Page 197 - Fluid Power Engineering

CHAPTER9

Wind Turbine

Generator (WTG)

Components

Introduction
In this chapter, the main components of a utility-scale horizontal axis
wind turbine are described. Wind turbine generators (WTG) have
evolved into complex machines, much like simpler car engines have
evolved into complex machines. At a high level, there are three major
systems:
1. Rotor system. This includes blades that capture energy and a
rotor hub that connects the blades to the shaft, along with
pitch mechanism that assists in efficient capture of energy.
2. Nacelle. This contains all the components that sit on top of the
tower, except the rotor system. It includes main shaft, gear-
box, generator, brake, bearings, nacelle frame, yaw mecha-
nism, auxiliary crane, hydraulic system, and cooling system.
Depending on the design of the turbine, only some of the
components may be present.
3. Tower and foundation. These structural elements carry all the
forces and moments to the ground.
At the end of the chapter two additional topics are covered: De-
sign loads and certification of turbines. The chapter concludes with
technical specifications of four WTGs.

Rotor System
The rotor system captures wind energy and converts into rotational
kinetic energy. This is accomplished through blades that connect to

169