
pivot bar allows the generator and yaw mount to rotate away from the wind. At a wind speed
of approximately 30 mph, the rotational inertia of the blades begins to turn the blades and
generator “out of the wind”. As the wind speed increases, the Windtura 750 will continue to
turn “out of the wind” to almost 90 degrees. By turning “out of the wind”, the blades no longer
capture all of the wind’s kinetic energy and, therefore, the Windtura 750 is capable of