Hardware Description; Contents Of This Chapter; Acs800-67 - ABB ACS800 Series Hardware Manual

Hardware description

Contents of this chapter

This chapter describes the construction of the converter.

ACS800-67

ACS800-67 wind turbine converter is designed for use with induction generators with
wound rotor and slip rings, such as the ABB AMK series. The converter is connected
between the generator rotor and the supply network. The converter can be installed
in the tower base or in the nacelle.
The speed of the rotor varies in relation to the wind speed. In order to keep the
speed optimal (i.e. somewhat higher than the synchronous speed of the generator),
the angle of the rotor blades is adjustable by means of a pitch drive. However,
adjusting the pitch is fairly slow. To compensate for faster changes in rotor speed,
the ACS800-67 quickly accelerates or decelerates the rotation speed of the field in
the rotor in order to retain the optimal slip. When the wind decreases, the converter
takes energy from the supply and accelerates the rotation of the rotor field so that
the stator remains capable of feeding energy to the grid. Likewise, the rotation of the
rotor field is decelerated at increasing wind speeds. The energy generated in the
rotor above the synchronous speed can also be fed to the grid.
The converter is also used for synchronising the stator output with the grid before the
actual grid connection. On disconnection, the converter adjusts the torque to zero.
This also decreases the stator current to zero so that the generator can be
disconnected.
The diagram below represents a typical application.
21
Hardware description