Co-ordination Action for Autonomous Desalination Units ... - ADU-RES

Nominal output 13.5 m/s
Cut-out wind speed 25 m/s
Tower Tubular cone-shaped
Height 30 m
Control system Made for VESTAS
Diesel engines: 2 engines
Power of each 160 KVA
Connection Mechanically through an electromagnetic
clutch to the flywheel
Flywheel Each can deliver a half of the envisaged peak
power demand -100 kW- during 30 seconds
Frequency minimum level
48 Hz
allowed
The three-bladed wind driven generator, with variable pitch and constant velocity,
and an induction type electricity generating machine, with double coil winding of six
and eight pairs of poles, respectively, enabling the operation of the generator at two
different wind speed regimes. Although the initial nominal power of the generator
was 225 kW, at the beginning of 2001 this nominal power was restricted to 130 kW
acting on the angle of pitch of the blades of the rotor.
c. Experiences and Lessons Learnt
The main observation during system operation, concerned with the mismatch
between the power output from the wind generator and the load of the system. The
generated energy exceeds the energy demand at the site, and hence a large dump
load is required in order to make up with the excess power.
The need to limit the nominal power of the wind-driven generator was due to the fact
that the actual energy demand turned out to be lower than had been estimated and
far less than the generator is capable of supplying at nominal power (225 kW). As a
result, when the wind speeds exceeded the 10 m/s at the height of the rotor shaft,
the generator would shut down due to over-frequency. Though it would have been
advantageous to be able to set variable nominal power limits lower than 130 kW as
also the manufacturer is advised.
The system began its operation in May 1995. However, given the fact that the growth
forecasts for the community as estimated by the Local Council of Pajara turned out
to be inaccurate and given the incorrect technical and economic management of the
WP2 ADU-RES 35