Environmental Engineering Reference
In-Depth Information
motor is connected to a series of gears which step up in size, decreasing the rate of
rotation at each step. The largest of these moves a worm gear, giving a huge
increase in the precision while simultaneously reducing backlash, with a total
gearbox ratio of r
tg
= 1/140. The worm moves two other gears, also stepping up in
size, the larger of which is directly connected to the nacelle. In this way, the
resulting pitch angle is the nacelle pitch angle relative to the horizontal axis
perpendicular to the wind direction. It is represented as b in Fig.
14.12
.
For the nacelle angle relative to the vertical axis, the yaw angle, we developed a
second gearbox to move the entire tower relative to the base (see Fig.
14.6
). This
gearbox is much less complex; however, it does reduce error from the motor and
increase precision. The base itself, aside from housing the motor and gearbox for
the yaw control, is built to be relatively heavy to anchor the system better. It also
allows for the NXT microcontroller to be attached. In this way, the resulting yaw
angle is the tower angle relative to the vertical axis that passes through the center
of the tower. It is represented as a in Fig.
14.12
.
14.2.1.3 Electrical Components: Generator, Grid Connection
The wind turbines use a DC motor made by LEGO as a simple generator (the
E-motor)—see Fig.
14.2
, element (2) and Fig.
14.7
a. It has a single rotor and a
small gearbox with a 9.5:1 gearing ratio. It can either induce a voltage or be
Fig. 14.6 Yaw system: motor, gearbox, mechanical configuration, tower and foundation
