Page 401 - Wind Energy Handbook

REFERENCES 375

accidental release and the occasional need to deactivate them for maintenance
purposes; the rotor locking device should act on the low-speed shaft, so that its
effectiveness is not dependent on the integrity of the gearbox – typically the
device consists of a pin mounted in a fixed housing, which can be engaged in a
hole in a shaft-mounted disc;

• guards to shield any rotating parts within the nacelle;

• suitable fixtures for the attachment of safety harnesses for personnel working
outside the nacelle.

The designer needs to assess the requirement for all-weather access to the nacelle
at an early stage. Lattice towers afford no protection from the weather when
climbing, so the number of days on which access for maintenance is possible will be
restricted. Similar restrictions will arise if the nacelle cover has to be opened to the
elements in order to provide space for personnel to enter.
Consideration also needs to be given to the means of raising and lowering tools
and spares. If the interior of the tower is interrupted by intermediate platforms,
these operations have to be performed outside, with consequent weather limit-
ations.
Standard rules for electrical safety apply to all electrical equipment. However,
particular care must be taken with the routing of electrical cables between tower
and nacelle, in order to avoid potential damage due to chafing when they twist. If
the power transformer is located in the tower base or nacelle instead of in a separate
enclosure at ground level, it should be partitioned off to minimize the fire risk to
personnel.

References

Armstrong, J. R. C. and Hancock, M., (1991). ‘Feasibility study of teetered, stall-regulated
rotors’. ETSU Report No. WN 6022.
Bossanyi, E. A. and Gamble, C. R., (1991). ‘Investigation of torque control using a variable
slip induction generator’ ETSU WN-6018, Energy Technology Support Unit, Harwell, UK.
Burton, A. L., Mill, P. W. and Simpson, P. B., (1990). ‘LS1 post-synchronization commission-
ing’. Proceedings of the 12th BWEA Conference, pp 183–193. Mechanical Engineering Pub-
lications, Bury St Edmunds, UK.
Coiante, D. et al., (1989). ‘Gamma 60 1.5 MW wind turbine generator’. Proceedings of the
European Wind Energy Conference, pp 1027–1032.
Corbet, D. C. and Morgan, C. A., (1991). ‘Passive control of horizontal axis wind turbines’.
Proceedings of the 13th BWEA Conference, pp 131–136. Mechanical Engineering Publications,
Bury St Edmunds, UK.
Derrick, A., (1992). ‘Aerodynamic characteristics of novel tip brakes and control devices for
HAWTs’. Proceedings of the 14th BWEA Conference, pp 73–78. Mechanical Engineering
Publications, Bury St Edmunds, UK.
Engstrom, S. et al., (1997). ‘Evaluation of the Nordic 1000 Prototype’. Proceedings of the
European Wind Energy Conference, pp 213–216.