Table of Contents
Advertisement
Even More about Wind Turbines
A wind turbine is a mechanical device and, as such, it takes time for the rotor to rotate from 0 rpm
to whatever speed. And with a load is connected, the time to reach steady speed will be even
longer. Thus the output voltage from the wind turbine rises slowly as compared to that of a Solar
Panel. A solar panel is a semiconductor device whose response time is very fast.
When there is no load connected to the wind turbine, the output voltage is proportional to the
average wind speed of the swept area. You may compare this result with an Anemometer – a
device that uses small wind vanes to measure the speed of the wind.
You may notice that the output voltage fluctuates frequently and with many ripples on the plot.
This is a characteristic of wind turbine which shows that the wind is never steady. Even though
the output from the fan is very steady, the turbulence created by the wind still exists. A good wind
tunnel can minimize this.
The voltage ripple exists as a result of the 3-Phase generator. For each rotation, there are 6
ripples generated (2 ripple for each phase). However, due to the time scale resolution of the
system, this phenomenon cannot be demonstrated accurately.
The output voltage also changes with the distance between the wind turbine and the wind source.
The output voltage decreases if the wind turbine does not align with the wind. However, the
tm
WindCharge
will align itself automatically to face the wind.
Optimizing a Wind Turbine
A wind turbine cannot be efficient at all wind speed conditions. The blades have contradicting
requirements at high and low wind speed. At low wind speeds, the size of the blades should be
large and long, and with more blades. At high wind speeds, the size of the blades should be
narrow and short, and with fewer blades. Therefore, you are encouraged to test the wind turbine
with the supplied long and short blades. You may also create your own blades to see if they are
more efficient.
Play around with the Wind Turbine
tm
WindCharge
is a realistic mini wind turbine that you can use to power your electrical devices
apart from the experiment purposes. You may use it to charge rechargeable batteries, power
water pumps, driving motor fan, lighting a bulb and much more. You can bring your WindCharge
outdoor to experience the natural wind. However, you have to know that the voltage output from
the wind turbine can be more than 10 Volts under strong wind. To protect your electronic devices
from damage by the high voltage, always connect a rechargeable battery of suitable voltage
rating to clamp the voltage and serve as a reservoir to filter the fluctuation from the wind.
You may like to customize the WindCharge
use to make the blades and vane are readily available. Polypropylene sheet, Balsa wood, post
card or any sheet media can be used. What you need are scissors and a punch. You can color
your blades and vane to make them more attractive. You may also stick a picture on the vane
and share the fun with your friends. It is nice to display the WindCharge
friends. Use your imagination!!
tm
with your imagination. The materials that you can
55
tm
on your desk or your
Advertisement
Table of Contents
