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