Environmental Engineering Reference
In-Depth Information
to transfer active power unidirectionally but is capable of injecting or absorbing reactive
power from the grid.
At the time of writing a new generation of wind turbines based on what is known as the
'Multibrid' principle are being developed. These are a halfway house between the traditional
systems that use high gearing and the more recent offerings that employ gearless coupling.
The 'Multibrid' machines use a gearbox of moderate gearing driving a synchronous generator
of moderate diameter, the whole system being packaged in a compact unit. Only time will
tell whether direct drive schemes or 'Multibrids' will eventually supplant the well entrenched
technology of variable slip induction generators.
Technical details of the various wind turbine generator concepts presented in this section
can be found in References [8 - 10] .
References
[1] Smith , R.J. and Dorf , R.C. Circuits ,
Devices and Systems
, 5th edition, John Wiley & Sons, Ltd, Chichester.
[2] Gross , C.A.
Power System Analysis
, John Wiley & Sons, Ltd, Chichester, 1986 .
[3] Lander , C.W.
Power Electronics
McGraw - Hill , Maidenhead , 1987 .
[4] Slootweg , H. and De Vries , E. ' Inside wind turbines: fi xed vs variable speed',
Renewable Energy World
,
January - February 31 - 40 .
[5] Pedersen , T.K. ' Semi - variable speed operation - a compromise? ' Vestas - Danish Wind Technology A/S,
Denmark, EWEA 1995 European Conference.
[6] Kruger and Andersen , B. ' Vestas Optispeed - advanced control strategy for variable speed wind turbines ' ,
Department for Research and Development, Vestas Wind Systems A/S, Jacobsens Vej 7, DK-6950
Ringkobing.
[7] Ekanayake , J. , Holsworth , L. and Jenkins , N. ' Control of DFIG wind turbines '
IEE Power Engineering Journal
,
February 2003 .
[8] Heier , S.
Grid Integration of Wind Energy Conversion Systems
, 2nd edition, John Wiley & Sons, Ltd, Chich-
ester , 2006 .
[9] Ackerman , T. ' Transmission systems for off - shore wind farms ' ,
Renewable Energy world
, July - August 2002 ,
49 - 61 .
[10] Danish Wind Industry Association website www.windpower.dk .
