Download Small Wind Turbine System Components

Small Wind
Turbine System
Components
by Emily Sautter
Major components of the Bergey XL.1 Wind Turbine
A small wind energy system is typically comprised of a wind turbine, a tower, a controller, an inverter and, depending on the preference
of the consumer, a battery bank.
The major components to a small horizontal-axis wind turbine include blades, alternator, slip ring and brush assembly, nacelle, yaw
head, and tail assembly. Most horizontal-axis small wind turbines have three blades, typically made of fiberglass, glass polypropylene,
or some other composite material. The blades act like aircraft wings to convert the wind’s energy into rotational energy to turn the alternator. The alternator, most of which use permanent magnets, then converts the rotational energy into electricity. The nacelle provides housing for the alternator and wiring. The electricity produced by the alternator is transferred to the fixed cables running down
the turbine tower by a slip ring and brush assembly. This type of transfer allows the turbine to yaw or turn into the wind. The turbines
turn on the yaw head, which contains bearings and serves as the connection point of the turbine to the tower. Most small wind turbines have a tail boom and vane, which ensures the turbine is always oriented into the wind.
All turbines should have a breaking or slowing mechanism to protect the turbine in high wind speed events. Some turbines have breaking systems at the base of the tower, some turbines have special blade design in which the blades will pitch themselves out of high speed
winds, and Bergey small wind turbines have an auto-furl® mechanism in which the tail assembly “furls” the rotor away from high speed
winds.
Small wind turbines may be mounted on almost any tower. Options offered by most turbine manufacturers include lattice or monopole towers; guyed and non-guyed.
For battery charging turbines, the electricity from the turbine is run through a controller to rectify the AC current to DC current, to
prevent the system from overcharging the batteries, and to display battery voltage. The electricity is then fed into a battery bank, and
when the homeowner consumes the electricity, it is sent through an inverter to convert the DC to AC. For turbines connected in parallel to the grid, the electricity from the turbine is sent through a controller, then through an inverter, and then to the homeowner’s AC
distribution panel. In the event that the consumer is not using the electricity produced by the turbine, it flows through a connection to
a service transformer of the utility grid.
Certain Safety features should be included to protect grid-connected small renewable energy systems from being damaged or harming
people. These include safety disconnects; automatic and/or manual disconnects which protect the system from power surges or equipment malfunctions, allow for system maintenance, and if the system is grid-connected, the disconnects can isolate the system from the
grid for the safety of utility workers. Another important safety feature is grounding equipment; grounding equipment should provide
a well-defined, low resistant path from the turbine and system components to the ground to protect the system from lightning strikes
and equipment malfunctions. Lastly, look for surge protection to protect the system should it or nearby power lines be struck by lightning.
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