Civil Engineering Reference
In-Depth Information
5
Wind Powe
r System
The wind power system is fully covered in this and the following two
chapters. This chapter covers the overall system level performance, design
considerations and trades. The electrical generator is covered in the next
chapter and the speed control in Chapter 7.
5.1
System Components
The wind power system is comprised of one or more units, operating elec-
trically in parallel, having the following components:
•
the tower.
•
the wind turbine with two or three blades.
•
the yaw mechanism such as the tail vane.
•
the mechanical gear.
•
the electrical generator.
•
the speed sensors and control.
The modern system often has the following additional components:
•
the power electronics.
•
the control electronics, usually incorporating a computer.
•
the battery for improving the load availability in stand-alone mode.
•
the transmission link connecting to the area grid.
Because of the large moment of inertia of the rotor, the design challenges
include the starting, the speed control during the power producing opera-
tion, and stopping the turbine when required. The eddy current or other
type of brake is used to halt the turbine when needed for emergency or for
routine maintenance. In the multiple tower wind farm, each turbine must
